Časť 4: Spustime to aj tak Linux na RocketChip RISC-V

Časť 4: Spustime to aj tak Linux na RocketChip RISC-V Na obrázku Linux Jadro vám posiela pozdravy cez GPIO.

V tejto časti príbehu o portovaní RISC-V RocketChip na čínsku dosku s Cyclone IV konečne spustíme... LinuxTaktiež sa naučíme, ako si sami nakonfigurovať pamäťový radič IP Core a mierne upraviť popis DTS hardvéru. Tento článok je pokračovaním... tretia časť, ale na rozdiel od pomerne rozsiahlej predchádzajúcej bude dosť krátka.

… Pretože setup_smp volaný iba v prípade, že je jadro nakonfigurované s podporou SMP, môžete skúsiť vypnúť viacjadrové. Nepríjemné bude, ak potrebujem implementovať podporu atomicity aj do pamäťového modulu (zdalo sa mi, že vyrovnávacia pamäť sa s tým popasuje sama), ale v jednojadrovom prípade by nám to nemalo prekážať.

Stále nevyletel...

[    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80200000
[    0.000000] Linux version 4.19.0-sifive-1+ (trosinenko@trosinenko-pc) (gcc version 8.3.0 (Buildroot 2019.02-07449-g4eddd28f99)) #1 Thu Jul 4 18:38:10 MSK 2019
[    0.000000] bootconsole [early0] enabled
[    0.000000] Initial ramdisk at: 0x(____ptrval____) (16777216 bytes)
[    0.000000] Zone ranges:
[    0.000000]   DMA32    [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000]   Normal   [mem 0x00000000c0000000-0x00000bffffffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000] software IO TLB: mapped [mem 0xbb1fc000-0xbf1fc000] (64MB)
[    0.000000] Unable to find "cpu" devicetree entry
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 258055
[    0.000000] Kernel command line: debug console=ttySIF0,125200 root=/dev/mmcblk0p2 loglevel=7 rootwait
[    0.000000] Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes)
[    0.000000] Inode-cache hash table entries: 65536 (order: 7, 524288 bytes)
[    0.000000] Sorting __ex_table...
[    0.000000] BUG: Bad page state in process swapper  pfn:80bf7
[    0.000000] page:ffffffe03f029e08 count:0 mapcount:-65280 mapping:0000000000000000 index:0x1
[    0.000000] flags: 0x0()
[    0.000000] raw: 0000000000000000 0000000000000100 0000000000000200 0000000000000000
[    0.000000] raw: 0000000000000001 0000000000000000 00000000ffff00ff
[    0.000000] page dumped because: nonzero mapcount
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-sifive-1+ #1
[    0.000000] Call Trace:
[    0.000000] [<ffffffe00002cfde>] walk_stackframe+0x0/0xa0
[    0.000000] [<ffffffe00002d1da>] show_stack+0x2a/0x34
[    0.000000] [<ffffffe00063c898>] chachachllachachachTradeonachachach_inachachipachachachachllachachachTradeonachachachdevachachachypachachachllachachachTradeona+0x20/0x28
[    0.000000] [<ffffffe00009499c>] bad_page+0xe4/0x102
[    0.000000] [<ffffffe0000949f2>] free_pages_check_bad+0x38/0x7a
[    0.000000] [<ffffffe000094bb0>] free_pcppages_bulk+0x106/0x36c
[    0.000000] [<ffffffe0000957be>] free_unref_page_commit.isra.23+0x86/0x8e
[    0.000000] [<ffffffe0000960bc>] free_unref_page+0x44/0x58
[    0.000000] [<ffffffe0000960de>] __free_pages.part.28+0xe/0x22
[    0.000000] [<ffffffe0000056da>] __free_pages_bootmem+0x86/0x90
[    0.000000] [<ffffffe000007c46>] free_all_bootmem+0x156/0x1ba
[    0.000000] [<ffffffe0000023f8>] mem_init+0x36/0x44
[    0.000000] [<ffffffe0000007a0>] start_kernel+0x1aa/0x328
[    0.000000] [<ffffffe000000058>] _sinittext+0x58/0x5c
[    0.000000] Disabling lock debugging due to kernel taint
[    0.000000] BUG: Bad page state in process swapper  pfn:80bf9
[    0.000000] page:ffffffe03f029e78 count:0 mapcount:-65280 mapping:0000000000000000 index:0x0
[    0.000000] flags: 0x0()
[    0.000000] raw: 0000000000000000 ffffffe03f020080 ffffffe03f020080 0000000000000000
[    0.000000] raw: 0000000000000000 0000000000000000 00000000ffff00ff
[    0.000000] page dumped because: nonzero mapcount
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G    B             4.19.0-sifive-1+ #1
[    0.000000] Call Trace:
[    0.000000] [<ffffffe00002cfde>] walk_stackframe+0x0/0xa0
[    0.000000] [<ffffffe00002d1da>] show_stack+0x2a/0x34
[    0.000000] [<ffffffe00063c898>] chachachllachachachTradeonachachach_inachachipachachachachllachachachTradeonachachachdevachachachypachachachllachachachTradeona+0x20/0x28
[    0.000000] [<ffffffe00009499c>] bad_page+0xe4/0x102
[    0.000000] [<ffffffe0000949f2>] free_pages_check_bad+0x38/0x7a
[    0.000000] [<ffffffe0000955c6>] __free_pages_ok+0x3fe/0x430
[    0.000000] [<ffffffe0000960ea>] __free_pages.part.28+0x1a/0x22
[    0.000000] [<ffffffe0000056da>] __free_pages_bootmem+0x86/0x90
[    0.000000] [<ffffffe000007c46>] free_all_bootmem+0x156/0x1ba
[    0.000000] [<ffffffe0000023f8>] mem_init+0x36/0x44
[    0.000000] [<ffffffe0000007a0>] start_kernel+0x1aa/0x328
[    0.000000] [<ffffffe000000058>] _sinittext+0x58/0x5c
[    0.000000] BUG: Bad page state in process swapper  pfn:80bfa
[    0.000000] page:ffffffe03f029eb0 count:0 mapcount:-65280 mapping:0000000000000000 index:0x0
[    0.000000] flags: 0x0()
[    0.000000] raw: 0000000000000000 ffffffe03f0200b8 ffffffe03f0200b8 0000000000000000
[    0.000000] raw: 0000000000000000 0000000000000000 00000000ffff00ff
[    0.000000] page dumped because: nonzero mapcount
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G    B             4.19.0-sifive-1+ #1
[    0.000000] Call Trace:
[    0.000000] [<ffffffe00002cfde>] walk_stackframe+0x0/0xa0
[    0.000000] [<ffffffe00002d1da>] show_stack+0x2a/0x34
[    0.000000] [<ffffffe00063c898>] chachachllachachachTradeonachachach_inachachipachachachachllachachachTradeonachachachdevachachachypachachachllachachachTradeona+0x20/0x28
[    0.000000] [<ffffffe00009499c>] bad_page+0xe4/0x102
[    0.000000] [<ffffffe0000949f2>] free_pages_check_bad+0x38/0x7a
[    0.000000] [<ffffffe0000955c6>] __free_pages_ok+0x3fe/0x430
[    0.000000] [<ffffffe0000960ea>] __free_pages.part.28+0x1a/0x22
[    0.000000] [<ffffffe0000056da>] __free_pages_bootmem+0x86/0x90
[    0.000000] [<ffffffe000007c46>] free_all_bootmem+0x156/0x1ba
[    0.000000] [<ffffffe0000023f8>] mem_init+0x36/0x44
[    0.000000] [<ffffffe0000007a0>] start_kernel+0x1aa/0x328
[    0.000000] [<ffffffe000000058>] _sinittext+0x58/0x5c
[    0.000000] BUG: Bad page state in process swapper  pfn:80bfb
[    0.000000] page:ffffffe03f029ee8 count:0 mapcount:-65280 mapping:0000000000000000 index:0x0
[    0.000000] flags: 0x0()
[    0.000000] raw: 0000000000000000 ffffffe03f0200f0 ffffffe03f0200f0 0000000000000000
[    0.000000] raw: 0000000000000000 0000000000000000 00000000ffff00ff
[    0.000000] page dumped because: nonzero mapcount
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G    B             4.19.0-sifive-1+ #1
[    0.000000] Call Trace:
[    0.000000] [<ffffffe00002cfde>] walk_stackframe+0x0/0xa0
[    0.000000] [<ffffffe00002d1da>] show_stack+0x2a/0x34
[    0.000000] [<ffffffe00063c898>] chachachllachachachTradeonachachach_inachachipachachachachllachachachTradeonachachachdevachachachypachachachllachachachTradeona+0x20/0x28
[    0.000000] [<ffffffe00009499c>] bad_page+0xe4/0x102
[    0.000000] [<ffffffe0000949f2>] free_pages_check_bad+0x38/0x7a
[    0.000000] [<ffffffe0000955c6>] __free_pages_ok+0x3fe/0x430
[    0.000000] [<ffffffe0000960ea>] __free_pages.part.28+0x1a/0x22
[    0.000000] [<ffffffe0000056da>] __free_pages_bootmem+0x86/0x90
[    0.000000] [<ffffffe000007c46>] free_all_bootmem+0x156/0x1ba
[    0.000000] [<ffffffe0000023f8>] mem_init+0x36/0x44
[    0.000000] [<ffffffe0000007a0>] start_kernel+0x1aa/0x328
[    0.000000] [<ffffffe000000058>] _sinittext+0x58/0x5c
[    0.000000] BUG: Bad page state in process swapper  pfn:80bfc
[    0.000000] page:ffffffe03f029f20 count:0 mapcount:-65280 mapping:0000000000000000 index:0x0
[    0.000000] flags: 0x0()
[    0.000000] raw: 0000000000000000 ffffffe03f020028 ffffffe03f020028 0000000000000000
[    0.000000] raw: 0000000000000000 0000000000000000 00000000ffff00ff
...

