/*
 * Copyright (C) 2008 RuggedCom, Inc.
 * Richard Retanubun <RichardRetanubun@RuggedCom.com>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

/*
 * Problems with CONFIG_SYS_64BIT_LBA:
 *
 * struct disk_partition.start in include/part.h is sized as ulong.
 * When CONFIG_SYS_64BIT_LBA is activated, lbaint_t changes from ulong to uint64_t.
 * For now, it is cast back to ulong at assignment.
 *
 * This limits the maximum size of addressable storage to < 2 Terra Bytes
 */
#include <common.h>
#include <command.h>
#include <ide.h>
#include <malloc.h>
#include "part_efi.h"

#if defined(CONFIG_CMD_IDE) || \
    defined(CONFIG_CMD_MG_DISK) || \
    defined(CONFIG_CMD_SATA) || \
    defined(CONFIG_CMD_SCSI) || \
    defined(CONFIG_CMD_USB) || \
    defined(CONFIG_MMC) || \
    defined(CONFIG_SYSTEMACE)

/* Convert char[2] in little endian format to the host format integer
 */
static inline unsigned short le16_to_int(unsigned char *le16)
{
        return ((le16[1] << 8) + le16[0]);
}

/* Convert char[4] in little endian format to the host format integer
 */
static inline unsigned long le32_to_int(unsigned char *le32)
{
        return ((le32[3] << 24) + (le32[2] << 16) + (le32[1] << 8) + le32[0]);
}

/* Convert char[8] in little endian format to the host format integer
 */
static inline unsigned long long le64_to_int(unsigned char *le64)
{
        return (((unsigned long long)le64[7] << 56) +
                ((unsigned long long)le64[6] << 48) +
                ((unsigned long long)le64[5] << 40) +
                ((unsigned long long)le64[4] << 32) +
                ((unsigned long long)le64[3] << 24) +
                ((unsigned long long)le64[2] << 16) +
                ((unsigned long long)le64[1] << 8) +
                (unsigned long long)le64[0]);
}

/**
 * efi_crc32() - EFI version of crc32 function
 * @buf: buffer to calculate crc32 of
 * @len - length of buf
 *
 * Description: Returns EFI-style CRC32 value for @buf
 */
static inline unsigned long efi_crc32(const void *buf, unsigned long len)
{
        return crc32(0, buf, len);
}

/*
 * Private function prototypes
 */

static int pmbr_part_valid(struct partition *part);
static int is_pmbr_valid(legacy_mbr * mbr);

static int is_gpt_valid(block_dev_desc_t * dev_desc, unsigned long long lba,
                                gpt_header * pgpt_head, gpt_entry ** pgpt_pte);

static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
                                gpt_header * pgpt_head);

static int is_pte_valid(gpt_entry * pte);

/*
 * Public Functions (include/part.h)
 */

void print_part_efi(block_dev_desc_t * dev_desc)
{
        gpt_header gpt_head;
        gpt_entry **pgpt_pte = NULL;
        int i = 0;

        if (!dev_desc) {
                printf("%s: Invalid Argument(s)\n", __FUNCTION__);
                return;
        }
        /* This function validates AND fills in the GPT header and PTE */
        if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
                         &(gpt_head), pgpt_pte) != 1) {
                printf("%s: *** ERROR: Invalid GPT ***\n", __FUNCTION__);
                return;
        }

        debug("%s: gpt-entry at 0x%08X\n", __FUNCTION__, (unsigned int)*pgpt_pte);

        printf("Part  Start LBA  End LBA\n");
        for (i = 0; i < le32_to_int(gpt_head.num_partition_entries); i++) {

                if (is_pte_valid(&(*pgpt_pte)[i])) {
                        printf("%s%d  0x%llX    0x%llX\n", GPT_ENTRY_NAME,
                                (i + 1),
                                le64_to_int((*pgpt_pte)[i].starting_lba),
                                le64_to_int((*pgpt_pte)[i].ending_lba));
                } else {
                        break;  /* Stop at the first non valid PTE */
                }
        }

        /* Remember to free pte */
        if (*pgpt_pte != NULL) {
                debug("%s: Freeing pgpt_pte\n", __FUNCTION__);
                free(*pgpt_pte);
        }
        return;
}

int get_partition_info_efi(block_dev_desc_t * dev_desc, int part,
                                disk_partition_t * info)
{
        gpt_header gpt_head;
        gpt_entry **pgpt_pte = NULL;

        /* "part" argument must be at least 1 */
        if (!dev_desc || !info || part < 1) {
                printf("%s: Invalid Argument(s)\n", __FUNCTION__);
                return -1;
        }

        /* This function validates AND fills in the GPT header and PTE */
        if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
                        &(gpt_head), pgpt_pte) != 1) {
                printf("%s: *** ERROR: Invalid GPT ***\n", __FUNCTION__);
                return -1;
        }

