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nevack/util32.asm

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Utility subroutines for macOS 32bit NASM
Raw
util32.asm
; Utility routines for NASM macOS 32bit
; Nevedomsky Dmitry, 2018
; macOS 10.15 Catalina removed support for executing 32bit apps
; See util64.asm for 64bit version
;==============================================================================
; CONSTANTS
;==============================================================================
%define STDIN dword 0
%define STDOUT dword 1
%define BUFSIZE 256
%define BYTEMAX 127
%define BYTEMIN -128
%define WORDMAX 32767
%define WORDMIN -32768
%define DWORDMAX 2147483647
%define DWORDMIN -2147483648
%define SYS_OPEN dword 5
%define SYS_CLOSE dword 6
%define UMASKDEF dword 0o644
%define O_CREATE dword 0x0601
%define O_READONLY dword 0x0000
;==============================================================================
section .bss
;==============================================================================
bool resb 1
readbuf resb BUFSIZE ; buffer for read operations
;==============================================================================
section .data
;==============================================================================
msgnumerr: db "Not a number. Try again...",10,'> ',0
nl: db 10,0 ; newline msg
false: db "False",0
true: db "True",0
ten: dw 10
;==============================================================================
section .text
;==============================================================================
; void newline() - moves caret to newline
newline:
push esi
mov esi, nl
call print
pop esi
ret
; eax strlen(esi) <- Length of string at ESI, terminated by 0 or \n
strlen:
mov eax, esi
.nextchar:
cmp byte [eax], 0
je strlen.finished
inc eax
jmp strlen.nextchar
.finished:
sub eax, esi
ret
; eax checknumber(esi) - 1 if number in ESI, 0 if not
checknumber:
push esi
mov eax, esi
cmp byte [eax], '-' ; Check whether first symbol is '-'
jne checknumber.loopy
inc esi
inc eax ; if true, then skip minus
.loopy:
cmp byte [eax], 0 ; if met end
je checknumber.exityes
; cmp byte [eax], 0xA ; if met newline
; je checknumber.exityes
cmp byte [eax], '0'
jl checknumber.exitno
cmp byte [eax], '9'
jg checknumber.exitno
inc eax
jmp checknumber.loopy
.exityes:
cmp eax, esi
mov eax, 1
jne checknumber.exit
.exitno:
mov eax, 0
.exit:
pop esi
ret
; void print(esi) - prints buffer at ESI
print:
push eax
push ebx
push ecx
push edx
call strlen
push eax ; How many chars to print
push esi ; What to print
push STDOUT ; STDOUT
sub esp, 4 ; BSD call style
mov eax, 4 ; sys_write(where, what, how many)
int 80h
add esp, 16
pop edx
pop ecx
pop ebx
pop eax
ret
; void prinln(esi) - same as print, but with linefeed
println:
call print
call newline
ret
; eax read(edi) - reads from terminal at EDI, eax shows how many was read
read:
push eax
push ebx
push ecx
push edx
push eax ; How much chars to read
push edi ; Where to store
push STDIN ; STDIN
sub esp, 4 ; BSD call style
mov eax, 3 ; sys_read(what, where, how many)
int 80h ; make a syscall
mov byte [edi + eax - 1], 0 ; remove linefeed
add esp, 16 ; restore stack
pop edx
pop ecx
pop ebx
pop eax
ret
; eax atoi(esi) - converts string at ESI to number at EAX