Je zaujímavé, že po všetkom ladení som sa rozhodol pozrieť na to, ako by mal vyzerať výstup „referenčného“ jadra, povedal make qemua videl podobnú chybu.

Bohužiaľ, ďalšia úroveň (Linux jadro) je zložitejšie: GDB, pripojené cez JTAG k RocketChip, zrejme pracuje s fyzickými adresami bez ohľadu na to, ako je nakonfigurovaná MMU, a jadro v momente, ktorý nás zaujíma, už nakonfigurovalo mapovanie adries, takže je ľahké povedať display/10i $pc nevyjde to - uvidíme len veľa unimp. Ale ak sme už zistili posun (zdá sa, že 0x80200000 -> 0xffffffe000000000), potom môžete podvádzať:

1: x/10i $pc
=> 0xffffffe000002436 <setup_smp>:      unimp
   0xffffffe000002438 <setup_smp+2>:    unimp
   0xffffffe00000243a <setup_smp+4>:    unimp
   0xffffffe00000243c <setup_smp+6>:    unimp
   0xffffffe00000243e <setup_smp+8>:    unimp
   0xffffffe000002440 <setup_smp+10>:   unimp
   0xffffffe000002442 <setup_smp+12>:   unimp
   0xffffffe000002444 <setup_smp+14>:   unimp
   0xffffffe000002446 <setup_smp+16>:   unimp
   0xffffffe000002448 <setup_smp+18>:   unimp
(gdb) undisplay 1
(gdb) display/10i ($pc - 0xffffffe000002436 + 0x80202436)
2: x/10i ($pc - 0xffffffe000002436 + 0x80202436)
   0x80202436:  addi    sp,sp,-96
   0x80202438:  sd      s0,80(sp)
   0x8020243a:  sd      s1,72(sp)
   0x8020243c:  sd      s2,64(sp)
   0x8020243e:  sd      s3,56(sp)
   0x80202440:  sd      s4,48(sp)
   0x80202442:  sd      s5,40(sp)
   0x80202444:  sd      s6,32(sp)
   0x80202446:  sd      s7,24(sp)
   0x80202448:  sd      s8,16(sp)

Body zlomu sa nastavujú rovnakým spôsobom:

(gdb) p setup_smp
$1 = {<text variable, no debug info>} 0xffffffe000002436 <setup_smp>
(gdb) b *0x80202436
Breakpoint 1 at 0x80202436
(gdb) c
Continuing.

Program received signal SIGTRAP, Trace/breakpoint trap.
setup_smp () at /home/trosinenko/freedom-u-sdk/linux/arch/riscv/kernel/smpboot.c:58
58              while ((dn = of_find_node_by_type(dn, "cpu"))) {
(gdb) bt
#0  setup_smp () at /home/trosinenko/freedom-u-sdk/linux/arch/riscv/kernel/smpboot.c:58
#1  0xffffffe0000022a2 in setup_arch () at /home/trosinenko/freedom-u-sdk/linux/arch/riscv/kernel/setup.c:253
#2  0x0000000000000000 in ?? ()
Backtrace stopped: frame did not save the PC

Aby ste sa mohli pohnúť ďalej, musíte ich ručne odstrániť - pre GDB je to nejaká úplne nepochopiteľná pasca. Ach áno, ak náhodou povieš s alebo n namiesto si, gdb sa pokúsi vložiť implicitný bod prerušenia, ktorý z pochopiteľných dôvodov nebude nastavený, ale neexistuje spôsob, ako odradiť GDB. S reštartom dosky sa však neponáhľajte - podľa mojich pozorovaní stačí reštartovať iba gdb (všimnite si, že staré body prerušenia nemusia zmiznúť).

V skutočnosti sa budete musieť vysporiadať s pôvodným problémom: umiestnením ladenia printk do funkcie of_find_node_by_type, ktorý používa vyhľadávací kód jadra zavádzacieho procesora, ukazuje, že namiesto názvov typov zariadení vidí nejaký druh odpadu. Napríklad odniekiaľ preberá riadok „Sériový port“, hoci to zjavne nie je v poli dtb device_type. Po vyhľadaní týchto bajtov v obraze jadra som ich našiel, pozrel sa na offset a uvedomil som si zrejmé: veľkosť jadra v zavádzacích parametroch je jednoznačne podhodnotená: má pridelených 8 Mb, ale zaberá viac ako desať. Pridelil som 16Mb, ale podivnosť neprestávala. Po tanci s čítaním FDT z rôznych adries (bežne sa adresa prenesie do jadra v registri a1), nakoniec som sa rozhodol stopovať, ale čo už сейчас je to tam analyzované. Našťastie namiesto toho, aby ste chodili s debuggerom (a pamätáme si, že existujú nuansy s prekladom adries, ktoré je stále potrebné vyriešiť tak či onak), môžete jednoducho a berličkami v súbore drivers/of/fdt.c vypichnúť #define pr_debug printk. Výsledkom bolo:

pridanie výstupu ladenia

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 3db0d71d128b..fac47df9d1db 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -173,6 +173,7 @@ asmlinkage void __init setup_vm(void)

 void __init parse_dtb(unsigned int hartid, void *dtb)
 {
+       printk("HART = %u DTB = %lxn", hartid, dtb);
        early_init_dt_scan(__va(dtb));
 }

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 74eaedd5b860..c019e4158e1d 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -940,10 +940,12 @@ struct device_node *of_find_node_by_type(struct device_node *from,
        unsigned long flags;

        raw_spin_lock_irqsave(&devtree_lock, flags);
-       for_each_of_allnodes_from(from, np)
+       for_each_of_allnodes_from(from, np) {
+               printk("%lx %lx [%s] | [%s]n", from, np, np->type, type);
                if (np->type && (of_node_cmp(np->type, type) == 0)
                    && of_node_get(np))
                        break;
+       }
        of_node_put(from);
        raw_spin_unlock_irqrestore(&devtree_lock, flags);
        return np;
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 800ad252cf9c..2b45870ebada 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -31,6 +31,8 @@

 #include "of_private.h"

+#define pr_debug printk
+
 /*
  * of_fdt_limit_memory - limit the number of regions in the /memory node
  * @limit: maximum entries
@@ -1253,6 +1255,7 @@ bool __init early_init_dt_scan(void *params)
  */
 void __init unflatten_device_tree(void)
 {
+       printk("INITIAL: %lxn", initial_boot_params);
        __unflatten_device_tree(initial_boot_params, NULL, &of_root,
                                early_init_dt_alloc_memory_arch, false);

Výstup na hardvér

                SIFIVE, INC.

