Системаи сохтани ядро маҷмӯи аст Makefiles с бисьёр асбобҳо ва скриптҳои фармоишӣ барои автоматикунонии раванд. Аввалан, барномаи танзимоти интерактивиро кушоед:
make ARCH=um menuconfig
Он барои шумо қуттии муколамаро қисман сохта ва намоиш медиҳад. Кай '[Select]', шумо метавонед бо истифода аз тугмаҳои Фосила ё Enter танзим кунед. Дар равзанаи маъмулӣ, бо тирҳои клавиатура "боло" ва "поён" ҳаракат кунед ва унсурҳоро интихоб кунед - "чап" ё "рост".
Нишондиҳандаи намоиш —> маънои онро дорад, ки шумо дар зерменю қарор доред, ки бо тугмаи Enter дастрас аст. Роҳи раҳоӣ аз он бешубҳа тавассути '[Exit]'.
UML-specific Options:
- Host filesystem
Networking support (enable this to get the submenu to show up):
- Networking options:
- TCP/IP Networking
UML Network devices:
- Virtual network device
- SLiRP transport
Ин аст, шумо метавонед аз ин равзана бо интихоби пай дар пай '[Exit]'. Танҳо боварӣ ҳосил кунед, ки дар охир аз шумо хоҳиш карда мешавад, ки конфигуратсияро захира кунед ва '-ро интихоб кунед.[Yes]'.
Ман тавсия медиҳам, ки пас аз хондани ин мақола бо имконоти сохтани ядро бозӣ кунед. Тавассути ин тачрибахо дар бобати фахмидани кори механикони ядрои дарачаи паст ва таъсири байракхои гуногун ба васлкунии он бисьёр чизхоро омухтан мумкин аст.
Сохтани ядро
Ядрои Linux як барномаи бузургест, ки корҳои зиёдеро иҷро мекунад. Ҳатто бо чунин конфигуратсияи ҳадди ақал дар сахтафзори кӯҳна, сохтани он метавонад вақти зиёдеро талаб кунад. Пас, ядроро бо фармони зерин созед:
linux --help
User Mode Linux v5.1.16
available at http://user-mode-linux.sourceforge.net/
--showconfig
Prints the config file that this UML binary was generated from.
iomem=<name>,<file>
Configure <file> as an IO memory region named <name>.
mem=<Amount of desired ram>
This controls how much "physical" memory the kernel allocates
for the system. The size is specified as a number followed by
one of 'k', 'K', 'm', 'M', which have the obvious meanings.
This is not related to the amount of memory in the host. It can
be more, and the excess, if it's ever used, will just be swapped out.
Example: mem=64M
--help
Prints this message.
debug
this flag is not needed to run gdb on UML in skas mode
root=<file containing the root fs>
This is actually used by the generic kernel in exactly the same
way as in any other kernel. If you configure a number of block
devices and want to boot off something other than ubd0, you
would use something like:
root=/dev/ubd5
--version
Prints the version number of the kernel.
umid=<name>
This is used to assign a unique identity to this UML machine and
is used for naming the pid file and management console socket.
con[0-9]*=<channel description>
Attach a console or serial line to a host channel. See
http://user-mode-linux.sourceforge.net/old/input.html for a complete
description of this switch.
eth[0-9]+=<transport>,<options>
Configure a network device.
aio=2.4
This is used to force UML to use 2.4-style AIO even when 2.6 AIO is
available. 2.4 AIO is a single thread that handles one request at a
time, synchronously. 2.6 AIO is a thread which uses the 2.6 AIO
interface to handle an arbitrary number of pending requests. 2.6 AIO
is not available in tt mode, on 2.4 hosts, or when UML is built with
/usr/include/linux/aio_abi.h not available. Many distributions don't
include aio_abi.h, so you will need to copy it from a kernel tree to
your /usr/include/linux in order to build an AIO-capable UML
nosysemu
Turns off syscall emulation patch for ptrace (SYSEMU).
SYSEMU is a performance-patch introduced by Laurent Vivier. It changes
behaviour of ptrace() and helps reduce host context switch rates.
To make it work, you need a kernel patch for your host, too.
See http://perso.wanadoo.fr/laurent.vivier/UML/ for further
information.
uml_dir=<directory>
The location to place the pid and umid files.
quiet
Turns off information messages during boot.
hostfs=<root dir>,<flags>,...
This is used to set hostfs parameters. The root directory argument
is used to confine all hostfs mounts to within the specified directory
tree on the host. If this isn't specified, then a user inside UML can
mount anything on the host that's accessible to the user that's running
it.
The only flag currently supported is 'append', which specifies that all
files opened by hostfs will be opened in append mode.
