#include "vxBoot/loader.h"
#include "vxBoot/terminal.h"

#include <string.h>

/* loader_get_symbols() : get symbols information */
static void *loader_get_symbol(
	struct kernel * restrict const kernel,
	char const * restrict const name
) {
	char * strtab;
	uintptr_t sym;

	strtab = kernel->elf.strtab;
	for (int i = 0 ; i < kernel->elf.sym.nb ; ++i) {
		if (strcmp(&strtab[kernel->elf.sym.tab[i].st_name], name) != 0)
			continue;
		sym  = (uintptr_t)kernel->elf.sym.tab[i].st_value;
		sym += (uintptr_t)kernel->hardware.ram.physical.kernel_addr;
		sym |= (uintptr_t)0xa0000000;
		return((void*)sym);
	}
	return (NULL);
}


/* loader_got_patch() : Try to patch the GOT/PLT section */
int loader_got_patch(struct kernel * const kernel)
{
	uintptr_t *__got__;
	uintptr_t addr;
	uintptr_t got;

	/* first, try to find the _GLOBAL_OFFSET_TABLE_ symbol */
	__got__ = loader_get_symbol(kernel, "_GLOBAL_OFFSET_TABLE_");
	if (__got__ == NULL) {
		terminal_log(
			LOG_NOTICE,
			"_GLOBAL_OFFSET_TABLE_ not found...\n"
		);
		return (0);
	}

	got  = (uintptr_t)kernel->elf.got;
	got += (uintptr_t)kernel->hardware.ram.physical.kernel_addr;
	got |= (uintptr_t)0xa0000000;

	/* perform transation */
	terminal_log(LOG_DEBUG, "   _GOT_ found at %p...\n", __got__);
	terminal_log(LOG_DEBUG, "   .got  found at %p...\n", got);
	for (int i = 0 ; i < kernel->elf.got_nb ; ++i) {
		terminal_log(
			LOG_DEBUG,
			"   patch symbols %p...\n",
			((uintptr_t*)got)[i]
		);
		addr  = ((uintptr_t*)got)[i];
		addr += (uintptr_t)kernel->hardware.ram.physical.kernel_addr;
		addr |= (uintptr_t)0x80000000;
		__got__[i] = addr;
	}
	return (0);
}