QEMU ARM で遊ぼう

#include <stdlib.h>
#include <stdio.h>

int main()
{
    printf("Hello ARM world.\n") ;
    return(0) ;
}

$ arm-linux-gnueabi-gcc hello.c -o hello

$ arm-linux-gnueabi-readelf -h hello
ELF Header:
  Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
  Class:                             ELF32
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              EXEC (Executable file)
  Machine:                           ARM
  Version:                           0x1
  Entry point address:               0x102c4
  Start of program headers:          52 (bytes into file)
  Start of section headers:          7368 (bytes into file)
  Flags:                             0x5000202, has entry point, Version5 EABI, soft-float ABI
  Size of this header:               52 (bytes)
  Size of program headers:           32 (bytes)
  Number of program headers:         8
  Size of section headers:           40 (bytes)
  Number of section headers:         37
  Section header string table index: 34

$ qemu-arm
usage: qemu-arm [options] program [arguments...]
Linux CPU emulator (compiled for arm emulation)

Options and associated environment variables:

Argument     Env-variable      Description
-h                             print this help
-g port      QEMU_GDB          wait gdb connection to 'port'
-L path      QEMU_LD_PREFIX    set the elf interpreter prefix to 'path'
-s size      QEMU_STACK_SIZE   set the stack size to 'size' bytes
-cpu model   QEMU_CPU          select CPU (-cpu help for list)
-E var=value QEMU_SET_ENV      sets targets environment variable (see below)
-U var       QEMU_UNSET_ENV    unsets targets environment variable (see below)
-0 argv0     QEMU_ARGV0        forces target process argv[0] to be 'argv0'
-r uname     QEMU_UNAME        set qemu uname release string to 'uname'
-B address   QEMU_GUEST_BASE   set guest_base address to 'address'
-R size      QEMU_RESERVED_VA  reserve 'size' bytes for guest virtual address space
-d options   QEMU_LOG          activate log
-D logfile   QEMU_LOG_FILENAME override default logfile location
-p pagesize  QEMU_PAGESIZE     set the host page size to 'pagesize'
-singlestep  QEMU_SINGLESTEP   run in singlestep mode
-strace      QEMU_STRACE       log system calls
-version     QEMU_VERSION      display version information and exit

Defaults:
QEMU_LD_PREFIX  = /usr/qemu-arm
QEMU_STACK_SIZE = 8388608 byte
QEMU_LOG        = /tmp/qemu.log

You can use -E and -U options or the QEMU_SET_ENV and
QEMU_UNSET_ENV environment variables to set and unset
environment variables for the target process.
It is possible to provide several variables by separating them
by commas in getsubopt(3) style. Additionally it is possible to
provide the -E and -U options multiple times.
The following lines are equivalent:
    -E var1=val2 -E var2=val2 -U LD_PRELOAD -U LD_DEBUG
    -E var1=val2,var2=val2 -U LD_PRELOAD,LD_DEBUG
    QEMU_SET_ENV=var1=val2,var2=val2 QEMU_UNSET_ENV=LD_PRELOAD,LD_DEBUG
Note that if you provide several changes to a single variable
the last change will stay in effect.

$ qemu-arm -L /usr/local/arm_linux/arm-linux-gnueabi ./hello
Hello ARM world.

$ cat gdbtest.c
#include <stdlib.h>
#include <stdio.h>

int main(int argc, char* argv[])
{
    int i ;
    printf("argc=%d\n",argc) ;
    for( i=0 ; i<argc ; i++ ){
        printf("%s\n",argv[i]) ;
    }
    return(0) ;
}

$ arm-linux-gnueabi-gcc -static -g gdbtest.c -o gdbtest

$ qemu-arm -g 1111 -L /usr/local/arm_linux/arm-linux-gnueabi ./gdbtest aaa bbb ccc ddd eee

$ arm-linux-gnueabi-gdb -q
(gdb) file gdbtest
Reading symbols from gdbtest...done.
(gdb) target remote localhost:1111
Remote debugging using localhost:1111
warning: Can not parse XML target description; XML support was disabled at compile time
_start () at ../sysdeps/arm/start.S:79
79              mov fp, #0
(gdb) b main
Breakpoint 1 at 0x10920: file gdbtest.c, line 7.
(gdb) c
Continuing.

Breakpoint 1, main (argc=6, argv=0xf6fff14c) at gdbtest.c:7
7           printf("argc=%d\n",argc) ;
(gdb) l
2       #include <stdio.h>
3
4       int main(int argc, char* argv[])
5       {
6           int i ;
7           printf("argc=%d\n",argc) ;
8           for( i=0 ; i<argc ; i++ ){
9               printf("%s\n",argv[i]) ;
10          }
11          return(0) ;
(gdb)