diff options
Diffstat (limited to 'Core/CPU/x64/x64AsmLib/MemSet.asm')
| -rw-r--r-- | Core/CPU/x64/x64AsmLib/MemSet.asm | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/Core/CPU/x64/x64AsmLib/MemSet.asm b/Core/CPU/x64/x64AsmLib/MemSet.asm new file mode 100644 index 0000000..246b985 --- /dev/null +++ b/Core/CPU/x64/x64AsmLib/MemSet.asm @@ -0,0 +1,127 @@ +;************************************************************************* +;************************************************************************* +;** ** +;** (C)Copyright 1985-2009, American Megatrends, Inc. ** +;** ** +;** All Rights Reserved. ** +;** ** +;** 5555 Oakbrook Parkway, Suite 200, Norcross, GA 30093 ** +;** ** +;** Phone: (770)-246-8600 ** +;** ** +;************************************************************************* +;************************************************************************* + +;************************************************************************* +; $Header: /Alaska/SOURCE/Core/Modules/x64Core/x64AsmLib/MemSet.asm 1 10/01/10 5:08p Felixp $ +; +; $Revision: 1 $ +; +; $Date: 10/01/10 5:08p $ +;************************************************************************* +; Revision History +; ---------------- +; $Log: /Alaska/SOURCE/Core/Modules/x64Core/x64AsmLib/MemSet.asm $ +; +; 1 10/01/10 5:08p Felixp +; +; 1 8/24/06 12:57p Felixp +; +;************************************************************************* +;<AMI_FHDR_START> +; +; Name: +; +; Description: +; +;<AMI_FHDR_END> +;************************************************************************* +.code + +;************************************************************************* +;<AMI_PHDR_START> +; +; Name: MemSet +; +; Description: +; VOID MemSet(IN VOID *pBuffer, IN UINTN Count, IN UINT8 Value) fills Count +; bytes of memory in pBuffer with Value. +; +; Input: +; IN VOID *pBuffer +; The starting location in memory where to begin filling. +; +; IN UINTN Count +; The number of bytes to fill with Value. +; +; IN UINT8 Value +; The value to fill memory with starting at pBuffer. +; +; Output: +; VOID. +; +; Modified: +; +; Referrals: +; +; Notes: +; +;<AMI_PHDR_END> +;************************************************************************* +MemSet proc + push rdi + push rbx + mov rdi, rcx ; rdi = pBuffer + mov rcx, rdx ; rcx = Count + mov rax, r8 ; al = Value + ; fill EAX with the Value so that we can perform DWORD operatins + mov ah, al + mov bx,ax + shl rax,16 + mov ax,bx + ; if Counter is less then 4, jump to byte copy + cmp rcx, 4 + jb CopyByte + ; check if the Buffer is 4-bytes aligned + mov rdx,rdi + and rdx, 3 + ; if the Buffer is 4-bytes aligned, jump to DWORD copy + jz CopyDword + ; Buffer is not 4-bytes aligned + ; Calculate 4-(Buffer%4), which is a number of bytes we have to copy before + ; Buffer will reach 4-bytes boundary, and perform byte copy + neg rdx + add rdx, 4 + xchg rcx, rdx + sub rdx, rcx + rep stosb + mov rcx, rdx +CopyDword: + ; perform DWORD copy + mov rdx, rcx + shr rcx, 2 + rep stosd + ; copy the remainder + and rdx,3 + mov rcx, rdx +CopyByte: + rep stosb + ;;; + pop rbx + pop rdi + ret +MemSet endp + +END +;************************************************************************* +;************************************************************************* +;** ** +;** (C)Copyright 1985-2009, American Megatrends, Inc. ** +;** ** +;** All Rights Reserved. ** +;** ** +;** 5555 Oakbrook Parkway, Suite 200, Norcross, GA 30093 ** +;** ** +;** Phone: (770)-246-8600 ** +;** ** +;************************************************************************* |