platform: Add minimal libc support.

libfdt requires minimal libc support. Absoultely
minimum functions are added in libc.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
This commit is contained in:
Atish Patra 2019-01-17 16:38:55 -08:00 committed by Anup Patel
parent 3298251f0c
commit 1901e8a287
2 changed files with 185 additions and 0 deletions

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#
# Copyright (c) 2018 Western Digital Corporation or its affiliates.
#
# Authors:
# Atish Patra<atish.patra@wdc.com>
#
# SPDX-License-Identifier: BSD-2-Clause
#
libc_files = string.o
$(foreach file, $(libc_files), \
$(eval CFLAGS_$(file) = -I$(src)/../../common/libc))
platform-common-objs-$(PLATFORM_INCLUDE_LIBC) += $(addprefix libc/,$(libc_files))

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/*
* Copyright (c) 2018 Western Digital Corporation or its affiliates.
*
* Authors:
* Atish Patra <atish.patra@wdc.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
/*
* Simple libc functions. These are not optimized at all and might have some
* bugs as well. Use any optimized routines from newlib or glibc if required.
*/
#include <string.h>
int strcmp(const char *a, const char *b)
{
/* search first diff or end of string */
for (; *a == *b && *a != '\0'; a++, b++);
return *a - *b;
}
size_t strlen(const char *str)
{
unsigned long ret = 0;
while (*str != '\0') {
ret++;
str++;
}
return ret;
}
size_t strnlen(const char *str, size_t count)
{
unsigned long ret = 0;
while (*str != '\0' && ret < count) {
ret++;
str++;
count--;
}
return ret;
}
char * strcpy(char * dest,const char *src)
{
char *ret = dest;
while(*src != '\0') {
*dest++ = *src++;
}
return ret;
}
char * strncpy(char * dest,const char *src,size_t count)
{
char *ret = dest;
while(count-- && *src != '\0') {
*dest++ = *src++;
}
return ret;
}
char * strchr(const char * s, int c)
{
while(*s != '\0' && *s != (char)c)
s++;
if (*s == '\0')
return NULL;
else
return (char *)s;
}
char * strrchr(const char * s, int c)
{
const char *last = s + strlen(s);
while (last > s && *last != (char)c)
last--;
if (*last != (char)c)
return NULL;
else
return (char *)last;
}
void * memset(void * s,int c,size_t count)
{
char *temp = s;
while(count > 0 ){
count--;
*temp++ = c;
}
return s;
}
void * memcpy(void *dest, const void *src, size_t count)
{
char *temp1 = dest;
const char *temp2 = src;
while (count > 0) {
*temp1++ = *temp2++;
count--;
}
return dest;
}
void * memmove(void * dest,const void *src,size_t count)
{
char *temp1 = (char *)dest;
const char *temp2 = (char *)src;
if (src == dest)
return dest;
if (dest < src) {
while(count > 0) {
*temp1++ = *temp2++;
count--;
}
} else {
temp1 = dest + count - 1;
temp2 = src + count - 1;
while(count > 0) {
*temp1-- = *temp2--;
count--;
}
}
return dest;
}
int memcmp(const void * s1,const void * s2,size_t count)
{
const char *temp1 = s1;
const char *temp2 = s2;
for (; count > 0 && (*temp1 == *temp2); count--) {
temp1++;
temp2++;
}
if (count > 0)
return *(unsigned char *)temp1 - *(unsigned char *)temp2;
else
return 0;
}
void *memchr(const void *s, int c, size_t count)
{
const unsigned char *temp = s;
while (count > 0) {
if ((unsigned char)c == *temp++) {
return (void *)(temp-1);
}
count--;
}
return NULL;
}