atoi:
push esi
push ecx
push ebx
push edx
call strlen
mov ecx, eax
mov edx, 0 ; is negative
mov eax, 0
mov ebx, 0
cmp byte [esi], '-'
jne .loopy
inc esi
dec ecx
mov edx, 1
.loopy:
imul eax, 10
mov bl, byte [esi]
inc esi
sub bl, '0'
add eax, ebx
loop .loopy
cmp edx, 0
je .finish
mov edx, eax
mov eax, 0
sub eax, edx
.finish:
pop edx
pop ebx
pop ecx
pop esi
ret
; edi itoa(eax) - convert number from EAX and store it to EDI
itoa:
push edi
push edx
push ecx
push ebx
push eax
mov ecx, 0
mov ebx, 0 ; is negative
test eax, eax
jns .loopy
mov ebx, eax
mov eax, 0
sub eax, ebx
inc ecx
.loopy:
inc ecx
mov edx, 0
idiv word [ten]
add edx, '0'
push edx
cmp eax, 0
jg .loopy
cmp ebx, 0
je .loopo
push '-'
.loopo:
pop eax
mov [edi], al
inc edi
loop .loopo
mov [edi], byte 0;
pop eax
pop ebx
pop ecx
pop edx
pop edi
ret
; void printbool() - prints value of [bool]
printbool:
push esi
cmp eax, 0
je printbool.false
; true
mov esi, true
jmp printbool.printend
.false:
mov esi, false
.printend:
call print
pop esi
ret
; eax readnumber() - reads input until number typed
readint:
mov edi, readbuf
mov eax, BUFSIZE
call read
mov esi, readbuf
call checknumber
cmp eax, 0
jne .success
mov esi, msgnumerr
call print
jmp readint
.success:
mov esi, readbuf
call atoi
ret
; void exit() - exit program
exit:
push dword 0
mov eax, 1
sub esp, 4
int 0x80
; void exitcode(eax) - exit with exitcode
exitcode:
push eax
mov eax, 1
sub esp, 4
int 0x80
numerror:
mov esi, msgnumerr
call println
mov eax, 1
call exitcode
strcmp:
push esi
push edi
push ecx
push ebx
mov ecx, 0
mov ebx, 0
.loops:
cmp byte [esi + ecx], ' '
je .lesser
cmp byte [esi + ecx], 0
je .lesser
cmp byte [esi + ecx], 10
je .lesser
cmp byte [edi + ecx], ' '
je .bigger
cmp byte [edi + ecx], 0
je .bigger
cmp byte [edi + ecx], 10
je .bigger
mov bl, byte [esi + ecx]
cmp bl, byte [edi + ecx]
jg .bigger
jl .lesser
inc ecx
jmp .loops
.lesser:
mov eax, 0
jmp .end
.bigger:
mov eax, 1
.end:
pop ebx
pop ecx
pop edi
pop esi
ret
; void printword(esi) - prints word, starting at ESI, till its end
printword:
push eax
push esi
.loops:
cmp byte [esi], ' '
je .end
cmp byte [esi], 0
je .end
cmp byte [esi], 10
je .end
inc esi
jmp .loops
.end:
cmp byte [esi - 1], ','
je .punc
cmp byte [esi - 1], '.'
je .punc
cmp byte [esi - 1], ';'
je .punc
cmp byte [esi - 1], ':'
je .punc
cmp byte [esi - 1], '!'
je .punc
cmp byte [esi - 1], '?'
je .punc
cmp byte [esi - 1], '-'
je .punc
jmp .nopunc
.punc:
dec esi
.nopunc:
mov eax, esi
pop esi
sub eax, esi
cmp eax, 0
je .exit
push eax
push esi
push STDOUT
sub esp, 4
mov eax, 4
int 80h
add esp, 16
.exit:
pop eax
ret
; eax openfile(esi,eax) - opens file, with path and mode specified
openfile:
push UMASKDEF
push eax
push esi
sub esp, 4
mov eax, SYS_OPEN
int 80h
add esp, 16
ret
; void closefile(eax) - closes file by its descriptor
closefile:
push eax
sub esp, 4
mov eax, SYS_CLOSE
int 80h
add esp, 4
pop eax
ret
; void fprint(esi, eax) - write ESI contents to stream at EAX
fprint:
push ebx
mov ebx, eax
call strlen
push eax
push esi
push ebx
sub esp, 4
mov eax, 4
int 80h
add esp, 16
pop ebx
ret
; void zeroall() - make EAX,EBX,ECX,EDX zero
zeroall:
xor eax, eax
xor ebx, ebx
xor ecx, ecx
xor edx, edx
ret
Raw
util64.asm
; Utility routines for NASM macOS 64bit
; Nevedomsky Dmitry, 2021
; Usage:
; nasm -Wall -f macho64 -Ox -o test.a test.asm
; ld -macosx_version_min 10.13 -L /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib -lSystem -o run test.a
;==============================================================================
; CONSTANTS
;==============================================================================
%define STDIN dword 0
%define STDOUT dword 1
%define BUFSIZE 256
%define BYTEMAX 127
%define BYTEMIN -BYTEMAX - 1
%define WORDMAX 32767
%define WORDMIN -WORDMIN - 1
%define DWORDMAX 2147483647
%define DWORDMIN -DWORDMAX - 1
%define QWORDMAX 9223372036854775807
%define QWORDMIN -QWORDMIN - 1
%define SYS_CALL(x) 0x02000000 + x
%define SYS_EXIT SYS_CALL(1)
%define SYS_FORK SYS_CALL(2)
%define SYS_READ SYS_CALL(3)
%define SYS_WRITE SYS_CALL(4)
%define SYS_OPEN SYS_CALL(5)
%define SYS_CLOSE SYS_CALL(6)
%define SYS_OPENAT SYS_CALL(463)
%macro SYSCALL 1
mov rax, %1
syscall
%endmacro
%define UMASKDEF dword 0o644
%define O_CREATE dword 0x0601
%define O_READONLY dword 0x0000
%macro main 0-1 _main
default rel
global %1
section .text
%1:
%endmacro
%define msg(name,value) name: db value,`\0`
;==============================================================================
section .bss
;==============================================================================
bool resb 1
readbuf resb BUFSIZE ; buffer for read operations
;==============================================================================
section .data
;==============================================================================
msg(msgnumerr,`Not a number. Try again...\n> `)
msg(nl,`\n`)
msg(false,"False")
msg(true,"True")
;==============================================================================
section .text
;==============================================================================
; void newline() - moves caret to newline
newline:
mov rdi, STDOUT
lea rsi, [nl]
mov rdx, 1
SYSCALL SYS_WRITE
ret
; rax strlen(rdi) <- Length of string at RSI, terminated by 0 or \n
strlen:
mov rax, rdi
.nextchar:
cmp byte [rax], 0
je strlen.finished
inc rax
jmp strlen.nextchar
.finished:
sub rax, rdi
ret
; ; eax checknumber(esi) - 1 if number in ESI, 0 if not
; checknumber:
; push esi
; mov eax, esi
; cmp byte [eax], '-' ; Check whether first symbol is '-'
; jne checknumber.loopy
; inc esi
; inc eax ; if true, then skip minus
; .loopy:
; cmp byte [eax], 0 ; if met end
; je checknumber.exityes
; ; cmp byte [eax], 0xA ; if met newline
; ; je checknumber.exityes
; cmp byte [eax], '0'
; jl checknumber.exitno
; cmp byte [eax], '9'
; jg checknumber.exitno
; inc eax
; jmp checknumber.loopy
; .exityes:
; cmp eax, esi
; mov eax, 1
; jne checknumber.exit
; .exitno:
; mov eax, 0
; .exit:
; pop esi
; ret
; void print(rdi) - prints buffer at ESI
print:
call strlen
mov rdx, rax
mov rsi, rdi
mov rdi, STDOUT
SYSCALL SYS_WRITE
ret
; void prinln(rsi) - same as print, but with linefeed
println:
call print
call newline
ret
; rax read(rdi,rsi) - reads from terminal at RDI, eax shows how many was read
read:
mov rdx, rsi
mov rsi, rdi
mov rdi, STDIN
SYSCALL SYS_READ
mov byte [rsi + rax - 1], 0 ; remove linefeed
ret
; ; eax atoi(esi) - converts string at ESI to number at EAX
; atoi:
; push esi
; push ecx
; push ebx
; push edx
; call strlen
; mov ecx, eax
