diff --git a/lib/efi_loader/efi_freestanding.c b/lib/efi_loader/efi_freestanding.c new file mode 100644 index 0000000000..bd9da5bbc8 --- /dev/null +++ b/lib/efi_loader/efi_freestanding.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Library for freestanding binary + * + * Copyright 2019, Heinrich Schuchardt + * + * GCC requires that freestanding programs provide memcpy(), memmove(), + * memset(), and memcmp(). + */ + +#include + +/** + * memcmp() - compare memory areas + * + * @s1: pointer to first area + * @s2: pointer to second area + * @n: number of bytes to compare + * Return: 0 if both memory areas are the same, otherwise the sign of the + * result value is the same as the sign of the difference between + * the first differing pair of bytes taken as u8. + */ +int memcmp(const void *s1, const void *s2, size_t n) +{ + const u8 *pos1 = s1; + const u8 *pos2 = s2; + + for (; n; --n) { + if (*pos1 != *pos2) + return *pos1 - *pos2; + ++pos1; + ++pos2; + } + return 0; +} + +/** + * memcpy() - copy memory area + * + * @dest: destination buffer + * @src: source buffer + * @n: number of bytes to copy + * Return: pointer to destination buffer + */ +void *memmove(void *dest, const void *src, size_t n) +{ + u8 *d = dest; + const u8 *s = src; + + if (d >= s) { + for (; n; --n) + *d++ = *s++; + } else { + d += n; + s += n; + for (; n; --n) + *--d = *--s; + } + return dest; +} + +/** + * memcpy() - copy memory area + * + * @dest: destination buffer + * @src: source buffer + * @n: number of bytes to copy + * Return: pointer to destination buffer + */ +void *memcpy(void *dest, const void *src, size_t n) +{ + return memmove(dest, src, n); +} + +/** + * memset() - fill memory with a constant byte + * + * @s: destination buffer + * @c: byte value + * @n: number of bytes to set + * Return: pointer to destination buffer + */ +void *memset(void *s, int c, size_t n) +{ + u8 *d = s; + + for (; n; --n) + *d++ = c; + return s; +}