Core dump limits :
soft - 0
hard - NONE
Checking that ptrace can change system call numbers...OK
Checking syscall emulation patch for ptrace...OK
Checking advanced syscall emulation patch for ptrace...OK
Checking environment variables for a tempdir...none found
Checking if /dev/shm is on tmpfs...OK
Checking PROT_EXEC mmap in /dev/shm...OK
Adding 32137216 bytes to physical memory to account for exec-shield gap
Linux version 5.1.16 (cadey@kahless) (gcc version 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1)) #30 Sun Jul 7 18:57:19 UTC 2019
Built 1 zonelists, mobility grouping on. Total pages: 23898
Kernel command line: root=/dev/root rootflags=/home/cadey/dl/uml/alpine rootfstype=hostfs rw mem=64M init=/bin/sh
Dentry cache hash table entries: 16384 (order: 5, 131072 bytes)
Inode-cache hash table entries: 8192 (order: 4, 65536 bytes)
Memory: 59584K/96920K available (2692K kernel code, 708K rwdata, 588K rodata, 104K init, 244K bss, 37336K reserved, 0K cma-reserved)
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
NR_IRQS: 15
clocksource: timer: mask: 0xffffffffffffffff max_cycles: 0x1cd42e205, max_idle_ns: 881590404426 ns
Calibrating delay loop... 7479.29 BogoMIPS (lpj=37396480)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 512 (order: 0, 4096 bytes)
Mountpoint-cache hash table entries: 512 (order: 0, 4096 bytes)
Checking that host ptys support output SIGIO...Yes
Checking that host ptys support SIGIO on close...No, enabling workaround
devtmpfs: initialized
random: get_random_bytes called from setup_net+0x48/0x1e0 with crng_init=0
Using 2.6 host AIO
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
futex hash table entries: 256 (order: 0, 6144 bytes)
NET: Registered protocol family 16
clocksource: Switched to clocksource timer
NET: Registered protocol family 2
tcp_listen_portaddr_hash hash table entries: 256 (order: 0, 4096 bytes)
TCP established hash table entries: 1024 (order: 1, 8192 bytes)
TCP bind hash table entries: 1024 (order: 1, 8192 bytes)
TCP: Hash tables configured (established 1024 bind 1024)
UDP hash table entries: 256 (order: 1, 8192 bytes)
UDP-Lite hash table entries: 256 (order: 1, 8192 bytes)
NET: Registered protocol family 1
console [stderr0] disabled
mconsole (version 2) initialized on /home/cadey/.uml/tEwIjm/mconsole
Checking host MADV_REMOVE support...OK
workingset: timestamp_bits=62 max_order=14 bucket_order=0
Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254)
io scheduler noop registered (default)
io scheduler bfq registered
loop: module loaded
NET: Registered protocol family 17
Initialized stdio console driver
Using a channel type which is configured out of UML
setup_one_line failed for device 1 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 2 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 3 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 4 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 5 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 6 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 7 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 8 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 9 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 10 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 11 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 12 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 13 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 14 : Configuration failed
Using a channel type which is configured out of UML
setup_one_line failed for device 15 : Configuration failed
Console initialized on /dev/tty0
console [tty0] enabled
console [mc-1] enabled
Failed to initialize ubd device 0 :Couldn't determine size of device's file
VFS: Mounted root (hostfs filesystem) on device 0:11.
devtmpfs: mounted
This architecture does not have kernel memory protection.
Run /bin/sh as init process
/bin/sh: can't access tty; job control turned off
random: fast init done
/ #
Манипуляцияҳои дар боло овардашуда ба мо хоҳанд дод системаи меҳмон ҳадди ақал, бе чизҳои монанди /proc ё номи мизбони таъиншуда. Масалан, фармонҳои зеринро санҷед:
- uname -av
- cat /proc/self/pid
- hostname
Барои баромадан аз меҳмон, нависед exit ё control-d-ро пахш кунед. Ин қабатро мекушад ва пас аз он ваҳми ядро мебошад:
/ # exit
Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000000
fish: “./linux root=/dev/root rootflag…” terminated by signal SIGABRT (Abort)
Мо ин воҳимаи ядроро гирифтем, зеро ядрои Linux фикр мекунад, ки раванди оғозёбӣ ҳамеша иҷро мешавад. Бе он, система дигар кор карда наметавонад ва ба садама дучор мешавад. Аммо азбаски ин як раванди реҷаи корбар аст, натиҷаи натиҷа худ ба он мефиристад SIGABRT, ки дар натичаи он баромад.
Танзимоти шабакаи меҳмонон
Ва ин аст, ки корҳо ба хатогӣ шурӯъ мекунанд. Шабака дар режими корбар Linux дар он ҷоест, ки тамоми мафҳуми маҳдуди "режими корбар" аз ҳам ҷудо мешавад. Баъд аз ҳама, одатан дар сатҳи система, шабака маҳдуд аст имтиёздор усулҳои иҷро барои ҳамаи мо сабабҳои фаҳмо.
Шарҳ. per .: шумо метавонед бештар дар бораи имконоти гуногуни кор бо шабака дар UML хонед дар ин ҷо.
Сафар ба Слирп
Бо вуҷуди ин, як асбоби қадимӣ ва қариб дастгирӣнашаванда мавҷуд аст Слип, ки бо он Ҳолати User Linux метавонад бо шабака ҳамкорӣ кунад. Он ба мисли стеки сатҳи корбар TCP/IP кор мекунад ва барои кор кардан ягон иҷозати системаро талаб намекунад. Ин асбоб буд соли 1995 бароварда шудааст, ва навсозии охирин санаи Соли 2006. Slirp хеле кӯҳна аст. Дар тӯли муддате, ки бидуни дастгирӣ ва навсозӣ, компиляторҳо то ҳадде рафтанд, ки ҳоло ин асбобро танҳо метавон тавсиф кард пӯсидаи код.
