Dio 4: Još uvijek radi Linux na RocketChip RISC-V

Dio 4: Još uvijek radi Linux na RocketChip RISC-V Na slici vam Linux kernel šalje pozdrave putem GPIO-a.

U ovom dijelu priče o portovanju RISC-V RocketChip-a na kinesku ploču sa Cyclone IV, i dalje ćemo pokretati Linux, a također ćemo naučiti kako sami konfigurirati IP Core memorijski kontroler i malo urediti DTS opis opreme. Ovaj članak je nastavak treći dio, ali, za razliku od prilično opširnog prethodnog, bit će prilično kratak.

… Zbog setup_smp poziva samo ako je kernel konfigurisan sa podrškom za SMP, možete pokušati da onemogućite više jezgre. Biće neprijatno ako trebam da implementiram i podršku za atomičnost u memorijskom modulu (činilo mi se da se keš popravlja sam od sebe), ali u slučaju sa jednim jezgrom to ne bi trebalo da nas ometa.

Još uvek nije poleteo...

[    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
...

Zanimljivo je da sam nakon svih otklanjanja grešaka odlučio da pogledam kako bi trebao izgledati "referentni" izlaz kernela, rekao je make qemu, i vidio sličnu grešku.

Jao, sljedeći nivo (Linux kernel) je komplikovaniji: GDB, povezan preko JTAG-a na RocketChip, očigledno radi sa fizičkim adresama bez obzira na to kako je MMU konfigurisan, a kernel u ovom trenutku koji nas zanima je već konfigurirao ekran adresa, tako da je lako reći display/10i $pc neće ići - videćemo samo mnogo toga unimp. Ali ako smo već shvatili pomak (čini se da 0x80200000 -> 0xffffffe000000000), tada možete varati:

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)

Prelomne tačke se postavljaju na isti način:

(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

Ali morate ih ručno ukloniti da biste nastavili dalje - za GDB je to neka vrsta potpuno neshvatljive zamke. Oh da, ako slučajno kažeš s ili n umjesto si, gdb će pokušati da ubaci implicitnu tačku prekida, koja iz očiglednih razloga neće biti postavljena, ali ne postoji način da se odvrati GDB. Ali nemojte žuriti da ponovo pokrenete ploču - prema mojim zapažanjima, dovoljno je ponovo pokrenuti samo gdb (imajte na umu da stare tačke prekida možda neće nestati).

Zapravo, moraćete da se pozabavite prvobitnim problemom: postavljanjem debagovanja printk u funkciju of_find_node_by_type, koji koristi kod za pretragu kernela procesora za pokretanje, pokazuje da vidi neku vrstu smeća umjesto imena tipova uređaja. Na primjer, odnekud uzima liniju "Serial port", iako to očito nije u dtb polju device_type. Potraživši ove bajtove u slici kernela, pronašao sam ih, pogledao pomak i shvatio očigledno: veličina kernela u parametrima pokretanja je očigledno podcijenjena: dodijeljeno mu je 8Mb, ali zauzima više od deset. Dodijelio sam 16Mb, ali čudnost nije prestala. Nakon plesanja sa čitanjem FDT-a sa različitih adresa (obično se adresa prenosi u kernel u registru a1), konačno sam odlučio da uđem u trag, ali šta сейчас tamo je raščlanjeno. Srećom, umjesto da šetate okolo s programom za otklanjanje grešaka (a sjećamo se da postoje nijanse s prijevodom adresa koje još uvijek treba riješiti na ovaj ili onaj način), možete jednostavno i gurnuti u datoteku drivers/of/fdt.c ukazati #define pr_debug printk. Rezultat je bio:

dodavanje izlaza za otklanjanje grešaka

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);

Izlaz na hardveru

                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]

Izlaz u 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 <[email protected]>
[    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

(“Vremensko označene” linije izlaze od strane kernela, ispred njih stablo izlazi od strane BBL) S jedne strane, FDT se uspješno čita, s druge strane, dobija se neka vrsta gluposti u raščlanjenom “ objekt” drvo.

Tokom procesa otklanjanja grešaka, shvatio sam da BBL ne može pročitati „dvostruku“ adresu, ne zato što je došlo do greške u konfiguraciji, već jednostavno zato što je korijenski čvor imao #address-cells = <1>; #size-cells = <1>;.

Proširujući izlaz za otklanjanje grešaka, video sam da to ukazuje na type и name “prebijeni”, i to na prilično čudan način: njihov prvi bajt (počevši od nule) resetiran je na nulu, nešto poput 0xabcdef -> 0xab00ef. Morao sam koristiti poznatu taktiku: znajući adrese na kojima se nalazi oštećena memorija, dodajte je funkciji printk odštampati ove podatke. Pa, sami izazovi printk razbacajte ih tamo gde ih je malo. Nažalost, nije postalo mnogo jasnije. Onda sam počeo, konsultujući rastavljene objdump verziju, ručno postavite tačke prekida i prođite kroz problematični dio koda korak po korak. A onda je otkrivena misteriozna i neugodna stvar: ako odmah postavim tačku prekida negdje relativno daleko od poznatog dobrog stanja, onda ću, zaustavivši se na tome, vidjeti već oštećeno sjećanje. Ali ako pokušate da joj se tiho prišunjate korak po korak, buba se uspijeva sakriti! Smrdi na pokvareni memorijski kontroler i keš koji skriva grešku ako stalno zahtijevate potrebnu vrijednost. Šta ako…

Zamjena memorije

Držeći se prilike da riješim problem koji nije bio na mojoj strani, pretpostavio sam da sam možda upravo dobio pokvareni memorijski stick. Tada sam se sjetio da deset godina star netbook nije samo prijenosni računar, već i vrijedan izvor DDR2 SO-DIMM. Kao bonus, u njega možete staviti memoriju uklonjenu sa ploče i natjerati Memtest da visi gotovo trenutno (Linux je, inače, učitan gotovo do grafičke ljuske. Ali bolje je ne ponavljati ovaj eksperiment ako cijenite informacije na montiranim diskovima...). S jedne strane, možemo pretpostaviti da memorija jednostavno nije odgovarala ovom konkretnom netbooku. S druge strane, bio je u stanju da se diže! Postojala je nada da je pamćenje jednostavno „polomljeno“, a problem nije bio u mom omotu.

