#include "mboot.h"
#include "serial.h"
#include "shim.h"

#include <lib.h>

enum mboot_tag_type {
	MBOOT_CMDLINE = 0,
	MBOOT_MEMORYMAP = 6,
	MBOOT_SYMBOLS = 9,
	MBOOT_XSDP = 14
};

static void read_cmdline(struct boot_info *shim_info, char *data, uint8_t len) {
    if (len >= CMDLINE_MAX)
		len = CMDLINE_MAX; // truncate :(
    memcpy(shim_info->cmdline, data, len);
    shim_info->cmdline[len] = '\0';
}

static void read_memorymap(struct boot_info *shim_info, uint64_t size, uint32_t *data) {
    shim_info->map = (struct memory_map *) data;
    shim_info->map->size = size;
}

static void read_xsdp(struct boot_info *shim_info, char *data) {
    shim_info->acpi_table = (void *) data;
}

static uint32_t *read_tag(uint32_t *data, struct boot_info *shim_info) {

    uint16_t type = *((uint16_t *)data);
    uint32_t size = data[1];

    uint8_t data_len = size - 2 * sizeof(uint32_t);

    switch (type) {
        case MBOOT_CMDLINE:
            read_cmdline(shim_info, (char *)(data + 2), data_len);
            break;
        case MBOOT_MEMORYMAP:
            read_memorymap(shim_info, size, data + 2);
            break;
        case MBOOT_SYMBOLS:
            // TODO:
            break;
        case MBOOT_XSDP:
            read_xsdp(shim_info, (char *) (data + 2));
            break;
        default:
            break;
    }

    if(size % 8 != 0) {
		size += 8 - (size % 8);
	}

    return data + size / sizeof(uint32_t);
}

void mboot_load_info(
        const void *mboot_info,
        struct boot_info *shim_info
) {
    uint32_t* data = (uint32_t*) mboot_info;
    uint32_t total_size = *data++;
    data++; //reserved

    while((uint8_t*) data < (uint8_t*) mboot_info + total_size) {
        data = read_tag(data, shim_info);
    }
}