         5555555555555555555555555
        5555                   5555
       5555                     5555
      5555                       5555
     5555       5555555555555555555555
    5555       555555555555555555555555
   5555                             5555
  5555                               5555
 5555                                 5555
5555555555555555555555555555          55555
 55555           555555555           55555
   55555           55555           55555
     55555           5           55555
       55555                   55555
         55555               55555
           55555           55555
             55555       55555
               55555   55555
                 555555555
                   55555
                     5

           SiFive RISC-V Core IP
 {
  #address-cells = <0x00000001>;
  #size-cells = <0x00000001>;
  compatible = "freechips,rocketchip-unknown-dev";
  model = "freechips,rocketchip-unknown";
  chosen {
    linux,initrd-start = <0x82000000>;
    riscv,kernel-end = <0x81200000>;
    riscv,kernel-start = <0x80200000>;
    #address-cells = <0x00000001>;
    #size-cells = <0x00000000>;
    bootargs = <0x64656275 0x6720636f 0x6e736f6c 0x653d7474 0x79534946 0x302c3132 0x35323030 0x20726f6f 0x743d2f64 0x65762f6d 0x6d63626c 0x6b307032 0x206c6f67 0x6c657665 0x6c3d3720 0x726f6f74 0x77616974>;
  }
  firmware {
    sifive,uboot = "YYYY-MM-DD";
  }
  aliases {
    serial0 = <0x2f736f63 0x2f736572 0x69616c40 0x36343030 0x30303030>;
  }
  cpus {
    #address-cells = <0x00000001>;
    #size-cells = <0x00000000>;
    cpu@0 {
      device_type = "cpu";
      clock-frequency = <0x00000000>;
      compatible = "sifive,rocket0", "riscv";
      d-cache-block-size = <0x00000010>;
      d-cache-sets = <0x00000040>;
      d-cache-size = <0x00001000>;
      d-tlb-sets = <0x00000001>;
      d-tlb-size = <0x00000020>;
      i-cache-block-size = <0x00000010>;
      i-cache-sets = <0x00000040>;
      i-cache-size = <0x00001000>;
      i-tlb-sets = <0x00000001>;
      i-tlb-size = <0x00000020>;
      mmu-type = "riscv,sv39";
      next-level-cache = <0x00000001>;
      reg = <0x00000000>;
      riscv,isa = "rv64imafdc";
      status = "okay";
      timebase-frequency = <0x000f4240>;
      tlb-split;
      interrupt-controller {
        #interrupt-cells = <0x00000001>;
        compatible = "riscv,cpu-intc";
        interrupt-controller;
        phandle = <0x00000002>;
      }
    }
  }
  ram@80000000 {
    device_type = "memory";
    reg = <0x80000000 0x40000000>;
    reg-names = "mem";
    phandle = <0x00000001>;
  }
  soc {
    #address-cells = <0x00000001>;
    #size-cells = <0x00000001>;
    compatible = "freechips,rocketchip-unknown-soc", "simple-bus";
    ranges;
    clint@2000000 {
      compatible = "riscv,clint0";
      interrupts-extended = <0x00000002 0x00000003 0x00000002 0x00000007>;
      reg = <0x02000000 0x00010000>;
      reg-names = "control";
    }
    debug-controller@0 {
      compatible = "sifive,debug-013", "riscv,debug-013";
      interrupts-extended = <0x00000002 0x0000ffff>;
      reg = <0x00000000 0x00001000>;
      reg-names = "control";
    }
    gpio@64002000 {
      #gpio-cells = <0x00000002>;
      #interrupt-cells = <0x00000002>;
      compatible = "sifive,gpio0";
      gpio-controller;
      interrupt-controller;
      interrupt-parent = <0x00000003>;
      interrupts = <0x00000003 0x00000004 0x00000005 0x00000006 0x00000007 0x00000008>;
      reg = <0x64002000 0x00001000>;
      reg-names = "control";
    }
    interrupt-controller@c000000 {
      #interrupt-cells = <0x00000001>;
      compatible = "riscv,plic0";
      interrupt-controller;
      interrupts-extended = <0x00000002 0x0000000b 0x00000002 0x00000009>;
      reg = <0x0c000000 0x04000000>;
      reg-names = "control";
      riscv,max-priority = <0x00000007>;
      riscv,ndev = <0x00000008>;
      phandle = <0x00000003>;
    }
    rom@10000 {
      compatible = "sifive,maskrom0";
      reg = <0x00010000 0x00002000>;
      reg-names = "mem";
    }
    serial@64000000 {
      compatible = "sifive,uart0";
      interrupt-parent = <0x00000003>;
      interrupts = <0x00000002>;
      reg = <0x64000000 0x00001000>;
      reg-names = "control";
    }
    spi@64001000 {
      #address-cells = <0x00000001>;
      #size-cells = <0x00000000>;
      compatible = "sifive,spi0";
      interrupt-parent = <0x00000003>;
      interrupts = <0x00000001>;
      reg = <0x64001000 0x00001000>;
      reg-names = "control";
      mmc@0 {
        compatible = "mmc-spi-slot";
        disable-wp;
        reg = <0x00000000>;
        spi-max-frequency = <0x01312d00>;
        voltage-ranges = <0x00000ce4 0x00000ce4>;
      }
    }
    tlclk {
      #clock-cells = <0x00000000>;
      clock-frequency = <0x017d7840>;
      clock-output-names = "tlclk";
      compatible = "fixed-clock";
    }
  }
}
[    0.000000] HART = 0 DTB = 81200000
[    0.000000] search "chosen", depth: 0, uname:
[    0.000000] search "chosen", depth: 1, uname: chosen
[    0.000000] Looking for initrd properties...
[    0.000000] Command line is: debug console=ttySIF0,125200 root=/dev/mmcblk0p2 loglevel=7 rootwait
[    0.000000] dt_root_size_cells = 1
[    0.000000] dt_root_addr_cells = 1
[    0.000000] memory scan node ram@80000000, reg size 8,
[    0.000000]  - 80000000 ,  40000000
[    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80200000
[    0.000000] Linux version 4.19.0-sifive-1+ (trosinenko@trosinenko-pc) (gcc version 8.3.0 (Buildroot 2019.02-07449-g4eddd28f99)) #1 SMP Sat Jul 6 12:14:41 MSK 2019
[    0.000000] bootconsole [early0] enabled
[    0.000000] initrd not found or empty - disabling initrd
[    0.000000] Zone ranges:
[    0.000000]   DMA32    [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000]   Normal   [mem 0x00000000c0000000-0x00000bffffffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000] INITIAL: ffffffe001000000
[    0.000000]  -> unflatten_device_tree()
[    0.000000] Unflattening device tree:
[    0.000000] magic: d00dfeed
[    0.000000] size: 00001000
[    0.000000] version: 00000011
[    0.000000]   size is 13512, allocating...
[    0.000000]   unflattening (____ptrval____)...
[    0.000000] fixed up name for  ->
[    0.000000] fixed up name for chosen -> chosen
[    0.000000] fixed up name for firmware -> firmware
[    0.000000] fixed up name for aliases -> aliases
[    0.000000] fixed up name for cpus -> cpus
[    0.000000] fixed up name for cpu@0 -> cpu
[    0.000000] fixed up name for interrupt-controller -> interrupt-controller
[    0.000000] fixed up name for ram@80000000 -> ram
[    0.000000] fixed up name for soc -> soc
[    0.000000] fixed up name for clint@2000000 -> clint
[    0.000000] fixed up name for debug-controller@0 -> debug-controller
[    0.000000] fixed up name for gpio@64002000 -> gpio
[    0.000000] fixed up name for interrupt-controller@c000000 -> interrupt-controller
[    0.000000] fixed up name for rom@10000 -> rom
[    0.000000] fixed up name for serial@64000000 -> serial
[    0.000000] fixed up name for spi@64001000 -> spi
[    0.000000] fixed up name for mmc@0 -> mmc
[    0.000000] fixed up name for tlclk -> tlclk
[    0.000000]  <- unflatten_device_tree()
[    0.000000] software IO TLB: mapped [mem 0xbb1fc000-0xbf1fc000] (64MB)
[    0.000000] 0 ffffffe03effcab0 [attach() failed for %s with error %d
[    0.000000] ] | [cpu]
[    0.000000] 0 ffffffe03eff0020 [(null)] | [cpu]

Výstup do QEMU

                SIFIVE, INC.