        /* The ulong casting limits the maximum disk size to 2 TB */
        info->start = (ulong) le64_to_int((*pgpt_pte)[part - 1].starting_lba);
        /* The ending LBA is inclusive, to calculate size, add 1 to it */
        info->size = ((ulong)le64_to_int((*pgpt_pte)[part - 1].ending_lba) + 1)
                     - info->start;
        info->blksz = GPT_BLOCK_SIZE;

        sprintf((char *)info->name, "%s%d", GPT_ENTRY_NAME, part);
        sprintf((char *)info->type, "U-Boot");

        debug("%s: start 0x%lX, size 0x%lX, name %s", __FUNCTION__,
                info->start, info->size, info->name);

        /* Remember to free pte */
        if (*pgpt_pte != NULL) {
                debug("%s: Freeing pgpt_pte\n", __FUNCTION__);
                free(*pgpt_pte);
        }
        return 0;
}

int test_part_efi(block_dev_desc_t * dev_desc)
{
        legacy_mbr legacymbr;

        /* Read legacy MBR from block 0 and validate it */
        if ((dev_desc->block_read(dev_desc->dev, 0, 1, (ulong *) & legacymbr) != 1)
                || (is_pmbr_valid(&legacymbr) != 1)) {
                return -1;
        }
        return 0;
}

/*
 * Private functions
 */
/*
 * pmbr_part_valid(): Check for EFI partition signature
 *
 * Returns: 1 if EFI GPT partition type is found.
 */
static int pmbr_part_valid(struct partition *part)
{
        if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT &&
                le32_to_int(part->start_sect) == 1UL) {
                return 1;
        }

        return 0;
}

/*
 * is_pmbr_valid(): test Protective MBR for validity
 *
 * Returns: 1 if PMBR is valid, 0 otherwise.
 * Validity depends on two things:
 *  1) MSDOS signature is in the last two bytes of the MBR
 *  2) One partition of type 0xEE is found, checked by pmbr_part_valid()
 */
static int is_pmbr_valid(legacy_mbr * mbr)
{
        int i = 0;

        if (!mbr || le16_to_int(mbr->signature) != MSDOS_MBR_SIGNATURE) {
                return 0;
        }

        for (i = 0; i < 4; i++) {
                if (pmbr_part_valid(&mbr->partition_record[i])) {
                        return 1;
                }
        }
        return 0;
}

/**
 * is_gpt_valid() - tests one GPT header and PTEs for validity
 *
 * lba is the logical block address of the GPT header to test
 * gpt is a GPT header ptr, filled on return.
 * ptes is a PTEs ptr, filled on return.
 *
 * Description: returns 1 if valid,  0 on error.
 * If valid, returns pointers to PTEs.
 */
static int is_gpt_valid(block_dev_desc_t * dev_desc, unsigned long long lba,
                        gpt_header * pgpt_head, gpt_entry ** pgpt_pte)
{
        unsigned char crc32_backup[4] = { 0 };
        unsigned long calc_crc32;
        unsigned long long lastlba;

        if (!dev_desc || !pgpt_head) {
                printf("%s: Invalid Argument(s)\n", __FUNCTION__);
                return 0;
        }

        /* Read GPT Header from device */
        if (dev_desc->block_read(dev_desc->dev, lba, 1, pgpt_head) != 1) {
                printf("*** ERROR: Can't read GPT header ***\n");
                return 0;
        }

        /* Check the GPT header signature */
        if (le64_to_int(pgpt_head->signature) != GPT_HEADER_SIGNATURE) {
                printf("GUID Partition Table Header signature is wrong:"
                        "0x%llX != 0x%llX\n",
                        (unsigned long long)le64_to_int(pgpt_head->signature),
                        (unsigned long long)GPT_HEADER_SIGNATURE);
                return 0;
        }

        /* Check the GUID Partition Table CRC */
        memcpy(crc32_backup, pgpt_head->header_crc32, sizeof(crc32_backup));
        memset(pgpt_head->header_crc32, 0, sizeof(pgpt_head->header_crc32));

        calc_crc32 = efi_crc32((const unsigned char *)pgpt_head,
                le32_to_int(pgpt_head->header_size));

        memcpy(pgpt_head->header_crc32, crc32_backup, sizeof(crc32_backup));

        if (calc_crc32 != le32_to_int(crc32_backup)) {
                printf("GUID Partition Table Header CRC is wrong:"
                        "0x%08lX != 0x%08lX\n",
                        le32_to_int(crc32_backup), calc_crc32);
                return 0;
        }

