diff options
Diffstat (limited to 'apps/ex12.subx')
| -rw-r--r-- | apps/ex12.subx | 43 |
1 files changed, 0 insertions, 43 deletions
diff --git a/apps/ex12.subx b/apps/ex12.subx deleted file mode 100644 index 0c0d4315..00000000 --- a/apps/ex12.subx +++ /dev/null @@ -1,43 +0,0 @@ -# Example showing mmap syscall. -# Create a new segment using mmap, save the address, write to it. -# -# To run: -# $ ./bootstrap translate init.linux apps/ex12.subx -o apps/ex12 -# $ ./bootstrap run apps/ex12 -# You shouldn't get a segmentation fault. - -== code -# instruction effective address register displacement immediate -# . op subop mod rm32 base index scale r32 -# . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes - -Entry: - # mmap(Mmap-new-segment->len) - bb/copy-to-ebx Mmap-new-segment/imm32 - e8/call syscall_mmap/disp32 - - # write to *eax to check that we have access to the newly-allocated segment - c7 0/subop/copy 0/mod/direct 0/rm32/eax . . . . . 0x34/imm32 # copy to *eax - - # exit(eax) - 89/copy 3/mod/direct 3/rm32/ebx . . . 0/r32/eax . . # copy eax to ebx - e8/call syscall_exit/disp32 - -== data - -# various constants used here were found in the Linux sources (search for file mman-common.h) -Mmap-new-segment: # type mmap_arg_struct - # addr - 0/imm32 - # len - 0x100/imm32 - # protection flags - 3/imm32 # PROT_READ | PROT_WRITE - # sharing flags - 0x22/imm32 # MAP_PRIVATE | MAP_ANONYMOUS - # fd - -1/imm32 # since MAP_ANONYMOUS is specified - # offset - 0/imm32 # since MAP_ANONYMOUS is specified - -# . . vim:nowrap:textwidth=0 |