         5555555555555555555555555
        5555                   5555
       5555                     5555
      5555                       5555
     5555       5555555555555555555555
    5555       555555555555555555555555
   5555                             5555
  5555                               5555
 5555                                 5555
5555555555555555555555555555          55555
 55555           555555555           55555
   55555           55555           55555
     55555           5           55555
       55555                   55555
         55555               55555
           55555           55555
             55555       55555
               55555   55555
                 555555555
                   55555
                     5

           SiFive RISC-V Core IP
 {
  #address-cells = <0x00000002>;
  #size-cells = <0x00000002>;
  compatible = "riscv-virtio";
  model = "riscv-virtio,qemu";
  chosen {
    linux,initrd-start = <0x00000000 0x88000000>;
    linux,initrd-end = <0x00000000 0x88442b86>;
    riscv,kernel-start = <0x00000000 0x80200000>;
    riscv,kernel-end = <0x00000000 0x80c482ac>;
    bootargs = "";
    stdout-path = <0x2f756172 0x74403130 0x30303030>;
  }
  uart@10000000 {
    interrupts = <0x0000000a>;
    interrupt-parent = <0x00000002>;
    clock-frequency = <0x00384000>;
    reg = <0x00000000 0x10000000 0x00000000 0x00000100>;
    compatible = "ns16550a";
  }
  test@100000 {
    reg = <0x00000000 0x00100000 0x00000000 0x00001000>;
    compatible = "sifive,test0";
  }
  virtio_mmio@10008000 {
    interrupts = <0x00000008>;
    interrupt-parent = <0x00000002>;
    reg = <0x00000000 0x10008000 0x00000000 0x00001000>;
    compatible = "virtio,mmio";
  }
  virtio_mmio@10007000 {
    interrupts = <0x00000007>;
    interrupt-parent = <0x00000002>;
    reg = <0x00000000 0x10007000 0x00000000 0x00001000>;
    compatible = "virtio,mmio";
  }
  virtio_mmio@10006000 {
    interrupts = <0x00000006>;
    interrupt-parent = <0x00000002>;
    reg = <0x00000000 0x10006000 0x00000000 0x00001000>;
    compatible = "virtio,mmio";
  }
  virtio_mmio@10005000 {
    interrupts = <0x00000005>;
    interrupt-parent = <0x00000002>;
    reg = <0x00000000 0x10005000 0x00000000 0x00001000>;
    compatible = "virtio,mmio";
  }
  virtio_mmio@10004000 {
    interrupts = <0x00000004>;
    interrupt-parent = <0x00000002>;
    reg = <0x00000000 0x10004000 0x00000000 0x00001000>;
    compatible = "virtio,mmio";
  }
  virtio_mmio@10003000 {
    interrupts = <0x00000003>;
    interrupt-parent = <0x00000002>;
    reg = <0x00000000 0x10003000 0x00000000 0x00001000>;
    compatible = "virtio,mmio";
  }
  virtio_mmio@10002000 {
    interrupts = <0x00000002>;
    interrupt-parent = <0x00000002>;
    reg = <0x00000000 0x10002000 0x00000000 0x00001000>;
    compatible = "virtio,mmio";
  }
  virtio_mmio@10001000 {
    interrupts = <0x00000001>;
    interrupt-parent = <0x00000002>;
    reg = <0x00000000 0x10001000 0x00000000 0x00001000>;
    compatible = "virtio,mmio";
  }
  cpus {
    #address-cells = <0x00000001>;
    #size-cells = <0x00000000>;
    timebase-frequency = <0x00989680>;
    cpu@0 {
      device_type = "cpu";
      reg = <0x00000000>;
      status = "okay";
      compatible = "riscv";
      riscv,isa = "rv64imafdcsu";
      mmu-type = "riscv,sv48";
      clock-frequency = <0x3b9aca00>;
      interrupt-controller {
        #interrupt-cells = <0x00000001>;
        interrupt-controller;
        compatible = "riscv,cpu-intc";
        linux,phandle = <0x00000001>;
        phandle = <0x00000001>;
      }
    }
  }
  memory@80000000 {
    device_type = "memory";
    reg = <0x00000000 0x80000000 0x00000000 0x40000000>;
  }
  soc {
    #address-cells = <0x00000002>;
    #size-cells = <0x00000002>;
    compatible = "simple-bus";
    ranges;
    pci@30000000 {
      interrupt-map-mask = <0x00001800 0x00000000 0x00000000 0x00000007>;
      interrupt-map = <0x00000000 0x00000000 0x00000000 0x00000001 0x00000002 0x00000020 0x00000000 0x00000000 0x00000000 0x00000002 0x00000002 0x00000021 0x00000000 0x00000000 0x00000000 0x00000003 0x00000002 0x00000022 0x00000000 0x00000000 0x00000000 0x00000004 0x00000002 0x00000023 0x00000800 0x00000000 0x00000000 0x00000001 0x00000002 0x00000021 0x00000800 0x00000000 0x00000000 0x00000002 0x00000002 0x00000022 0x00000800 0x00000000 0x00000000 0x00000003 0x00000002 0x00000023 0x00000800 0x00000000 0x00000000 0x00000004 0x00000002 0x00000020 0x00001000 0x00000000 0x00000000 0x00000001 0x00000002 0x00000022 0x00001000 0x00000000 0x00000000 0x00000002 0x00000002 0x00000023 0x00001000 0x00000000 0x00000000 0x00000003 0x00000002 0x00000020 0x00001000 0x00000000 0x00000000 0x00000004 0x00000002 0x00000021 0x00001800 0x00000000 0x00000000 0x00000001 0x00000002 0x00000023 0x00001800 0x00000000 0x00000000 0x00000002 0x00000002 0x00000020 0x00001800 0x00000000 0x00000000 0x00000003 0x00000002 0x00000021 0x00001800 0x00000000 0x00000000 0x00000004 0x00000002 0x00000022>;
      ranges = <0x01000000 0x00000000 0x00000000 0x00000000 0x03000000 0x00000000 0x00010000 0x02000000 0x00000000 0x40000000 0x00000000 0x40000000 0x00000000 0x40000000>;
      reg = <0x00000000 0x30000000 0x00000000 0x10000000>;
      dma-coherent;
      bus-range = <0x00000000 0x000002ff>;
      linux,pci-domain = <0x00000000>;
      device_type = "pci";
      compatible = "pci-host-ecam-generic";
      #size-cells = <0x00000002>;
      #interrupt-cells = <0x00000001>;
      #address-cells = <0x00000003>;
    }
    interrupt-controller@c000000 {
      linux,phandle = <0x00000002>;
      phandle = <0x00000002>;
      riscv,ndev = <0x00000035>;
      riscv,max-priority = <0x00000007>;
      reg-names = "control";
      reg = <0x00000000 0x0c000000 0x00000000 0x04000000>;
      interrupts-extended = <0x00000001 0x0000000b 0x00000001 0x00000009>;
      interrupt-controller;
      compatible = "riscv,plic0";
      #interrupt-cells = <0x00000001>;
      #address-cells = <0x00000000>;
    }
    clint@2000000 {
      interrupts-extended = <0x00000001 0x00000003 0x00000001 0x00000007>;
      reg = <0x00000000 0x02000000 0x00000000 0x00010000>;
      compatible = "riscv,clint0";
    }
  }
}
[    0.000000] HART = 0 DTB = 80e00000
[    0.000000] search "chosen", depth: 0, uname:
[    0.000000] search "chosen", depth: 1, uname: chosen
[    0.000000] Looking for initrd properties...
[    0.000000] initrd_start=0x88000000  initrd_end=0x88442b86
[    0.000000] Command line is: earlyprintk
[    0.000000] dt_root_size_cells = 2
[    0.000000] dt_root_addr_cells = 2
[    0.000000] memory scan node memory@80000000, reg size 16,
[    0.000000]  - 80000000 ,  40000000
[    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80200000
[    0.000000] Linux version 4.19.0-sifive-1+ (trosinenko@trosinenko-pc) (gcc version 8.3.0 (Buildroot 2019.02-07449-g4eddd28f99)) #1 SMP Sat Jul 6 12:14:41 MSK 2019
[    0.000000] bootconsole [early0] enabled
[    0.000000] Initial ramdisk at: 0x(____ptrval____) (4467590 bytes)
[    0.000000] Zone ranges:
[    0.000000]   DMA32    [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000]   Normal   [mem 0x00000000c0000000-0x00000bffffffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000] INITIAL: ffffffe000c00000
[    0.000000]  -> unflatten_device_tree()
[    0.000000] Unflattening device tree:
[    0.000000] magic: d00dfeed
[    0.000000] size: 00000d56
[    0.000000] version: 00000011
[    0.000000]   size is 14192, allocating...
[    0.000000]   unflattening (____ptrval____)...
[    0.000000] fixed up name for  ->
[    0.000000] fixed up name for chosen -> chosen
[    0.000000] fixed up name for uart@10000000 -> uart
[    0.000000] fixed up name for test@100000 -> test
[    0.000000] fixed up name for virtio_mmio@10008000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10007000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10006000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10005000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10004000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10003000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10002000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10001000 -> virtio_mmio
[    0.000000] fixed up name for cpus -> cpus
[    0.000000] fixed up name for cpu@0 -> cpu
[    0.000000] fixed up name for interrupt-controller -> interrupt-controller
[    0.000000] fixed up name for memory@80000000 -> memory
[    0.000000] fixed up name for soc -> soc
[    0.000000] fixed up name for pci@30000000 -> pci
[    0.000000] fixed up name for interrupt-controller@c000000 -> interrupt-controller
[    0.000000] fixed up name for clint@2000000 -> clint
[    0.000000]  <- unflatten_device_tree()
[    0.000000] software IO TLB: mapped [mem 0xbb1fc000-0xbf1fc000] (64MB)
[    0.000000] 0 ffffffe03effc808 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effca78 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effcd98 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd068 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd230 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd4b8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd740 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd9c8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effdc50 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effded8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe160 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe3e8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe670 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe888 [cpu] | [cpu]
[    0.000000] ffffffe03effe888 ffffffe03effec00 [<NULL>] | [cpu]
[    0.000000] ffffffe03effe888 ffffffe03effeee8 [memory] | [cpu]
[    0.000000] ffffffe03effe888 ffffffe03efff0b0 [<NULL>] | [cpu]
[    0.000000] ffffffe03effe888 ffffffe03efff320 [pci] | [cpu]
[    0.000000] ffffffe03effe888 ffffffe03efff858 [<NULL>] | [cpu]
[    0.000000] ffffffe03effe888 ffffffe03efffd58 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effc808 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effca78 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effcd98 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd068 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd230 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd4b8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd740 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd9c8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effdc50 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effded8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe160 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe3e8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe670 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe888 [cpu] | [cpu]
[    0.000000] elf_hwcap is 0x112d
[    0.000000] percpu: Embedded 17 pages/cpu @(____ptrval____) s29400 r8192 d32040 u69632
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 258055
[    0.000000] Kernel command line: earlyprintk
[    0.000000] Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes)
[    0.000000] Inode-cache hash table entries: 65536 (order: 7, 524288 bytes)
[    0.000000] Sorting __ex_table...
