ArmPkg/Library/BaseMemoryLibStm/Arm/SetMem.S

   1 #------------------------------------------------------------------------------
   2 #
   3 # SemMem() 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 /**
  21   Set Buffer to Value for Size bytes.
  22
  23   @param  Buffer   Memory to set.
  24   @param  Length   Number of bytes to set
  25   @param  Value    Value of the set operation.
  26
  27   @return Buffer
  28
  29 VOID *
  30 EFIAPI
  31 InternalMemSetMem (
  32   OUT     VOID                      *Buffer,
  33   IN      UINTN                     Length,
  34   IN      UINT8                     Value
  35   )
  36 **/
  37
  38 .text
  39 .syntax unified
  40 .align 2
  41 GCC_ASM_EXPORT(InternalMemSetMem)
  42
  43 ASM_PFX(InternalMemSetMem):
  44   stmfd  sp!, {r4-r11, lr}
  45   tst    r0, #3
  46   movne  r3, #0
  47   moveq  r3, #1
  48   cmp    r1, #31
  49   movls lr, #0
  50   andhi  lr, r3, #1
  51   cmp    lr, #0
  52   mov    r12, r0
  53   bne    L31
  54 L32:
  55   mov    r3, #0
  56   b      L43
  57 L31:
  58   and   r4, r2, #0xff
  59   orr   r4, r4, r4, LSL #8
  60   orr   r4, r4, r4, LSL #16
  61   mov   r5, r4
  62   mov   r6, r4
  63   mov   r7, r4
  64   mov   r8, r4
  65   mov   r9, r4
  66   mov   r10, r4
  67   mov   r11, r4
  68   b      L32
  69 L34:
  70   cmp      lr, #0
  71   strbeq  r2, [r12], #1
  72   subeq    r1, r1, #1
  73   beq      L43
  74   sub      r1, r1, #32
  75   cmp      r1, #31
  76   movls    lr, r3
  77   stmia    r12!, {r4-r11}
  78 L43:
  79   cmp      r1, #0
  80   bne      L34
  81   ldmfd    sp!, {r4-r11, pc}
  82