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| author | faissaloo <faissaloo@gmail.com> | 2016-07-27 12:37:01 +0100 |
|---|---|---|
| committer | faissaloo <faissaloo@gmail.com> | 2016-07-27 12:37:01 +0100 |
| commit | 39182a45f3161a8f4862b1a3086ae0f37be963c2 (patch) | |
| tree | 981ee3aa07ba0c9c6f5cb043596d6399e1967564 /sh.asm | |
| parent | 3f58585ff37ffca0f757b41a77b9e23a90393ab2 (diff) | |
| download | dbsh-39182a45f3161a8f4862b1a3086ae0f37be963c2.tar.gz | |
All buffers are now allocated by .bss and use macros for size
Diffstat (limited to 'sh.asm')
| -rw-r--r-- | sh.asm | 36 |
1 files changed, 16 insertions, 20 deletions
@@ -11,9 +11,6 @@ section .data not_func_str db "Error: program not found.", `\n` not_func_str_len equ $-not_func_str - boe_str db "Error: input overflows buffer.", `\n` - boe_str_len equ $-boe_str - no_dir_str db "cd: Unknown directory.",`\n` no_dir_str_len equ $-no_dir_str @@ -47,6 +44,16 @@ section .data sys_chdir equ 0x50 sys_waitid equ 0xf7 +section .bss + ;These must all be divisible by 16! + input_buffer_size equ 4096 + input_buffer resb input_buffer_size + + path_buffer_size equ 4096 + path_buffer resb path_buffer_size + + concat_buffer_size equ 8192 + concat_buffer resb concat_buffer_size ;Double so the path and input can never overflow concat_buffer when combined section .text global _start @@ -54,14 +61,9 @@ section .text _start: ; TODO: handle interrupt signal - push rbp - mov rbp, rsp - sub rsp, 0x110 - mov r15, rsp - sub rsp, 0x110 - mov r9, rsp - sub rsp, 0x110 - mov rbx, rsp + mov r15, input_buffer ;stdin input + mov r9, path_buffer ;PATH variable reader + mov rbx, concat_buffer ;Concatenated directory and command name ; input: none ; output: r9 (path elements), r10 (length) @@ -81,7 +83,7 @@ _start: mov rdi, rax mov rax, sys_read mov rsi, r9 - mov rdx, 0xff + mov rdx, path_buffer_size syscall test rax, rax jl _quit @@ -139,7 +141,7 @@ _read_loopr: mov rax, sys_read xor rdi, rdi ;stdin mov rsi, r15 - mov rdx, 0xff + mov rdx, input_buffer_size syscall ; check for _quit @@ -195,7 +197,7 @@ _bzero: _bzero_main: movups [r15+r8], xmm0 add r8, 16 - cmp r8, 0xff + cmp r8, input_buffer_size jl _bzero_main ret @@ -375,12 +377,6 @@ _concat_dir: add r8, 15 add r11, 15 jmp _dirty_strcpy_2 -_boe: - mov rax, sys_write - mov rdi, 0x1 - mov rsi, boe_str - mov rdx, boe_str_len - jmp _quit ; interrupt signal handler _sigint: |