[    0.000000] Memory: 949716K/1046528K available (6565K kernel code, 342K rwdata, 2564K rodata, 208K init, 832K bss, 96812K reserved, 0K cma-reserved)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.000000] rcu: Hierarchical RCU implementation.
[    0.000000] rcu:     RCU event tracing is enabled.
[    0.000000] rcu:     RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=1.
[    0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
[    0.000000] NR_IRQS: 0, nr_irqs: 0, preallocated irqs: 0
[    0.000000] plic: mapped 53 interrupts to 2 (out of 2) handlers.
[    0.000000] clocksource: riscv_clocksource: mask: 0xffffffffffffffff max_cycles: 0x24e6a1710, max_idle_ns: 440795202120 ns
[    0.000000] Console: colour dummy device 80x25
[    0.000000] console [tty0] enabled
[    0.000000] bootconsole [early0] disabled
[    0.000000] HART = 0 DTB = 80e00000
[    0.000000] search "chosen", depth: 0, uname:
[    0.000000] search "chosen", depth: 1, uname: chosen
[    0.000000] Looking for initrd properties...
[    0.000000] initrd_start=0x88000000  initrd_end=0x88442b86
[    0.000000] Command line is: earlyprintk
[    0.000000] dt_root_size_cells = 2
[    0.000000] dt_root_addr_cells = 2
[    0.000000] memory scan node memory@80000000, reg size 16,
[    0.000000]  - 80000000 ,  40000000
[    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80200000
[    0.000000] Linux version 4.19.0-sifive-1+ (trosinenko@trosinenko-pc) (gcc version 8.3.0 (Buildroot 2019.02-07449-g4eddd28f99)) #1 SMP Sat Jul 6 12:14:41 MSK 2019
[    0.000000] bootconsole [early0] enabled
[    0.000000] Initial ramdisk at: 0x(____ptrval____) (4467590 bytes)
[    0.000000] Zone ranges:
[    0.000000]   DMA32    [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000]   Normal   [mem 0x00000000c0000000-0x00000bffffffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000] INITIAL: ffffffe000c00000
[    0.000000]  -> unflatten_device_tree()
[    0.000000] Unflattening device tree:
[    0.000000] magic: d00dfeed
[    0.000000] size: 00000d56
[    0.000000] version: 00000011
[    0.000000]   size is 14192, allocating...
[    0.000000]   unflattening (____ptrval____)...
[    0.000000] fixed up name for  ->
[    0.000000] fixed up name for chosen -> chosen
[    0.000000] fixed up name for uart@10000000 -> uart
[    0.000000] fixed up name for test@100000 -> test
[    0.000000] fixed up name for virtio_mmio@10008000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10007000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10006000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10005000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10004000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10003000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10002000 -> virtio_mmio
[    0.000000] fixed up name for virtio_mmio@10001000 -> virtio_mmio
[    0.000000] fixed up name for cpus -> cpus
[    0.000000] fixed up name for cpu@0 -> cpu
[    0.000000] fixed up name for interrupt-controller -> interrupt-controller
[    0.000000] fixed up name for memory@80000000 -> memory
[    0.000000] fixed up name for soc -> soc
[    0.000000] fixed up name for pci@30000000 -> pci
[    0.000000] fixed up name for interrupt-controller@c000000 -> interrupt-controller
[    0.000000] fixed up name for clint@2000000 -> clint
[    0.000000]  <- unflatten_device_tree()
[    0.000000] software IO TLB: mapped [mem 0xbb1fc000-0xbf1fc000] (64MB)
[    0.000000] 0 ffffffe03effc808 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effca78 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effcd98 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd068 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd230 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd4b8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd740 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd9c8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effdc50 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effded8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe160 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe3e8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe670 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe888 [cpu] | [cpu]
[    0.000000] ffffffe03effe888 ffffffe03effec00 [<NULL>] | [cpu]
[    0.000000] ffffffe03effe888 ffffffe03effeee8 [memory] | [cpu]
[    0.000000] ffffffe03effe888 ffffffe03efff0b0 [<NULL>] | [cpu]
[    0.000000] ffffffe03effe888 ffffffe03efff320 [pci] | [cpu]
[    0.000000] ffffffe03effe888 ffffffe03efff858 [<NULL>] | [cpu]
[    0.000000] ffffffe03effe888 ffffffe03efffd58 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effc808 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effca78 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effcd98 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd068 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd230 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd4b8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd740 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effd9c8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effdc50 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effded8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe160 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe3e8 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe670 [<NULL>] | [cpu]
[    0.000000] 0 ffffffe03effe888 [cpu] | [cpu]
[    0.000000] elf_hwcap is 0x112d
[    0.000000] percpu: Embedded 17 pages/cpu @(____ptrval____) s29400 r8192 d32040 u69632
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 258055
[    0.000000] Kernel command line: earlyprintk
[    0.000000] Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes)
[    0.000000] Inode-cache hash table entries: 65536 (order: 7, 524288 bytes)
[    0.000000] Sorting __ex_table...
[    0.000000] Memory: 949716K/1046528K available (6565K kernel code, 342K rwdata, 2564K rodata, 208K init, 832K bss, 96812K reserved, 0K cma-reserved)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.000000] rcu: Hierarchical RCU implementation.
[    0.000000] rcu:     RCU event tracing is enabled.
[    0.000000] rcu:     RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=1.
[    0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
[    0.000000] NR_IRQS: 0, nr_irqs: 0, preallocated irqs: 0
[    0.000000] plic: mapped 53 interrupts to 2 (out of 2) handlers.
[    0.000000] clocksource: riscv_clocksource: mask: 0xffffffffffffffff max_cycles: 0x24e6a1710, max_idle_ns: 440795202120 ns
[    0.000000] Console: colour dummy device 80x25
[    0.000000] console [tty0] enabled
[    0.000000] bootconsole [early0] disabled
[    0.000000] Calibrating delay loop (skipped), value calculated using timer frequency.. 20.00 BogoMIPS (lpj=100000)
[    0.000000] pid_max: default: 32768 minimum: 301
[    0.000000] Mount-cache hash table entries: 2048 (order: 2, 16384 bytes)
[    0.000000] Mountpoint-cache hash table entries: 2048 (order: 2, 16384 bytes)
[    0.020000] rcu: Hierarchical SRCU implementation.
[    0.020000] smp: Bringing up secondary CPUs ...
[    0.020000] smp: Brought up 1 node, 1 CPU
[    0.050000] devtmpfs: initialized
[    0.050000] 0 ffffffe03effc808 [<NULL>] | [cpu]
[    0.050000] 0 ffffffe03effca78 [<NULL>] | [cpu]
[    0.050000] 0 ffffffe03effcd98 [<NULL>] | [cpu]
[    0.050000] 0 ffffffe03effd068 [<NULL>] | [cpu]
[    0.050000] 0 ffffffe03effd230 [<NULL>] | [cpu]
[    0.050000] 0 ffffffe03effd4b8 [<NULL>] | [cpu]
[    0.050000] 0 ffffffe03effd740 [<NULL>] | [cpu]
[    0.050000] 0 ffffffe03effd9c8 [<NULL>] | [cpu]
[    0.050000] 0 ffffffe03effdc50 [<NULL>] | [cpu]
[    0.050000] 0 ffffffe03effded8 [<NULL>] | [cpu]
[    0.050000] 0 ffffffe03effe160 [<NULL>] | [cpu]
[    0.050000] 0 ffffffe03effe3e8 [<NULL>] | [cpu]
[    0.050000] 0 ffffffe03effe670 [<NULL>] | [cpu]
[    0.050000] 0 ffffffe03effe888 [cpu] | [cpu]
[    0.050000] random: get_random_u32 called from bucket_table_alloc+0x76/0x17a with crng_init=0
[    0.050000] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[    0.050000] futex hash table entries: 256 (order: 2, 16384 bytes)
[    0.060000] NET: Registered protocol family 16
[    0.090000] vgaarb: loaded
[    0.090000] SCSI subsystem initialized
[    0.090000] usbcore: registered new interface driver usbfs
[    0.090000] usbcore: registered new interface driver hub
[    0.090000] usbcore: registered new device driver usb
[    0.090000] pps_core: LinuxPPS API ver. 1 registered
[    0.090000] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@linux.it>
[    0.090000] PTP clock support registered
[    0.100000] Advanced Linux Sound Architecture Driver Initialized.
[    0.100000] clocksource: Switched to clocksource riscv_clocksource
[    0.110000] NET: Registered protocol family 2
[    0.110000] tcp_listen_portaddr_hash hash table entries: 512 (order: 1, 8192 bytes)
[    0.110000] TCP established hash table entries: 8192 (order: 4, 65536 bytes)
[    0.110000] TCP bind hash table entries: 8192 (order: 5, 131072 bytes)
[    0.110000] TCP: Hash tables configured (established 8192 bind 8192)
[    0.110000] UDP hash table entries: 512 (order: 2, 16384 bytes)
[    0.110000] UDP-Lite hash table entries: 512 (order: 2, 16384 bytes)
[    0.110000] NET: Registered protocol family 1
[    0.120000] Unpacking initramfs...
[    0.590000] workingset: timestamp_bits=62 max_order=18 bucket_order=0
[    0.620000] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 251)
[    0.620000] io scheduler noop registered
[    0.620000] io scheduler deadline registered
[    0.620000] io scheduler cfq registered (default)
[    0.620000] io scheduler mq-deadline registered
[    0.620000] io scheduler kyber registered
[    0.620000] shpchp: Standard Hot Plug PCI Controller Driver version: 0.4
[    0.690000] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
[    0.690000] 10000000.uart: ttyS0 at MMIO 0x10000000 (irq = 10, base_baud = 230400) is a 16550A
[    0.720000] console [ttyS0] enabled
[    0.720000] [drm] radeon kernel modesetting enabled.
[    0.720000] [drm] amdgpu kernel modesetting enabled.
[    0.730000] loop: module loaded
[    0.730000] libphy: Fixed MDIO Bus: probed
[    0.740000] e1000e: Intel(R) PRO/1000 Network Driver - 3.2.6-k
[    0.740000] e1000e: Copyright(c) 1999 - 2015 Intel Corporation.
[    0.740000] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[    0.740000] ehci-pci: EHCI PCI platform driver
[    0.740000] ehci-platform: EHCI generic platform driver
[    0.740000] mousedev: PS/2 mouse device common for all mice
[    0.740000] usbcore: registered new interface driver usbhid
[    0.740000] usbhid: USB HID core driver
[    0.740000] usbcore: registered new interface driver snd-usb-audio
[    0.740000] NET: Registered protocol family 10
[    0.750000] Segment Routing with IPv6
[    0.750000] sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
[    0.750000] NET: Registered protocol family 17
[    0.750000] Key type dns_resolver registered
[    0.760000] ALSA device list:
[    0.760000]   No soundcards found.
[    0.770000] Freeing unused kernel memory: 208K
[    0.770000] This architecture does not have kernel memory protection.
[    0.770000] Run /init as init process

