#include "console.h"
#include "multiboot2.h"

#include <def.h>
#include "console.h"
#include "multiboot2.h"
#include "panic.h"
#include "util.h"

#define MAX_REGIONS 64

typedef struct {
    u64 base_address;
    u64 length;
} memory_region;

extern uptr kernel_start;
extern uptr kernel_end;

static memory_region memory_regions[MAX_REGIONS] = {0};
static size_t memory_region_count = 0;

static void find_memory_regions(uptr multiboot_info) {
    multiboot_tag_mmap *tag = multiboot_get_mmap(multiboot_info);
    if (tag == NULL) {
        boot_panic("Multiboot did not provide mmap tag");
    }

    u32 entry_count = (tag->size - 16) / tag->entry_size;
    u8 *entry_ptr = (u8*)tag->entries;

    for (u32 i = 0; i < entry_count; ++i) {
        multiboot_mmap_entry *entry = (multiboot_mmap_entry*)entry_ptr;

        if (entry->type == MULTIBOOT_MEMORY_AVAILABLE) {
            if (memory_region_count >= MAX_REGIONS) {
                boot_panic("Too many memory regions");
            }

            memory_regions[memory_region_count++] = (memory_region){ entry->base_address, entry->length };
        }

        entry_ptr += tag->entry_size;
    }
}

// We are now in long mode with kernel pages and vga buffer identity mapped
void x86_64_main(uptr multiboot_info) {
    console_clear();
    find_memory_regions(multiboot_info);

    for (u32 i = 0; i < memory_region_count; ++i) {
        kprintf("region: base_address=0x%X, length=0x%X\n", memory_regions[i].base_address, memory_regions[i].length);
    }
}