64 lines
1.7 KiB
Plaintext
64 lines
1.7 KiB
Plaintext
== code
|
|
|
|
open: # filename: (addr array byte), write?: boolean, out: (addr handle buffered-file)
|
|
# hard-coded parameter: file-buffer-size of created buffered-file
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
50/push-eax
|
|
51/push-ecx
|
|
52/push-edx
|
|
53/push-ebx
|
|
56/push-esi
|
|
57/push-edi
|
|
# ecx = filename
|
|
8b/-> *(ebp+8) 1/r32/ecx
|
|
# var size/edx: int = filename->length + 1 for the trailing null character
|
|
8b/-> *ecx 2/r32/edx
|
|
42/increment-edx
|
|
# var s/esi: (stream size)
|
|
29/subtract-from %esp 2/r32/edx
|
|
52/push-edx # size
|
|
68/push 0/imm32/read
|
|
68/push 0/imm32/write
|
|
89/<- %esi 4/r32/esp
|
|
# copy filename and a final null character
|
|
(clear-stream %esi)
|
|
(write %esi %ecx)
|
|
# spill edx
|
|
52/push-edx
|
|
# var fd/ecx: fd = open(filename)
|
|
8d/copy-address *(esi+0xc) 3/r32/ebx
|
|
8b/-> *(ebp+0xc) 1/r32/ecx/flags
|
|
ba/copy-to-edx 0x180/imm32/permissions
|
|
e8/call syscall_open/disp32
|
|
89/<- %ecx 0/r32/eax
|
|
# restore edx
|
|
5a/pop-to-edx
|
|
# allocate a buffered-file
|
|
(allocate Heap 0x1010 *(ebp+0x10)) # file-buffer-size + 16 for other fields
|
|
# var out-addr/edi: (addr buffered-file)
|
|
8b/-> *(ebp+0x10) 7/r32/edi
|
|
(lookup *edi *(edi+4)) # => eax
|
|
89/<- %edi 0/r32/eax
|
|
# out-addr->size = 4KB
|
|
c7 0/subop/copy *(edi+0xc) 0x1000/imm32/file-buffer-size # Stream-size + 4 for fd
|
|
# out-addr->fd = fd
|
|
89/<- *edi 1/r32/ecx
|
|
$open:end:
|
|
# . reclaim locals
|
|
01/add-to %esp 2/r32/edx
|
|
81 0/subop/add %esp 0xc/imm32
|
|
# . restore registers
|
|
5f/pop-to-edi
|
|
5e/pop-to-esi
|
|
5b/pop-to-ebx
|
|
5a/pop-to-edx
|
|
59/pop-to-ecx
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|