limine/common/lib/mem.s2.asm_ia32
2022-07-14 20:03:21 +02:00

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section .text
global memcpy
memcpy:
push esi
push edi
mov eax, dword [esp+12]
mov edi, eax
mov esi, dword [esp+16]
mov ecx, dword [esp+20]
rep movsb
pop edi
pop esi
ret
global memset
memset:
push edi
mov edx, dword [esp+8]
mov edi, edx
mov eax, dword [esp+12]
mov ecx, dword [esp+16]
rep stosb
mov eax, edx
pop edi
ret
global memmove
memmove:
push esi
push edi
mov eax, dword [esp+12]
mov edi, eax
mov esi, dword [esp+16]
mov ecx, dword [esp+20]
cmp edi, esi
ja .copy_backwards
rep movsb
jmp .done
.copy_backwards:
lea edi, [edi+ecx-1]
lea esi, [esi+ecx-1]
std
rep movsb
cld
.done:
pop edi
pop esi
ret
global memcmp
memcmp:
push esi
push edi
mov edi, dword [esp+12]
mov esi, dword [esp+16]
mov ecx, dword [esp+20]
repe cmpsb
je .equal
mov al, byte [edi-1]
sub al, byte [esi-1]
movsx eax, al
jmp .done
.equal:
xor eax, eax
.done:
pop edi
pop esi
ret
global memcpy32to64
memcpy32to64:
push ebp
mov ebp, esp
push esi
push edi
push 0x28
call .p1
.p1:
add dword [esp], .mode64 - .p1
retfd
bits 64
.mode64:
mov rdi, [rbp + 8]
mov rsi, [rbp + 16]
mov rcx, [rbp + 24]
rep movsb
push 0x18
call .p2
.p2:
add qword [rsp], .mode32 - .p2
retfq
bits 32
.mode32:
pop edi
pop esi
pop ebp
ret