void* malloc(int nbytes) {
header_t* p;
header_t* prev;
u32 nunits = (nbytes+sizeof(header_t)-1)/sizeof(header_t) + 1;
if (!s_inited) _init_heap();
//semaphore_wait(&s_malloc_sem);
prev = s_start;
p = prev->next;
while(1) {
if (p->size >= nunits) {
if (p->size == nunits) {
//an exact fit!
prev->next = p->next;
}
else {
//block is bigger than we need, split it
p->size -= nunits;
p += p->size;
p->size = nunits;
}
//semaphore_signal(&s_malloc_sem);
return (void*)(p+1);
}
/*wrapped around - no block found */
if (p == s_start) {
//semaphore_signal(&s_malloc_sem);
return NULL;
}
prev = p;
p = p->next;
}
}
void kernel_start(uintptr_t magic, uintptr_t addr)
{
// Initialize default serial port
__init_serial1();
// generate checksums of read-only areas etc.
__init_sanity_checks();
// Determine where free memory starts
extern char _end;
uintptr_t free_mem_begin = reinterpret_cast<uintptr_t>(&_end);
if (magic == MULTIBOOT_BOOTLOADER_MAGIC) {
free_mem_begin = _multiboot_free_begin(addr);
}
// Preserve symbols from the ELF binary
free_mem_begin += _move_symbols(free_mem_begin);
// Initialize zero-initialized vars
_init_bss();
// Initialize heap
_init_heap(free_mem_begin);
// Initialize stack-unwinder, call global constructors etc.
_init_c_runtime();
// Initialize system calls
_init_syscalls();
// Initialize early OS, platform and devices
OS::start(magic, addr);
// Initialize common subsystems and call Service::start
OS::post_start();
// verify certain read-only sections in memory
kernel_sanity_checks();
// Starting event loop from here allows us to profile OS::start
OS::event_loop();
}
