wiki:Dev/KernelHack

Version 30 (modified by mitty, 11 years ago) (diff)

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  1. tools
  2. how to build kernel
    1. (example) build 3.6.1 on Ubuntu 12.04 and install to 12.10
  3. how to enhancement kernel
  4. debugging Linux Kernel with VMware Workstation
    1. x86
    2. x64
  5. Serial Console

tools

  • ​4.3.5. Tracking Most Frequently Used System Calls
  • ​Kernel/CrashdumpRecipe - Ubuntu Wiki

    LKCD is a project that tries to enable enterprise style post-mortem crash analysis in Linux operating systems. It uses a special mode of kexec which allows to automatically boot a secondary kernel whenever a crash (Oops/panic) occurs. This secondary kernel will then save the state and memory of the primary kernel to a certain location of the filesystem (/var/crash on newer releases). This file can then be used by crash to gather detailed information about the problem.

how to build kernel

  • Ubuntuの場合、aptitude build-dep linuxでカーネルのビルドに必要なパッケージは導入される
    • 3.9.x以降をビルドする場合は、bcパッケージも必要 
        BC      kernel/timeconst.h
/bin/sh: 1: bc: not found
make[3]: *** [kernel/timeconst.h] Error 127
make[2]: *** [kernel] Error 2
  • カーネルソースを展開して、「make help」でmakeオプションが表示される

(example) build 3.6.1 on Ubuntu 12.04 and install to 12.10

  • ソースの入手
  • ビルド環境構築
    • mitty@precise:~$ sudo aptitude build-dep linux
    • mitty@precise:~/linux-3.6.1$ scp mitty@quantal64:/boot/config-3.5.0-17-generic .config
  • ビルド
    • mitty@precise:~/linux-3.6.1$ make oldconfig
      • $ make oldnoconfig -> Same as silentoldconfig but sets new symbols to their default value
    • mitty@precise:~/linux-3.6.1$ make -j9 deb-pkg
  • debパッケージのインストール
    • mitty@precise:~$ scp linux-image-3.6.1_3.6.1-3_amd64.deb mitty@quantal64:~
    • mitty@quantal64:~$ sudo dpkg -i linux-image-3.6.1_3.6.1-3_amd64.deb

how to enhancement kernel

debugging Linux Kernel with VMware Workstation

  • ​http://wiki.osdev.org/VMWare
    • Guest debugging
      • These options are valid in Workstation 6.0+, and should be set in the virtual machine's .vmx file. 
        debugStub.listen.guest32 = "TRUE"
debugStub.listen.guest64 = "TRUE"
      • If using these options, Workstation prints a message "VMware Workstation is listening for debug connection on port 8832." into the vmware.log file. Start a GDB session (using a copy of your kernel that includes debug information), then: 
        target remote localhost:8832
      • Standard gdb commands work in this mode (e.g. printing memory, backtrace). Note that this is a debug stub attached to the KERNEL, not a userspace program.
      • Other useful options: 
        debugStub.listen.guest32.remote = "TRUE" # Allows debugging from a different computer / VM instead of localhost. # The IP for remote debugging will be that of the host.
debugStub.listen.guest64.remote = "TRUE" # Same, but for 64-bit code
monitor.debugOnStartGuest32 = "TRUE" # Breaks into debug stub on first instruction (warning: in BIOS!) # This will halt the VM at the very first instruction at 0xFFFF0, you could set the next breakpoint to break *0x7c00 to break when the bootloader is loaded by the BIOS
debugStub.hideBreakpoints = "TRUE" # Allows gdb breakpoints to work
bios.bootDelay = "3000" # Delay booting the BIOS code.
  • windellはVistaとのデュアルブートなため、UTCではなくlocal timeでRTCが設定されている
    • Ubuntu インストール時に、UTCにすると時計が9時間進む

x86

x64

  • viola0[1-6]でビルドする場合、そのままではx86_64のカーネルが作られるので注意

Serial Console

  • ​http://qemu.weilnetz.de/qemu-doc.html#direct_005flinux_005fboot 3.9 Direct Linux Boot
  • ex) $ sudo qemu-system-x86_64 -m 512 -vnc :1 -kernel /boot/vmlinuz-3.5.0-45-generic -append "console=tty0 console=ttyS0,115200n8r" -serial stdio 
    qemu-system-x86_64: pci_add_option_rom: failed to find romfile "pxe-rtl8139.rom"
[    0.000000] Initializing cgroup subsys cpuset
[    0.000000] Initializing cgroup subsys cpu
[    0.000000] Linux version 3.5.0-45-generic (buildd@toyol) (gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-2ubuntu1) ) #68-Ubuntu SMP Mon Dec 2 21:58:52 UTC 2013 (Ubuntu 3.5.0-45.68-generic 3.5.7.26)
[    0.000000] Command line: console=tty0 console=ttyS0,115200n8r

(smip)
    • マニュアルにはWhen using the direct Linux boot, a disk image for the first hard disk hda is required because its boot sector is used to launch the Linux kernel.とあるが、少なくともqemu-kvm-1.2.0+noroms-0ubuntu2.12.10.6, Debianでは不要な模様