ArmPkg/Library/BaseMemoryLibStm/Arm/SetMem.asm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; SetMem() worker for ARM
   4 ;
   5 ; This file started out as C code that did 64 bit moves if the buffer was
   6 ; 32-bit aligned, else it does a byte copy. It also does a byte copy for
   7 ; any trailing bytes. It was updated to do 32-byte at a time.
   8 ;
   9 ; Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
  10 ; This program and the accompanying materials
  11 ; are licensed and made available under the terms and conditions of the BSD License
  12 ; which accompanies this distribution.  The full text of the license may be found at
  13 ; http://opensource.org/licenses/bsd-license.php
  14 ;
  15 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  16 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  17 ;
  18
  19 /**
  20   Set Buffer to Value for Size bytes.
  21
  22   @param  Buffer   Memory to set.
  23   @param  Length   Number of bytes to set
  24   @param  Value    Value of the set operation.
  25
  26   @return Buffer
  27
  28 VOID *
  29 EFIAPI
  30 InternalMemSetMem (
  31   OUT     VOID                      *Buffer,
  32   IN      UINTN                     Length,
  33   IN      UINT8                     Value
  34   )
  35 **/
  36
  37   EXPORT InternalMemSetMem
  38
  39   AREA AsmMemStuff, CODE, READONLY
  40
  41 InternalMemSetMem
  42   stmfd  sp!, {r4-r11, lr}
  43   tst    r0, #3
  44   movne  r3, #0
  45   moveq  r3, #1
  46   cmp    r1, #31
  47   movls lr, #0
  48   andhi  lr, r3, #1
  49   cmp    lr, #0
  50   mov    r12, r0
  51   bne    L31
  52 L32
  53   mov    r3, #0
  54   b      L43
  55 L31
  56   and   r4, r2, #0xff
  57   orr   r4, r4, r4, LSL #8
  58   orr   r4, r4, r4, LSL #16
  59   mov   r5, r4
  60   mov   r6, r4
  61   mov   r7, r4
  62   mov   r8, r4
  63   mov   r9, r4
  64   mov   r10, r4
  65   mov   r11, r4
  66   b      L32
  67 L34
  68   cmp      lr, #0
  69   streqb  r2, [r12], #1
  70   subeq    r1, r1, #1
  71   beq      L43
  72   sub      r1, r1, #32
  73   cmp      r1, #31
  74   movls    lr, r3
  75   stmia    r12!, {r4-r11}
  76 L43
  77   cmp      r1, #0
  78   bne      L34
  79   ldmfd    sp!, {r4-r11, pc}
  80
  81   END