diff options
| -rwxr-xr-x | sh | bin | 1656 -> 1648 bytes | |||
| -rw-r--r-- | sh.asm | 138 |
2 files changed, 68 insertions, 70 deletions
| Binary files differ @@ -63,7 +63,68 @@ _start: sub rsp, 0x110 mov rbx, rsp - jmp _parse_path + ; input: none + ; output: r9 (path elements), r10 (length) + ; clobbered: r8, r12 + ; other: r15 (buffer) + _parse_path: + mov rax, sys_open + mov rdi, env_str + xor rsi, rsi + syscall + test rax, rax ;check if rax is 0 + jl _quit + + call _bzero + + _parse_path2: + mov rdi, rax + mov rax, sys_read + mov rsi, r9 + mov rdx, 0xff + syscall + test rax, rax + jl _quit + mov r8, r9 + dec r8 + + ; Reads the PATH variable + mov r10, `\0\0PATH="` + _pathfinder: + inc r8 + + ;Check that we've found the PATH variable + mov rax, [r8] + shl rax, 16 + cmp rax,r10 + jne _pathfinder ;if we haven't, let's move right one and see if it's there + shr rax, 56 + test al, al ;checks for a null terminator after 'PATH=' + jz _quit + + add r8, 0x6 + mov r10, 0x1 + push 0x0 + push r8 + dec r8 + + _pathender: + inc r8 + mov al, [r8] + cmp al, `:` + je _pathender1 + cmp al, `"` + jne _pathender + mov byte [r8], 0x0 + mov r9, rsp + jmp _read_loop + + _pathender1: + inc r10 + mov byte [r8], 0x0 + lea rcx, [r8+0x1] + push rcx + jmp _pathender _read_loop: mov rax, sys_write @@ -126,69 +187,6 @@ _wait_for_proc: mov dword [cpid], -0x1 jmp _read_loop -; input: none -; output: r9 (path elements), r10 (length) -; clobbered: r8, r12 -; other: r15 (buffer) -_parse_path: - mov rax, sys_open - mov rdi, env_str - xor rsi, rsi - syscall - test rax, rax ;check if rax is 0 - jl _quit - - call _bzero - -_parse_path2: - mov rdi, rax - mov rax, sys_read - mov rsi, r9 - mov rdx, 0xff - syscall - test rax, rax - jl _quit - mov r8, r9 - dec r8 - -; Reads the PATH variable - mov r10, `\0\0PATH="` -_pathfinder: - inc r8 - - ;Check that we've found the PATH variable - mov rax, [r8] - shl rax, 16 - cmp rax,r10 - jne _pathfinder ;if we haven't, let's move right one and see if it's there - shr rax, 56 - test al, al ;checks for a null terminator after 'PATH=' - jz _quit - - add r8, 0x6 - mov r10, 0x1 - push 0x0 - push r8 - dec r8 - -_pathender: - inc r8 - mov al, [r8] - cmp al, `:` - je _pathender1 - cmp al, `"` - jne _pathender - mov byte [r8], 0x0 - mov r9, rsp - jmp _read_loop - -_pathender1: - inc r10 - mov byte [r8], 0x0 - lea rcx, [r8+0x1] - push rcx - jmp _pathender - ;Writes 0s in buffer r15 until r8 is 255 ;input: r15 (buffer) ;output: none @@ -340,7 +338,7 @@ _strlen: ; output: rbx (string) ; clobbered: r8, r11 _concat_dir: - xor r8,r8 ;new string's length (and for _dirty_strcpy_1, also the + xor r8,r8 ;new string's length (and for _dirty_strcpy_1, also the ;initial string length) ;Copies the contents of rdi to rbx in blocks of ;16, doesn't bother to clean up stuff past the null @@ -349,10 +347,10 @@ _concat_dir: _dirty_strcpy_1: movDqU xmm2, [rdi+r8] movDqU [rbx+r8],xmm2 - + pcmpistri xmm1, xmm2, 122 jz _dirty_strcpy_1_exit - + PcmpIstrI xmm0, xmm2, 122 ;if there was a null in the ;copied string exit loop jz _dirty_strcpy_1_exit @@ -367,13 +365,13 @@ _concat_dir: _dirty_strcpy_2: movdqu xmm2, [r15+r11] movdqu [rbx+r8], xmm2 - + pcmpistri xmm1, xmm2, 122 jz _parse5 - + pcmpistri xmm0, xmm2, 122 jz _parse5 - + add r8, 15 add r11, 15 jmp _dirty_strcpy_2 |