kolibrios-fun/programs/develop/ktcc/trunk/libc.obj/source/crt/crt0.asm
turbocat b5b499b8c8 kolibri-libc:
Move to folder with tcc. Part 1

git-svn-id: svn://kolibrios.org@8793 a494cfbc-eb01-0410-851d-a64ba20cac60
2021-06-10 14:37:44 +00:00

222 lines
5.8 KiB
NASM

format ELF
section '.text' executable
public start
public start as '_start'
;extrn mf_init
extrn main
include '../../../../../proc32.inc'
include '../../../../../macros.inc'
include '../../../../../dll.inc'
;include '../../../../../debug.inc'
;start_:
virtual at 0
db 'MENUET01' ; 1. Magic number (8 bytes)
dd 0x01 ; 2. Version of executable file
dd start ; 3. Start address
imgsz dd 0x0 ; 4. Size of image
dd 0x100000 ; 5. Size of needed memory
dd 0x100000 ; 6. Pointer to stack
hparams dd 0x0 ; 7. Pointer to program arguments
hpath dd 0x0 ; 8. Pointer to program path
end virtual
start:
;DEBUGF 'Start programm\n'
;init heap of memory
mov eax,68
mov ebx,11
int 0x40
mov [argc], 0
mov eax, [hparams]
test eax, eax
jz .without_path
mov eax, path
cmp word ptr eax, 32fh ; '/#3' UTF8
jne .without_path
mov word ptr eax, 12fh ; '/#1' fix to CP866
.without_path:
mov esi, eax
call push_param
; retrieving parameters
mov esi, params
xor edx, edx ; dl - èä¸ò ïàðàìåòð(1) èëè ðàçäåëèòåëè(0)
; dh - ñèìâîë ñ êîòîðîãî íà÷àëñÿ ïàðàìåòð (1 êàâû÷êè, 0 îñòàëüíîå)
mov ecx, 1 ; cl = 1
; ch = 0 ïðîñòî íîëü
.parse:
lodsb
test al, al
jz .run
test dl, dl
jnz .findendparam
;{åñëè áûë ðàçäåëèòåëü
cmp al, ' '
jz .parse ;çàãðóæåí ïðîáåë, ãðóçèì ñëåäóþùèé ñèìâîë
mov dl, cl ;íà÷èíàåòñÿ ïàðàìåòð
cmp al, '"'
jz @f ;çàãðóæåíû êàâû÷êè
mov dh, ch ;ïàðàìåòð áåç êàâû÷åê
dec esi
call push_param
inc esi
jmp .parse
@@:
mov dh, cl ;ïàðàìåòð â êàâû÷åêàõ
call push_param ;åñëè íå ïðîáåë çíà÷èò íà÷èíàåòñÿ êàêîé òî ïàðàìåòð
jmp .parse ;åñëè áûë ðàçäåëèòåëü}
.findendparam:
test dh, dh
jz @f ; áåç êàâû÷åê
cmp al, '"'
jz .clear
jmp .parse
@@:
cmp al, ' '
jnz .parse
.clear:
lea ebx, [esi - 1]
mov [ebx], ch
mov dl, ch
jmp .parse
.run:
call load_imports
push argv
push [argc]
call main
.exit:
xor eax,eax
dec eax
int 0x40
dd -1
.crash:
jmp .exit
;============================
push_param:
;============================
;parameters
; esi - pointer
;description
; procedure increase argc
; and add pointer to array argv
; procedure changes ebx
mov ebx, [argc]
cmp ebx, max_parameters
jae .dont_add
mov [argv+4*ebx], esi
inc [argc]
.dont_add:
ret
;==============================
;==============================
load_imports:
;==============================
;parameters
; none
;description
; imports must be located at end of image (but before BSS sections)
; the address of end of imports (next byte after imports) is located in imgsz
; look at each import from that address up to illegal import
; legal import is such that:
; first pointer points to procedure name
; and is smaller than imgsz
; second pointer points lo library name, starting with 0x55, 0xAA
; and is smaller than imgsz
; each library should be initialized as appropriate, once
; so as library is initialized, its name will be replaced 0x00
mov ebx, [imgsz] ; byte after imports
.handle_next_import:
sub ebx, 4 ; ebx = pointer to pointer to library name
mov esi, dword[ebx] ; esi = pointer to library name
push ebx
push esi
call load_library ; eax = pointer to library exports
pop esi
pop ebx
test eax, eax
jz .done
sub ebx, 4 ; ebx = pointer to pointer to symbol name
push ebx
stdcall dll.GetProcAddress, eax, dword[ebx]
pop ebx
test eax, eax
jz .fail
mov dword[ebx], eax
jmp .handle_next_import
.done:
;DEBUGF 1, "Library: %s not loaded!\n", esi
;mcall -1
ret
.fail:
ret
;==============================
;==============================
load_library:
;==============================
;parameters
; ebx: library name address
;description
; each library should be initialized as appropriate, once
; so as library is initialized, its name will be replaced 0x00
; and 4 next bytes will be set to address of library
; first two bytes of library name must be 0x55, 0xAA (is like a magic)
cld ; move esi further, not back
cmp esi, [imgsz]
ja .fail
lodsb ; al = first byte of library name
cmp al, 0x55
jne .fail
lodsb ; al = second byte of library name
cmp al, 0xAA
jne .fail
lodsb ; al = third byte of library name (0x00 if the library is already loaded)
test al, al
jnz .load
lodsd ; if we here, then third byte is 0x00 => address of library is in next 4 bytes
; now eax contains address of library
ret
.load:
dec esi ; we checked on 0 before, let's go back
mov eax, 68
mov ebx, 19
mov ecx, esi
int 0x40 ; eax = address of exports
mov byte[esi], 0 ; library is loaded, let's place 0 in first byte of name
mov [esi + 1], eax ; now next 4 bytes of library name are replaced by address of library
; call lib_init
stdcall dll.GetProcAddress, eax, lib_init_str ; eax = address of lib_init
test eax, eax
jz .ret
stdcall dll.Init, eax
.ret:
mov eax, [esi + 1] ; put address of library into eax
ret
.fail:
mov eax, 0
ret
;==============================
lib_init_str db 'lib_init', 0
public argc as '__argc'
public params as '__argv'
public path as '__path'
section '.bss'
buf_len = 0x400
max_parameters=0x20
argc rd 1
argv rd max_parameters
path rb buf_len
params rb buf_len