Пас, биёед Slirp-ро аз анбори Ubuntu зеркашӣ кунем ва кӯшиш кунем, ки онро иҷро кунем:
sudo apt-get install slirp
/usr/bin/slirp
Slirp v1.0.17 (BETA)
Copyright (c) 1995,1996 Danny Gasparovski and others.
All rights reserved.
This program is copyrighted, free software.
Please read the file COPYRIGHT that came with the Slirp
package for the terms and conditions of the copyright.
IP address of Slirp host: 127.0.0.1
IP address of your DNS(s): 1.1.1.1, 10.77.0.7
Your address is 10.0.2.15
(or anything else you want)
Type five zeroes (0) to exit.
[autodetect SLIP/CSLIP, MTU 1500, MRU 1500, 115200 baud]
SLiRP Ready ...
fish: “/usr/bin/slirp” terminated by signal SIGSEGV (Address boundary error)
sudo apt-get install gdb slirp-dbgsym
gdb /usr/bin/slirp
GNU gdb (Ubuntu 8.1-0ubuntu3) 8.1.0.20180409-git
Copyright (C) 2018 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from /usr/bin/slirp...Reading symbols from /usr/lib/debug/.build-id/c6/2e75b69581a1ad85f72ac32c0d7af913d4861f.debug...done.
done.
(gdb) run
Starting program: /usr/bin/slirp
Slirp v1.0.17 (BETA)
Copyright (c) 1995,1996 Danny Gasparovski and others.
All rights reserved.
This program is copyrighted, free software.
Please read the file COPYRIGHT that came with the Slirp
package for the terms and conditions of the copyright.
IP address of Slirp host: 127.0.0.1
IP address of your DNS(s): 1.1.1.1, 10.77.0.7
Your address is 10.0.2.15
(or anything else you want)
Type five zeroes (0) to exit.
[autodetect SLIP/CSLIP, MTU 1500, MRU 1500, 115200 baud]
SLiRP Ready ...
Program received signal SIGSEGV, Segmentation fault.
ip_slowtimo () at ip_input.c:457
457 ip_input.c: No such file or directory.
(gdb) bt full
#0 ip_slowtimo () at ip_input.c:457
fp = 0x55784a40
#1 0x000055555556a57c in main_loop () at ./main.c:980
so = <optimized out>
so_next = <optimized out>
timeout = {tv_sec = 0, tv_usec = 0}
ret = 0
nfds = 0
ttyp = <optimized out>
ttyp2 = <optimized out>
best_time = <optimized out>
tmp_time = <optimized out>
#2 0x000055555555b116 in main (argc=1, argv=0x7fffffffdc58) at ./main.c:95
No locals.
Дар ин ҷо мо мебинем, ки садама ҳангоми оғози гардиши асосӣ вақте рух медиҳад, ки slirp кӯшиши санҷиши вақтро тафтиш мекунад. Дар ин лаҳза, ман маҷбур шудам, ки аз кӯшиши ислоҳ кардан даст кашам. Аммо биёед бубинем, ки оё Slirp аз навъҳо сохта шудааст, кор мекунад. Ман архивро мустақиман аз сайт дубора зеркашӣ кардам sourceforge, зеро кашидани чизе аз он ҷо тавассути сатри фармон дард аст:
cd ~/dl
wget https://xena.greedo.xeserv.us/files/slirp-1.0.16.tar.gz
tar xf slirp-1.0.16.tar.gz
cd slirp-1.0.16/src
./configure --prefix=$HOME/prefix/slirp
make
total 6136
-rwxr-xr-x 1 cadey cadey 79744 Dec 10 2017 ifconfig*
-rwxr-xr-x 1 cadey cadey 373 Dec 13 2017 init*
-rwxr-xr-x 1 cadey cadey 149688 Dec 10 2017 insmod*
-rwxr-xr-x 1 cadey cadey 66600 Dec 10 2017 route*
-rwxr-xr-x 1 cadey cadey 181056 Jun 26 2015 slirp*
-rwxr-xr-x 1 cadey cadey 5786592 Dec 15 2017 uml*
-rwxr-xr-x 1 cadey cadey 211 Dec 13 2017 uml_run*
Ин бинарии slirp аст! Оё ӯ кор мекунад?
./slirp
Slirp v1.0.17 (BETA) FULL_BOLT
Copyright (c) 1995,1996 Danny Gasparovski and others.
All rights reserved.
This program is copyrighted, free software.
Please read the file COPYRIGHT that came with the Slirp
package for the terms and conditions of the copyright.
IP address of Slirp host: 127.0.0.1
IP address of your DNS(s): 1.1.1.1, 10.77.0.7
Your address is 10.0.2.15
(or anything else you want)
Type five zeroes (0) to exit.
[autodetect SLIP/CSLIP, MTU 1500, MRU 1500]
SLiRP Ready ...