To znači da morate pokušati da se privremeno pokrenete sa netbook memorijom. Nažalost, Quartus 18 ne zna kako da nadogradi ovaj IP Core tako da se može uređivati. To znači da je konačno došlo vrijeme da naučite kako kreirati nove instance. Ispostavilo se da je sve prilično jednostavno: tražimo u IP katalogu stavku DDR2 SDRAM kontroler sa ALTMEMPHY Intel FPGA IP i dobijamo blok sa istim interfejsom kao i ranije. Jedini problem je postavljanje ispravnih postavki memorije.

Dobivanje parametara memorijskog modula

Postoji relativno očigledan način konfigurisanja modula: čitanje parametara iz SPD-a. Zaista, ako običan računar čita SPD podatke i na osnovu njih konfiguriše kontroler, onda oduzmemo ove podatke na postojećem netbook-u i unesemo ih u tabelu.

Ovo se radi na Ubuntu veoma jednostavno: potrebno je da instalirate paket i2c-tools, učitavanje modula eeprom и i2c-i801 (Nisam siguran, međutim, da će drugi drajver raditi svuda), a zatim pokrenite decode-dimms:

Dekodiranje-zatamnjivanje izlaza

# 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

Problem je što neki tajmingi nisu naznačeni ovdje, pa idemo drugim putem.

Šta piše na našim modulima:

Dio 4: Još uvijek radi Linux na RocketChip RISC-VDio 4: Još uvijek radi Linux na RocketChip RISC-V

U ovom slučaju, zanimljiviji je natpis na samim memorijskim čipovima: K4T1G164QQ-HCF7. Upisivanjem ovog reda u Google, dobijamo datasheet od nekoliko desetina stranica sa svim potrebnim parametrima, koji se mogu uredno uključiti u svojstva IP Core. Samo obratite pažnju na mjerne jedinice: negdje ns, negde - ps, a ponekad čak i dionice tCK. Neću vas učiti na šta da obratite pažnju - dosta sam stvari sam konfigurisao nasumično (ne mogu garantovati da ne možete "spaliti" memoriju ili FPGA na ovaj način). Samo ću vam skrenuti pažnju na ovo: nisam mogao da natjeram kontroler da radi jako dugo, a posljednji korak je bila spoznaja da moram provjeriti širinu svih memorijskih sučelja radi usklađenosti sa generiranim Verilog kodom : na kraju krajeva, kada uđe MemIfBundle naznačeno val mem_ba = IO(Output(UInt(2.W))), a ima 8 banaka (tj. adresa širine 3 bita), onda imamo samo izlaz iz memorijskog kontrolera koji visi u zraku - problem, ali nije kritičan, tako da je sve sintetizirano, ali ne radi.

Možda bi sve funkcionisalo sa starim modulom da je kontroler ažuriran, ali za sada sam previše lijen da se bavim potencijalnim plutajućim greškama: imam dovoljno svojih.

Dakle, nakon preseljenja timebase-frequency u DTS-u od specifičnog nivoa procesora do nivoa čvora cpus (prema sasvim razumljivom zahtjevu kernela), dobijamo:

Skriveni tekst

[    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 <[email protected]>
[    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

Nakon čega se ništa vidljivo ne dešava.

Sada možete pokušati riješiti tri problema:

[   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

...i također zaustavlja izlaz na konzolu.

Uopće nije teško prevladati dva problema s frekvencijama: trebate dodati bodove clocks u podstabla potrebnih uređaja, radi praktičnosti dajući jasno ime oznake za čvor 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";

Dodavanjem linije #define pr_debug printk na početak datoteke init/initramfs.c, koji prikazuje poruku o smeću umjesto initramfs-a, dobijamo malo detaljniju poruku:

[    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

Odnosno, možda smeće nije umjesto initramfs, i вместе.

Dobro, našao je nešto, možda je to dovoljno. Gdje je nestala konzola? Pretraga daje vezu do problema na Githubu: linux nije uspio da se pokrene na vc707 ploči — ispostavilo se da sam UART, prema vozaču, nije vrijedan ni govora. Ali korekcija od 11. jula 2018. - prije godinu dana. Ispostavilo se da ovaj urez nikada nije stigao do stabla od kojeg pravim kernel. Ručnim primjenom ove zakrpe, dobio sam Linux koji radi! Ispostavilo se da problem sa initramfs-om zaista nije kritičan.

Uloguj se kao user=root, password=sifive, uspeo sam bez problema (osim razumevanja da GPIO broj ima bazu, iz koje se sve računa i koju samo treba pročitati iz odgovarajuće pseudo-datoteke) kroz sysfs upali LED na ploči.

Kao i prošli put, prilažem tekstualni video o pokretanju Linuxa. Kada se konzola prebaci sa earlyprintk na standardni, pojavljuje se neka vrsta smeća, slično kao na izlazu kada je UART brzina pogrešno podešena. Zanimljivo je da je igrač uspješno prošao kroz ovaj "nered".

Dio 4: Još uvijek radi Linux na RocketChip RISC-V

izvor: www.habr.com