58e97e521c
Add the `LIBC_PREVENT_STRING_KERNEL` and `LIBC_PREVENT_STRING_USER` that are meant to be selected by the chip if no libc implementation is going to be built. If selected, neither NuttX's software version of the libc nor any architecture-specific implementation will be built in the kernel or in the userspace, respectively. In this case, the linker may provide a ROM-defined version of the libc functions instead.
141 lines
3.3 KiB
ArmAsm
141 lines
3.3 KiB
ArmAsm
/****************************************************************************
|
|
* libs/libc/machine/risc-v/gnu/arch_memcpy.S
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
* License for the specific language governing permissions and limitations
|
|
* under the License.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/************************************************************************************
|
|
* Included Files
|
|
************************************************************************************/
|
|
|
|
#include "libc.h"
|
|
|
|
#ifdef LIBC_BUILD_STRING
|
|
|
|
/************************************************************************************
|
|
* Public Symbols
|
|
************************************************************************************/
|
|
|
|
.globl memcpy
|
|
.file "arch_memcpy.S"
|
|
|
|
/************************************************************************************
|
|
* Name: memcpy
|
|
************************************************************************************/
|
|
|
|
.text
|
|
|
|
memcpy:
|
|
move t6, a0 /* Preserve return value */
|
|
|
|
/* Defer to byte-oriented copy for small sizes */
|
|
sltiu a3, a2, 128
|
|
bnez a3, 4f
|
|
/* Use word-oriented copy only if low-order bits match */
|
|
andi a3, t6, 3
|
|
andi a4, a1, 3
|
|
bne a3, a4, 4f
|
|
|
|
beqz a3, 2f /* Skip if already aligned */
|
|
/*
|
|
* Round to nearest double word-aligned address
|
|
* greater than or equal to start address
|
|
*/
|
|
andi a3, a1, ~3
|
|
addi a3, a3, 4
|
|
/* Handle initial misalignment */
|
|
sub a4, a3, a1
|
|
1:
|
|
lb a5, 0(a1)
|
|
addi a1, a1, 1
|
|
sb a5, 0(t6)
|
|
addi t6, t6, 1
|
|
bltu a1, a3, 1b
|
|
sub a2, a2, a4 /* Update count */
|
|
|
|
2:
|
|
andi a4, a2, ~63
|
|
beqz a4, 4f
|
|
add a3, a1, a4
|
|
3:
|
|
lw a4, 0(a1)
|
|
lw a5, 4(a1)
|
|
lw a6, 2*4(a1)
|
|
lw a7, 3*4(a1)
|
|
lw t0, 4*4(a1)
|
|
lw t1, 5*4(a1)
|
|
lw t2, 6*4(a1)
|
|
lw t3, 7*4(a1)
|
|
lw t4, 8*4(a1)
|
|
lw t5, 9*4(a1)
|
|
sw a4, 0(t6)
|
|
sw a5, 4(t6)
|
|
sw a6, 2*4(t6)
|
|
sw a7, 3*4(t6)
|
|
sw t0, 4*4(t6)
|
|
sw t1, 5*4(t6)
|
|
sw t2, 6*4(t6)
|
|
sw t3, 7*4(t6)
|
|
sw t4, 8*4(t6)
|
|
sw t5, 9*4(t6)
|
|
lw a4, 10*4(a1)
|
|
lw a5, 11*4(a1)
|
|
lw a6, 12*4(a1)
|
|
lw a7, 13*4(a1)
|
|
lw t0, 14*4(a1)
|
|
lw t1, 15*4(a1)
|
|
addi a1, a1, 16*4
|
|
sw a4, 10*4(t6)
|
|
sw a5, 11*4(t6)
|
|
sw a6, 12*4(t6)
|
|
sw a7, 13*4(t6)
|
|
sw t0, 14*4(t6)
|
|
sw t1, 15*4(t6)
|
|
addi t6, t6, 16*4
|
|
bltu a1, a3, 3b
|
|
andi a2, a2, 63 /* Update count */
|
|
|
|
4:
|
|
/* Handle trailing misalignment */
|
|
beqz a2, 6f
|
|
add a3, a1, a2
|
|
|
|
/* Use word-oriented copy if co-aligned to word boundary */
|
|
or a5, a1, t6
|
|
or a5, a5, a3
|
|
andi a5, a5, 3
|
|
bnez a5, 5f
|
|
7:
|
|
lw a4, 0(a1)
|
|
addi a1, a1, 4
|
|
sw a4, 0(t6)
|
|
addi t6, t6, 4
|
|
bltu a1, a3, 7b
|
|
|
|
ret
|
|
|
|
5:
|
|
lb a4, 0(a1)
|
|
addi a1, a1, 1
|
|
sb a4, 0(t6)
|
|
addi t6, t6, 1
|
|
bltu a1, a3, 5b
|
|
6:
|
|
ret
|
|
|
|
#endif
|