(„Časovo označené“ riadky vydáva jadro, pred nimi strom vypisuje BBL) Na jednej strane sa FDT úspešne načíta, na druhej strane sa získa nejaký nezmysel v analyzovanom „ objektový“ strom.

Počas procesu ladenia som si uvedomil, že BBL nedokáže prečítať „dvojitú“ adresu, nie preto, že by sa vyskytla chyba v konfigurácii, ale jednoducho preto, že koreňový uzol mal #address-cells = <1>; #size-cells = <1>;.

Po rozšírení výstupu ladenia som videl, že ukazuje na type и name „porazený“ a dosť zvláštnym spôsobom: ich prvý bajt (začínajúci od nuly) bol vynulovaný, niečo ako 0xabcdef -> 0xab00ef. Musel som použiť známu taktiku: poznať adresy, kde sa nachádza poškodená pamäť, pridať ju do funkcie printk vytlačte tieto údaje. No samé výzvy printk rozsyp ich tam, kde ich je málo. Bohužiaľ, nie je to oveľa jasnejšie. Potom som začal a konzultoval rozobrané objdump verzie, manuálne nastavte body prerušenia a prejdite si problematickú časť kódu krok za krokom. A potom sa zistila záhadná a nepríjemná vec: ak okamžite nastavím bod zlomu niekde relatívne ďaleko od známeho dobrého stavu, potom, keď sa pri ňom zastavím, uvidím už poškodenú pamäť. Ale ak sa k nej pokúsite krok za krokom potichu priplížiť, chrobáčik sa dokáže skryť! Zapácha to ako pokazený pamäťový radič a vyrovnávacia pamäť, ktorá skryje chybu, ak neustále požadujete požadovanú hodnotu. Čo ak…

Výmena pamäte

Držal som sa možnosti vyriešiť problém na niekom inom a predpokladal som, že som jednoducho dostal chybný pamäťový modul. Potom som si spomenul, že desaťročný netbook nie je len prenosný počítač, ale aj cenný zdroj pamäte DDR2 SO-DIMM. Ako bonus doň môžete vložiť pamäť vybratú z dosky a Memtest takmer okamžite zamrzne (LinuxMimochodom, načítalo sa to takmer až po grafický shell. Ak si však ceníte informácie na pripojených diskoch, je lepšie tento experiment neopakovať...). Na jednej strane môžeme predpokladať, že práve tomuto netbooku pamäť jednoducho nevyhovovala. Na druhej strane, dokázal naštartovať! Bola tu nádej, že pamäť bola jednoducho „zlomená“ a problém nebol v mojom obale.