; mov edx, 0 ; is negative
; mov eax, 0
; mov ebx, 0
; cmp byte [esi], '-'
; jne .loopy
; inc esi
; dec ecx
; mov edx, 1
; .loopy:
; imul eax, 10
; mov bl, byte [esi]
; inc esi
; sub bl, '0'
; add eax, ebx
; loop .loopy
; cmp edx, 0
; je .finish
; mov edx, eax
; mov eax, 0
; sub eax, edx
; .finish:
; pop edx
; pop ebx
; pop ecx
; pop esi
; ret
; ; edi itoa(eax) - convert number from EAX and store it to EDI
; itoa:
; push edi
; push edx
; push ecx
; push ebx
; push eax
; mov ecx, 0
; mov ebx, 0 ; is negative
; test eax, eax
; jns .loopy
; mov ebx, eax
; mov eax, 0
; sub eax, ebx
; inc ecx
; .loopy:
; inc ecx
; mov edx, 0
; idiv word [ten]
; add edx, '0'
; push edx
; cmp eax, 0
; jg .loopy
; cmp ebx, 0
; je .loopo
; push '-'
; .loopo:
; pop eax
; mov [edi], al
; inc edi
; loop .loopo
; mov [edi], byte 0;
; pop eax
; pop ebx
; pop ecx
; pop edx
; pop edi
; ret
; ; void printbool() - prints value of [bool]
; printbool:
; push esi
; cmp eax, 0
; je printbool.false
; ; true
; mov esi, true
; jmp printbool.printend
; .false:
; mov esi, false
; .printend:
; call print
; pop esi
; ret
; ; eax readnumber() - reads input until number typed
; readint:
; mov edi, readbuf
; mov eax, BUFSIZE
; call read
; mov esi, readbuf
; call checknumber
; cmp eax, 0
; jne .success
; mov esi, msgnumerr
; call print
; jmp readint
; .success:
; mov esi, readbuf
; call atoi
; ret
; ; void exit() - exit program
; exit:
; push dword 0
; mov eax, 1
; sub esp, 4
; int 0x80
; void exitcode(rdi) - exit with exitcode
exitcode:
SYSCALL SYS_EXIT
; numerror:
; mov esi, msgnumerr
; call println
; mov eax, 1
; call exitcode
; strcmp:
; push esi
; push edi
; push ecx
; push ebx
; mov ecx, 0
; mov ebx, 0
; .loops:
; cmp byte [esi + ecx], ' '
; je .lesser
; cmp byte [esi + ecx], 0
; je .lesser
; cmp byte [esi + ecx], 10
; je .lesser
; cmp byte [edi + ecx], ' '
; je .bigger
; cmp byte [edi + ecx], 0
; je .bigger
; cmp byte [edi + ecx], 10
; je .bigger
; mov bl, byte [esi + ecx]
; cmp bl, byte [edi + ecx]
; jg .bigger
; jl .lesser
; inc ecx
; jmp .loops
; .lesser:
; mov eax, 0
; jmp .end
; .bigger:
; mov eax, 1
; .end:
; pop ebx
; pop ecx
; pop edi
; pop esi
; ret
; ; void printword(esi) - prints word, starting at ESI, till its end
; printword:
; push eax
; push esi
; .loops:
; cmp byte [esi], ' '
; je .end
; cmp byte [esi], 0
; je .end
; cmp byte [esi], 10
; je .end
; inc esi
; jmp .loops
; .end:
; cmp byte [esi - 1], ','
; je .punc
; cmp byte [esi - 1], '.'
; je .punc
; cmp byte [esi - 1], ';'
; je .punc
; cmp byte [esi - 1], ':'
; je .punc
; cmp byte [esi - 1], '!'
; je .punc
; cmp byte [esi - 1], '?'
; je .punc
; cmp byte [esi - 1], '-'
; je .punc
; jmp .nopunc
; .punc:
; dec esi
; .nopunc:
; mov eax, esi
; pop esi
; sub eax, esi
; cmp eax, 0
; je .exit
; push eax
; push esi
; push STDOUT
; sub esp, 4
; mov eax, 4
; int 80h
; add esp, 16
; .exit:
; pop eax
; ret
; rax openfile(rdi,rsi) - opens file, with path and mode specified
openfile:
mov rdx, UMASKDEF
SYSCALL SYS_OPEN
ret
; void closefile(rdi) - closes file by its descriptor
closefile:
SYSCALL SYS_CLOSE
ret
; void fprint(rdi, rsi) - write RSI contents to stream at RDI
fprint:
xchg rsi, rdi
call strlen
xchg rsi, rdi
mov rdx, rax
SYSCALL SYS_WRITE
ret
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