        /* Check that the my_lba entry points to the LBA that contains the GPT */
        if (le64_to_int(pgpt_head->my_lba) != lba) {
                printf("GPT: my_lba incorrect: %llX != %llX\n",
                        (unsigned long long)le64_to_int(pgpt_head->my_lba),
                        (unsigned long long)lba);
                return 0;
        }

        /* Check the first_usable_lba and last_usable_lba are within the disk. */
        lastlba = (unsigned long long)dev_desc->lba;
        if (le64_to_int(pgpt_head->first_usable_lba) > lastlba) {
                printf("GPT: first_usable_lba incorrect: %llX > %llX\n",
                        le64_to_int(pgpt_head->first_usable_lba), lastlba);
                return 0;
        }
        if (le64_to_int(pgpt_head->last_usable_lba) > lastlba) {
                printf("GPT: last_usable_lba incorrect: %llX > %llX\n",
                        le64_to_int(pgpt_head->last_usable_lba), lastlba);
                return 0;
        }

        debug("GPT: first_usable_lba: %llX last_usable_lba %llX last lba %llX\n",
                le64_to_int(pgpt_head->first_usable_lba),
                le64_to_int(pgpt_head->last_usable_lba), lastlba);

        /* Read and allocate Partition Table Entries */
        *pgpt_pte = alloc_read_gpt_entries(dev_desc, pgpt_head);
        if (*pgpt_pte == NULL) {
                printf("GPT: Failed to allocate memory for PTE\n");
                return 0;
        }

        /* Check the GUID Partition Table Entry Array CRC */
        calc_crc32 = efi_crc32((const unsigned char *)*pgpt_pte,
                le32_to_int(pgpt_head->num_partition_entries) *
                le32_to_int(pgpt_head->sizeof_partition_entry));

        if (calc_crc32 != le32_to_int(pgpt_head->partition_entry_array_crc32)) {
                printf("GUID Partition Table Entry Array CRC is wrong:"
                        "0x%08lX != 0x%08lX\n",
                        le32_to_int(pgpt_head->partition_entry_array_crc32),
                        calc_crc32);

                if (*pgpt_pte != NULL) {
                        free(*pgpt_pte);
                }
                return 0;
        }

        /* We're done, all's well */
        return 1;
}

/**
 * alloc_read_gpt_entries(): reads partition entries from disk
 * @dev_desc
 * @gpt - GPT header
 *
 * Description: Returns ptes on success,  NULL on error.
 * Allocates space for PTEs based on information found in @gpt.
 * Notes: remember to free pte when you're done!
 */
static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
                                         gpt_header * pgpt_head)
{
        size_t count = 0;
        gpt_entry *pte = NULL;

        if (!dev_desc || !pgpt_head) {
                printf("%s: Invalid Argument(s)\n", __FUNCTION__);
                return NULL;
        }

        count = le32_to_int(pgpt_head->num_partition_entries) *
                le32_to_int(pgpt_head->sizeof_partition_entry);

        debug("%s: count = %lu * %lu = %u\n", __FUNCTION__,
                le32_to_int(pgpt_head->num_partition_entries),
                le32_to_int(pgpt_head->sizeof_partition_entry), count);

        /* Allocate memory for PTE, remember to FREE */
        if (count != 0) {
                pte = malloc(count);
        }

        if (count == 0 || pte == NULL) {
                printf("%s: ERROR: Can't allocate 0x%X bytes for GPT Entries\n",
                        __FUNCTION__, count);
                return NULL;
        }

        /* Read GPT Entries from device */
        if (dev_desc->block_read (dev_desc->dev,
                (unsigned long)le64_to_int(pgpt_head->partition_entry_lba),
                (lbaint_t) (count / GPT_BLOCK_SIZE), pte)
                != (count / GPT_BLOCK_SIZE)) {

                printf("*** ERROR: Can't read GPT Entries ***\n");
                free(pte);
                return NULL;
        }
        return pte;
}

/**
 * is_pte_valid(): validates a single Partition Table Entry
 * @gpt_entry - Pointer to a single Partition Table Entry
 *
 * Description: returns 1 if valid,  0 on error.
 */
static int is_pte_valid(gpt_entry * pte)
{
        efi_guid_t unused_guid;

        if (!pte) {
                printf("%s: Invalid Argument(s)\n", __FUNCTION__);
                return 0;
        }

        /* Only one validation for now:
         * The GUID Partition Type != Unused Entry (ALL-ZERO)
         */
        memset(unused_guid.b, 0, sizeof(unused_guid.b));

        if (memcmp(pte->partition_type_guid.b, unused_guid.b,
                sizeof(unused_guid.b)) == 0) {

                debug("%s: Found an unused PTE GUID at 0x%08X\n", __FUNCTION__,
                (unsigned int)pte);

                return 0;
        } else {
                return 1;
        }
}
#endif