https://bugzilla.tianocore.org/show_bug.cgi?id=1373 Replace BSD 2-Clause License with BSD+Patent License. This change is based on the following emails: https://lists.01.org/pipermail/edk2-devel/2019-February/036260.html https://lists.01.org/pipermail/edk2-devel/2018-October/030385.html RFCs with detailed process for the license change: V3: https://lists.01.org/pipermail/edk2-devel/2019-March/038116.html V2: https://lists.01.org/pipermail/edk2-devel/2019-March/037669.html V1: https://lists.01.org/pipermail/edk2-devel/2019-March/037500.html Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com>
		
			
				
	
	
		
			142 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			NASM
		
	
	
	
	
	
			
		
		
	
	
			142 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			NASM
		
	
	
	
	
	
;------------------------------------------------------------------------------
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;
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; CopyMem() worker for ARM
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;
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; This file started out as C code that did 64 bit moves if the buffer was
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; 32-bit aligned, else it does a byte copy. It also does a byte copy for
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; any trailing bytes. It was updated to do 32-byte copies using stm/ldm.
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;
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; Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
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; Copyright (c) 2016, Linaro Ltd. All rights reserved.<BR>
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; SPDX-License-Identifier: BSD-2-Clause-Patent
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;
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;------------------------------------------------------------------------------
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    EXPORT  InternalMemCopyMem
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    AREA    SetMem, CODE, READONLY
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    THUMB
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InternalMemCopyMem
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  stmfd  sp!, {r4-r11, lr}
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  // Save the input parameters in extra registers (r11 = destination, r14 = source, r12 = length)
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  mov  r11, r0
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  mov  r10, r0
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  mov  r12, r2
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  mov  r14, r1
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memcopy_check_overlapped
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  cmp  r11, r1
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  // If (dest < source)
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  bcc  memcopy_check_optim_default
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  // If (source + length < dest)
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  rsb  r3, r1, r11
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  cmp  r12, r3
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  bcc  memcopy_check_optim_default
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  b     memcopy_check_optim_overlap
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memcopy_check_optim_default
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  // Check if we can use an optimized path ((length >= 32) && destination word-aligned && source word-aligned) for the memcopy (optimized path if r0 == 1)
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  tst  r0, #0xF
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  movne  r0, #0
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  bne   memcopy_default
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  tst  r1, #0xF
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  movne  r3, #0
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  moveq  r3, #1
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  cmp  r2, #31
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  movls  r0, #0
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  andhi  r0, r3, #1
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  b     memcopy_default
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memcopy_check_optim_overlap
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  // r10 = dest_end, r14 = source_end
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  add  r10, r11, r12
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  add  r14, r12, r1
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  // Are we in the optimized case ((length >= 32) && dest_end word-aligned && source_end word-aligned)
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  cmp  r2, #31
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  movls  r0, #0
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  movhi  r0, #1
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  tst  r10, #0xF
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  movne  r0, #0
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  tst  r14, #0xF
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  movne  r0, #0
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  b  memcopy_overlapped
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memcopy_overlapped_non_optim
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  // We read 1 byte from the end of the source buffer
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  sub  r3, r14, #1
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  sub  r12, r12, #1
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  ldrb  r3, [r3, #0]
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  sub  r2, r10, #1
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  cmp  r12, #0
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  // We write 1 byte at the end of the dest buffer
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  sub  r10, r10, #1
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  sub  r14, r14, #1
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  strb  r3, [r2, #0]
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  bne  memcopy_overlapped_non_optim
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  b   memcopy_end
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// r10 = dest_end, r14 = source_end
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memcopy_overlapped
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  // Are we in the optimized case ?
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  cmp  r0, #0
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  beq  memcopy_overlapped_non_optim
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  // Optimized Overlapped - Read 32 bytes
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  sub  r14, r14, #32
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  sub  r12, r12, #32
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  cmp  r12, #31
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  ldmia  r14, {r2-r9}
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  // If length is less than 32 then disable optim
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  movls  r0, #0
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  cmp  r12, #0
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  // Optimized Overlapped - Write 32 bytes
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  sub  r10, r10, #32
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  stmia  r10, {r2-r9}
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  // while (length != 0)
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  bne  memcopy_overlapped
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  b   memcopy_end
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memcopy_default_non_optim
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  // Byte copy
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  ldrb  r3, [r14], #1
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  sub  r12, r12, #1
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  strb  r3, [r10], #1
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memcopy_default
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  cmp  r12, #0
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  beq  memcopy_end
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// r10 = dest, r14 = source
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memcopy_default_loop
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  cmp  r0, #0
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  beq  memcopy_default_non_optim
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  // Optimized memcopy - Read 32 Bytes
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  sub  r12, r12, #32
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  cmp  r12, #31
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  ldmia  r14!, {r2-r9}
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  // If length is less than 32 then disable optim
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  movls  r0, #0
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  cmp  r12, #0
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  // Optimized memcopy - Write 32 Bytes
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  stmia  r10!, {r2-r9}
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  // while (length != 0)
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  bne  memcopy_default_loop
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memcopy_end
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  mov  r0, r11
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  ldmfd  sp!, {r4-r11, pc}
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  END
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