To znamená, že sa musíte pokúsiť dočasne spustiť s pamäťou netbooku. Bohužiaľ, Quartus 18 nevie, ako upgradovať toto IP Core, aby ho bolo možné upravovať. To znamená, že konečne nastal čas naučiť sa vytvárať nové inštancie. Všetko sa ukázalo byť celkom jednoduché: v katalógu IP hľadáme položku DDR2 SDRAM Controller s ALTMEMPHY Intel FPGA IP a dostaneme blok s rovnakým rozhraním ako predtým. Jediným problémom je nastavenie správneho nastavenia pamäte.

Získanie parametrov pamäťového modulu

Existuje pomerne zrejmý spôsob konfigurácie modulu: prečítajte si parametre z SPD. Skutočne, ak obyčajný počítač číta údaje SPD a na ich základe konfiguruje ovládač, potom tieto údaje odčítajme na existujúcom netbooku a zadajte ich do tabuľky.

Na Ubuntu toto sa robí veľmi jednoduché: musíte nainštalovať balík i2c-tools, načítať moduly eeprom и i2c-i801 (Nie som si však istý, či druhý ovládač bude fungovať všade), potom bežte decode-dimms:

výstup decode-dimms

# decode-dimms version 6231 (2014-02-20 10:54:34 +0100)

Memory Serial Presence Detect Decoder
By Philip Edelbrock, Christian Zuckschwerdt, Burkart Lingner,
Jean Delvare, Trent Piepho and others

Decoding EEPROM: /sys/bus/i2c/drivers/eeprom/0-0050
Guessing DIMM is in                             bank 1

---=== SPD EEPROM Information ===---
EEPROM Checksum of bytes 0-62                   OK (0x00)
SPD Revision                                    Invalid
Fundamental Memory type                         Unknown (0x00)

---=== Manufacturing Information ===---
Manufacturer                                    Undefined
Part Number                                     Undefined

Decoding EEPROM: /sys/bus/i2c/drivers/eeprom/4-0050
Guessing DIMM is in                             bank 1

---=== SPD EEPROM Information ===---
EEPROM Checksum of bytes 0-62                   OK (0x00)
SPD Revision                                    Invalid
Fundamental Memory type                         Unknown (0x00)

---=== Manufacturing Information ===---
Manufacturer                                    Undefined
Part Number                                     Undefined

Decoding EEPROM: /sys/bus/i2c/drivers/eeprom/6-0050
Guessing DIMM is in                             bank 1

---=== SPD EEPROM Information ===---
EEPROM Checksum of bytes 0-62                   OK (0x76)
# of bytes written to SDRAM EEPROM              128
Total number of bytes in EEPROM                 256
Fundamental Memory type                         DDR2 SDRAM
SPD Revision                                    1.2

---=== Memory Characteristics ===---
Maximum module speed                            800 MHz (PC2-6400)
Size                                            1024 MB
Banks x Rows x Columns x Bits                   8 x 13 x 10 x 64
Ranks                                           2
SDRAM Device Width                              16 bits
Module Height                                   30.0 mm
Module Type                                     SO-DIMM (67.6 mm)
DRAM Package                                    Planar
Voltage Interface Level                         SSTL 1.8V
Module Configuration Type                       No Parity
Refresh Rate                                    Reduced (7.8 us) - Self Refresh
Supported Burst Lengths                         4, 8
tCL-tRCD-tRP-tRAS                               6-6-6-18
Supported CAS Latencies (tCL)                   6T, 5T, 4T
Minimum Cycle Time                              2.50 ns at CAS 6 (tCK min)
                                                3.00 ns at CAS 5
                                                3.75 ns at CAS 4
Maximum Access Time                             0.40 ns at CAS 6 (tAC)
                                                0.45 ns at CAS 5
                                                0.50 ns at CAS 4
Maximum Cycle Time (tCK max)                    8.00 ns

---=== Timing Parameters ===---
Address/Command Setup Time Before Clock (tIS)   0.17 ns
Address/Command Hold Time After Clock (tIH)     0.25 ns
Data Input Setup Time Before Strobe (tDS)       0.05 ns
Data Input Hold Time After Strobe (tDH)         0.12 ns
Minimum Row Precharge Delay (tRP)               15.00 ns
Minimum Row Active to Row Active Delay (tRRD)   10.00 ns
Minimum RAS# to CAS# Delay (tRCD)               15.00 ns
Minimum RAS# Pulse Width (tRAS)                 45.00 ns
Write Recovery Time (tWR)                       15.00 ns
Minimum Write to Read CMD Delay (tWTR)          7.50 ns
Minimum Read to Pre-charge CMD Delay (tRTP)     7.50 ns
Minimum Active to Auto-refresh Delay (tRC)      60.00 ns
Minimum Recovery Delay (tRFC)                   127.50 ns
Maximum DQS to DQ Skew (tDQSQ)                  0.20 ns
Maximum Read Data Hold Skew (tQHS)              0.30 ns

---=== Manufacturing Information ===---
Manufacturer                                    Samsung
Manufacturing Location Code                     0x02
Part Number                                     M4 70T2864QZ3-CF7
Revision Code                                   0x3351
Manufacturing Date                              2009-W34
Assembly Serial Number                          0x79C64E9A

Number of SDRAM DIMMs detected and decoded: 3

Problém je v tom, že niektoré časovania tu nie sú uvedené, takže poďme na druhú cestu.

Čo je napísané v našich moduloch:

Časť 4: Spustime to aj tak Linux na RocketChip RISC-VČasť 4: Spustime to aj tak Linux na RocketChip RISC-V

V tomto prípade je zaujímavejší nápis na samotných pamäťových čipoch: K4T1G164QQ-HCF7. Zadaním tohto riadku do Google získame datasheet niekoľkých desiatok stránok so všetkými potrebnými parametrami, ktoré je možné prehľadne zaradiť do vlastností IP Core. Len pozor na merné jednotky: niekde ns, niekde - psa niekedy aj zdieľania tCK. Nebudem vás učiť, na čo si dávať pozor - veľa vecí som si náhodne nakonfiguroval sám (nemôžem zaručiť, že takto nemôžete „napáliť“ pamäť alebo FPGA). Dám vám do pozornosti len toto: veľmi dlho sa mi nepodarilo sfunkčniť ovládač a posledným krokom bolo zistenie, že potrebujem skontrolovať šírku všetkých pamäťových rozhraní, či sú v súlade s vygenerovaným kódom Verilog : veď keď v MemIfBundle uvedené val mem_ba = IO(Output(UInt(2.W)))a existuje 8 bánk (t. j. adresa široká 3 bity), potom nám zostáva len výstup z pamäťového radiča visiaci vo vzduchu - problém, ale nie kritický, takže všetko je syntetizované, ale nefunguje.

Možno by všetko fungovalo so starým modulom, ak by bol ovládač aktualizovaný, ale zatiaľ som príliš lenivý na to, aby som sa vysporiadal s potenciálnymi plávajúcimi chybami: mám dosť vlastných.

Takže po presťahovaní timebase-frequency v DTS zo špecifickej úrovne CPU na úroveň uzla cpus (podľa celkom pochopiteľnej požiadavky jadra) dostaneme:

Skrytý text

[    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80200000
[    0.000000] Linux version 4.19.0-sifive-1+ (trosinenko@trosinenko-pc) (gcc version 8.3.0 (Buildroot 2019.02-07449-g4eddd28f99)) #1 SMP Tue Jul 9 22:42:36 MSK 2019
[    0.000000] bootconsole [early0] enabled
[    0.000000] Initial ramdisk at: 0x(____ptrval____) (16777216 bytes)
[    0.000000] Zone ranges:
[    0.000000]   DMA32    [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000]   Normal   [mem 0x00000000c0000000-0x00000bffffffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000080200000-0x00000000bfffffff]
[    0.000000] software IO TLB: mapped [mem 0xbb1fc000-0xbf1fc000] (64MB)
[    0.000000] elf_hwcap is 0x112d
[    0.000000] percpu: Embedded 17 pages/cpu @(____ptrval____) s29400 r8192 d32040 u69632
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 258055
[    0.000000] Kernel command line: debug console=ttySIF0,125200 root=/dev/mmcblk0p2 loglevel=7 rootwait
[    0.000000] Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes)
[    0.000000] Inode-cache hash table entries: 65536 (order: 7, 524288 bytes)
[    0.000000] Sorting __ex_table...
[    0.000000] Memory: 937696K/1046528K available (6565K kernel code, 343K rwdata, 2564K rodata, 208K init, 832K bss, 108832K reserved, 0K cma-reserved)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.000000] rcu: Hierarchical RCU implementation.
[    0.000000] rcu:     RCU event tracing is enabled.
[    0.000000] rcu:     RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=1.
[    0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
[    0.000000] NR_IRQS: 0, nr_irqs: 0, preallocated irqs: 0
[    0.000000] plic: mapped 8 interrupts to 1 (out of 2) handlers.
[    0.000000] clocksource: riscv_clocksource: mask: 0xffffffffffffffff max_cycles: 0x1d854df40, max_idle_ns: 3526361616960 ns
[    0.000000] Console: colour dummy device 80x25
[    0.000000] Calibrating delay loop (skipped), value calculated using timer frequency.. 2.00 BogoMIPS (lpj=10000)
[    0.020000] pid_max: default: 32768 minimum: 301
[    0.030000] Mount-cache hash table entries: 2048 (order: 2, 16384 bytes)
[    0.040000] Mountpoint-cache hash table entries: 2048 (order: 2, 16384 bytes)
[    0.140000] rcu: Hierarchical SRCU implementation.
[    0.190000] smp: Bringing up secondary CPUs ...
[    0.190000] smp: Brought up 1 node, 1 CPU
[    0.220000] devtmpfs: initialized
[    0.300000] random: get_random_u32 called from bucket_table_alloc+0x76/0x17a with crng_init=0
[    0.330000] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[    0.340000] futex hash table entries: 256 (order: 2, 16384 bytes)
[    0.380000] NET: Registered protocol family 16
[    1.850000] vgaarb: loaded
[    1.870000] SCSI subsystem initialized
[    1.900000] usbcore: registered new interface driver usbfs
[    1.910000] usbcore: registered new interface driver hub
[    1.920000] usbcore: registered new device driver usb
[    1.930000] pps_core: LinuxPPS API ver. 1 registered
[    1.940000] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@linux.it>
[    1.950000] PTP clock support registered
[    1.970000] Advanced Linux Sound Architecture Driver Initialized.
[    2.010000] clocksource: Switched to clocksource riscv_clocksource
[    2.600000] NET: Registered protocol family 2
[    2.640000] tcp_listen_portaddr_hash hash table entries: 512 (order: 1, 8192 bytes)
[    2.650000] TCP established hash table entries: 8192 (order: 4, 65536 bytes)
[    2.670000] TCP bind hash table entries: 8192 (order: 5, 131072 bytes)
[    2.700000] TCP: Hash tables configured (established 8192 bind 8192)
[    2.720000] UDP hash table entries: 512 (order: 2, 16384 bytes)
[    2.730000] UDP-Lite hash table entries: 512 (order: 2, 16384 bytes)
[    2.750000] NET: Registered protocol family 1
[    2.770000] Unpacking initramfs...
[   23.980000] Initramfs unpacking failed: junk in compressed archive
[   24.030000] workingset: timestamp_bits=62 max_order=18 bucket_order=0
[   25.020000] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 251)
[   25.030000] io scheduler noop registered
[   25.040000] io scheduler deadline registered
[   25.050000] io scheduler cfq registered (default)
[   25.060000] io scheduler mq-deadline registered
[   25.060000] io scheduler kyber registered
[   25.120000] sifive_gpio 64002000.gpio: SiFive GPIO chip registered 6 GPIOs
[   25.150000] shpchp: Standard Hot Plug PCI Controller Driver version: 0.4
[   28.870000] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
[   28.940000] sifive-serial 64000000.serial: unable to find controller clock
[   28.950000] sifive-serial: probe of 64000000.serial failed with error -2
[   28.980000] [drm] radeon kernel modesetting enabled.
[   28.990000] [drm] amdgpu kernel modesetting enabled.
[   29.500000] loop: module loaded
[   29.610000] sifive_spi 64001000.spi: Unable to find bus clock
[   29.620000] sifive_spi: probe of 64001000.spi failed with error -2
[   29.640000] libphy: Fixed MDIO Bus: probed
[   29.680000] e1000e: Intel(R) PRO/1000 Network Driver - 3.2.6-k
[   29.690000] e1000e: Copyright(c) 1999 - 2015 Intel Corporation.
[   29.700000] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[   29.710000] ehci-pci: EHCI PCI platform driver
[   29.720000] ehci-platform: EHCI generic platform driver
[   29.750000] mousedev: PS/2 mouse device common for all mice
[   29.790000] usbcore: registered new interface driver usbhid
[   29.800000] usbhid: USB HID core driver
[   29.820000] usbcore: registered new interface driver snd-usb-audio
[   29.900000] NET: Registered protocol family 10
[   29.960000] Segment Routing with IPv6
[   29.960000] sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
[   30.020000] NET: Registered protocol family 17
[   30.020000] Key type dns_resolver registered
[   30.070000] bootconsole [early0] uses init memory and must be disabled even before the real one is ready
[   30.080000] bootconsole [early0] disabled

Potom sa už nič viditeľné nestane.

Teraz sa môžete pokúsiť vyriešiť tri problémy:

[   23.980000] Initramfs unpacking failed: junk in compressed archive
...
[   28.940000] sifive-serial 64000000.serial: unable to find controller clock
...
[   29.610000] sifive_spi 64001000.spi: Unable to find bus clock

...a tiež zastaví výstup do konzoly.

Nie je vôbec ťažké prekonať dva problémy s frekvenciami: musíte pridať body clocks do podstromov požadovaných zariadení, pre uľahčenie uvedenia jasného názvu označenia uzla tlclk:

diff --git a/arch/riscv/dts/zeowaa-1gb.dts b/arch/riscv/dts/zeowaa-1gb.dts
index 4b2cebc..1347e76 100644
--- a/arch/riscv/dts/zeowaa-1gb.dts
+++ b/arch/riscv/dts/zeowaa-1gb.dts
@@ -96,6 +97,7 @@
                 L8: serial@64000000 {
                         compatible = "sifive,uart0";
                         interrupt-parent = <&L0>;
+                        clocks = <&tlclk>;
                         interrupts = <2>;
                         reg = <0x64000000 0x1000>;
                         reg-names = "control";
@@ -107,6 +109,7 @@
                         interrupt-parent = <&L0>;
                         interrupts = <1>;
                         reg = <0x64001000 0x1000>;
+                        clocks = <&tlclk>;
                         reg-names = "control";
                         L12: mmc@0 {
                                 compatible = "mmc-spi-slot";
@@ -116,7 +119,7 @@
                                 voltage-ranges = <3300 3300>;
                         };
                 };
-                L11: tlclk {
+                tlclk: tlclk {
                         #clock-cells = <0>;
                         clock-frequency = <25000000>;
                         clock-output-names = "tlclk";

Pridaním riadku #define pr_debug printk na začiatok súboru init/initramfs.c, ktorý zobrazuje správu o odpadkoch namiesto initramfs, dostaneme trochu podrobnejšiu správu:

[    2.760000] Unpacking initramfs...
[    2.770000] Detected gzip compressed data
[   23.940000] Detected (null) compressed data
[   23.970000] Initramfs unpacking failed: junk in compressed archive

To znamená, že odpadky možno nie namiesto initramfs a вместе.

Dobre, niečo našiel, možno to stačí. Kam zmizla konzola? Vyhľadávanie poskytuje odkaz na problém na Github: linuxu sa nepodarilo vyvolať na doske vc707 — ukazuje sa, že samotný UART podľa vodiča nestojí ani za reč. ale oprava zo dňa 11. júla 2018 - pred rokom. Ukázalo sa, že tento commit sa nikdy nedostal do stromu, z ktorého vytváram jadro. Ručnou aplikáciou tejto opravy som získal funkčný Linux! Ukázalo sa, že problém s initramfs naozaj nebol kritický.

Prihlásenie ako user=root, password=sifive som zvládol bez problémov (až na pochopenie toho, že GPIO číslo má základ, z ktorého sa všetko počíta a ktoré stačí načítať z príslušného pseudosúboru) cez sysfs rozsvieti LED na doske.

Ako minule, prikladám textové video zo spustenia LinuxPri prepnutí konzoly z earlyprintk na štandardnú sa objaví nejaký druh odpadu, podobný výstupu z nesprávne nastavenej rýchlosti UART. Je zaujímavé, že hráč si s týmto „neporiadkom“ úspešne poradil.

Časť 4: Spustime to aj tak Linux na RocketChip RISC-V

Zdroj: hab.com

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