#include <stdint.h>
#include <stddef.h>
#include <debugging.h>
#include <kernel/tty.h>
#include <kernel/gdt.h>
#include <debugging.h>

static void* memcpy(void* restrict dstptr, const void* restrict srcptr, size_t size) {
	unsigned char* dst = (unsigned char*) dstptr;
	const unsigned char* src = (const unsigned char*) srcptr;
	for (size_t i = 0; i < size; i++)
		dst[i] = src[i];
	return dstptr;
}

void run_program(uint8_t* program, size_t length)
{
    uint8_t* userland_code = (uint8_t*) 0x0;
    memcpy(userland_code, program, length);

    print_hex_bytes(userland_code, 1);
    terminal_putchar('\n');

    asm ("\
    mov $0x20 | 0x3, %%ax;\
    movw %%ax, %%ds;\
    movw %%ax, %%es;\
    movw %%ax, %%fs;\
    movw %%ax, %%gs;\
    pushl $0x20 | 0x3;  /* SS  selector */ \
    pushl $0x00c00100;      /* ESP */ \
    pushf;              /* EFLAGS */    \
    popl %%eax; orl $0x200, %%eax; pushl %%eax; /* Set interrupts in USERPACE */\
    pushl $0x18 | 0x3;  /* CS selector */\
    pushl $0x0;         /* EIP */ \
    iret;":::"eax");
}