memcpy.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <string.h>
#include <stdbool.h>
#include <asan.h>
 
void *memcpy(void *dest, const void *src, size_t n)
{
        unsigned long d0, d1, d2;
 
#if (ENV_ROMSTAGE && CONFIG(ASAN_IN_ROMSTAGE)) || \
                (ENV_RAMSTAGE && CONFIG(ASAN_IN_RAMSTAGE))
        check_memory_region((unsigned long)src, n, false, _RET_IP_);
        check_memory_region((unsigned long)dest, n, true, _RET_IP_);
#endif
 
        asm volatile(
#if ENV_X86_64
                "rep ; movsd\n\t"
                "mov %4,%%rcx\n\t"
#else
                "rep ; movsl\n\t"
                "movl %4,%%ecx\n\t"
#endif
                "rep ; movsb\n\t"
                : "=&c" (d0), "=&D" (d1), "=&S" (d2)
                : "0" (n >> 2), "g" (n & 3), "1" (dest), "2" (src)
                : "memory"
        );
 
        return dest;
}