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[newlib] minor edits and cleanups

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stnolting 2024-07-26 20:42:57 +02:00
parent 5a590ac1ab
commit a63f4c05b1
2 changed files with 17 additions and 26 deletions
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8
sw/example/demo_newlib/main.c
View file

@ -40,12 +40,6 @@ void __attribute__((destructor)) main_destructor_test(void) {
}
/**********************************************************************//**
* @name Max heap size (from linker script's "__neorv32_heap_size")
**************************************************************************/
extern char __crt0_max_heap[];
/**********************************************************************//**
* Main function: Check some of newlib's core functions.
*
@ -82,7 +76,7 @@ int main() {
// heap size definition
uint32_t max_heap = (uint32_t)&__crt0_max_heap[0];
uint32_t max_heap = (uint32_t)neorv32_heap_size_c;
if (max_heap > 0){
neorv32_uart0_printf("MAX heap size: %u bytes\n", max_heap);
}

35
sw/lib/source/syscalls.c
View file

@ -31,37 +31,25 @@
#undef errno
extern int errno;
// defined in sw/common/crt0.S
extern const volatile unsigned int __crt0_main_exit;
// linker script symbols
extern char __heap_start[];
extern char __heap_end[];
extern char __crt0_max_heap[];
void *_sbrk(int incr) {
static unsigned char *curr_heap_ptr = NULL; // current heap pointer
unsigned char *prev_heap_ptr; // previous heap pointer
const uint32_t heap_begin = (uint32_t)&__heap_start[0];
const uint32_t heap_end = (uint32_t)&__heap_end[0];
const uint32_t heap_size = (uint32_t)&__crt0_max_heap[0];
// initialize
if (curr_heap_ptr == NULL) {
curr_heap_ptr = (unsigned char *)heap_begin;
curr_heap_ptr = (unsigned char *)neorv32_heap_begin_c;
}
// do we have a heap at all?
if ((heap_begin == heap_end) || (heap_size == 0)) {
if ((neorv32_heap_begin_c == neorv32_heap_end_c) || (neorv32_heap_size_c == 0)) {
errno = ENOMEM;
return (void*)-1; // error - no more memory
}
// sufficient space left?
if ((((uint32_t)curr_heap_ptr) + ((uint32_t)incr)) >= heap_end) {
if ((((uint32_t)curr_heap_ptr) + ((uint32_t)incr)) >= neorv32_heap_end_c) {
errno = ENOMEM;
return (void*)-1; // error - no more memory
}
@ -88,7 +76,7 @@ int _fstat(int file, struct stat *st) {
int _isatty(int file) {
return 1;
return -1;
}
@ -101,9 +89,13 @@ int _lseek(int file, int ptr, int dir) {
void _exit(int status) {
// jump to crt0's shutdown code
asm volatile ("la t0, __crt0_main_exit \n"
"jr t0 \n");
while(1); // will never be reached
asm volatile (".extern __crt0_main_exit \n"
"la t0, __crt0_main_exit \n"
"jr t0 \n");
// will never be reached
__builtin_unreachable();
while(1);
}
@ -131,12 +123,14 @@ int _write(int file, char *ptr, int len) {
return len;
}
else {
errno = ENOSYS;
return 0; // nothing sent
}
}
int _read(int file, char *ptr, int len) {
int read_cnt = 0;
// read everything (STDIN, ...) from NEORV32.UART0 (if available)
@ -149,6 +143,9 @@ int _read(int file, char *ptr, int len) {
len--;
}
}
else {
errno = ENOSYS;
}
return read_cnt;
}