synth/arm/stdlib.cc

61 lines
1.3 KiB
C++

#include <sys/time.h>
#include <cstdint>
#include "itoa.h"
#include "lock.h"
#include "timer.h"
#include "uart.h"
#ifndef SBRK_STATS
#define SBRK_STATS 0
#endif
extern unsigned char _heap_begin, _heap_end;
namespace {
[[maybe_unused]]
void LogStats(unsigned char* heap) {
char number[] = "00000000\r\n";
UartWriteCrash("Program break now at 0x");
itoa(reinterpret_cast<int>(heap), number);
UartWriteCrash(number);
}
} // namespace
extern "C" void* _sbrk(int increment) {
static unsigned char* heap = &_heap_begin;
unsigned char* prev_heap = heap;
if (heap + increment >= &_heap_end) {
UartWriteCrash("Heap overflow!\r\n");
return reinterpret_cast<void*>(-1);
}
heap += increment;
#if SBRK_STATS
LogStats(heap);
#endif
return prev_heap;
}
extern "C" int _gettimeofday(struct timeval* tv, void* tzvp) {
uint32_t ticks = timer0->GetT1Ticks();
tv->tv_sec = ticks / 100000000;
tv->tv_usec = (ticks % 100000000) / 100;
return 0;
}
extern "C" uint8_t __atomic_exchange_1(volatile void* ptr, uint8_t val,
int memorder) {
auto* dest = reinterpret_cast<volatile uint8_t*>(ptr);
bool ret;
{
InterruptLock lock;
ret = *dest;
*dest = val;
}
return ret;
}