/* * This provides an optimized implementation of memcpy, and a simplified * implementation of memset and memmove. These are used here because the * standard kernel runtime versions are not yet available and we don't * trust the gcc built-in implementations as they may do unexpected things * (e.g. FPU ops) in the minimal decompression stub execution environment. */ #include "../string.c" #ifdef CONFIG_X86_32 void *memcpy(void *dest, const void *src, size_t n) { int d0, d1, d2; asm volatile( "rep ; movsl\n\t" "movl %4,%%ecx\n\t" "rep ; movsb\n\t" : "=&c" (d0), "=&D" (d1), "=&S" (d2) : "0" (n >> 2), "g" (n & 3), "1" (dest), "2" (src) : "memory"); return dest; } #else void *memcpy(void *dest, const void *src, size_t n) { long d0, d1, d2; asm volatile( "rep ; movsq\n\t" "movq %4,%%rcx\n\t" "rep ; movsb\n\t" : "=&c" (d0), "=&D" (d1), "=&S" (d2) : "0" (n >> 3), "g" (n & 7), "1" (dest), "2" (src) : "memory"); return dest; } #endif void *memset(void *s, int c, size_t n) { int i; char *ss = s; for (i = 0; i < n; i++) ss[i] = c; return s; } void *memmove(void *dest, const void *src, size_t n) { unsigned char *d = dest; const unsigned char *s = src; if (d <= s || d - s >= n) return memcpy(dest, src, n); while (n-- > 0) d[n] = s[n]; return dest; }