// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2001
 * Raymond Lo, lo@routefree.com
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 */

/*
 * Support for harddisk partitions.
 *
 * To be compatible with LinuxPPC and Apple we use the standard Apple
 * SCSI disk partitioning scheme. For more information see:
 * http://developer.apple.com/techpubs/mac/Devices/Devices-126.html#MARKER-14-92
 */

#include <common.h>
#include <blk.h>
#include <command.h>
#include <ide.h>
#include <memalign.h>
#include <asm/unaligned.h>
#include <linux/compiler.h>
#include "part_dos.h"
#include <part.h>

#ifdef CONFIG_HAVE_BLOCK_DEVICE

#define DOS_PART_DEFAULT_SECTOR 512

/* should this be configurable? It looks like it's not very common at all
 * to use large numbers of partitions */
#define MAX_EXT_PARTS 256

static inline int is_extended(int part_type)
{
    return (part_type == DOS_PART_TYPE_EXTENDED ||
            part_type == DOS_PART_TYPE_EXTENDED_LBA ||
            part_type == DOS_PART_TYPE_EXTENDED_LINUX);
}

static int get_bootable(dos_partition_t *p)
{
        int ret = 0;

        if (p->sys_ind == 0xef)
                ret |= PART_EFI_SYSTEM_PARTITION;
        if (p->boot_ind == 0x80)
                ret |= PART_BOOTABLE;
        return ret;
}

static void print_one_part(dos_partition_t *p, lbaint_t ext_part_sector,
                           int part_num, unsigned int disksig)
{
        lbaint_t lba_start = ext_part_sector + get_unaligned_le32(p->start4);
        lbaint_t lba_size  = get_unaligned_le32(p->size4);

        printf("%3d\t%-10" LBAFlength "u\t%-10" LBAFlength
                "u\t%08x-%02x\t%02x%s%s\n",
                part_num, lba_start, lba_size, disksig, part_num, p->sys_ind,
                (is_extended(p->sys_ind) ? " Extd" : ""),
                (get_bootable(p) ? " Boot" : ""));
}

static int test_block_type(unsigned char *buffer)
{
        int slot;
        struct dos_partition *p;
        int part_count = 0;

        if((buffer[DOS_PART_MAGIC_OFFSET + 0] != 0x55) ||
            (buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) ) {
                return (-1);
        } /* no DOS Signature at all */
        p = (struct dos_partition *)&buffer[DOS_PART_TBL_OFFSET];

        /* Check that the boot indicators are valid and count the partitions. */
        for (slot = 0; slot < 4; ++slot, ++p) {
                if (p->boot_ind != 0 && p->boot_ind != 0x80)
                        break;
                if (p->sys_ind)
                        ++part_count;
        }

        /*
         * If the partition table is invalid or empty,
         * check if this is a DOS PBR
         */
        if (slot != 4 || !part_count) {
                if (!strncmp((char *)&buffer[DOS_PBR_FSTYPE_OFFSET],
                             "FAT", 3) ||
                    !strncmp((char *)&buffer[DOS_PBR32_FSTYPE_OFFSET],
                             "FAT32", 5))
                        return DOS_PBR; /* This is a DOS PBR and not an MBR */
        }
        if (slot == 4)
                return DOS_MBR; /* This is an DOS MBR */

        /* This is neither a DOS MBR nor a DOS PBR */
        return -1;
}

static int part_test_dos(struct blk_desc *dev_desc)
{
#ifndef CONFIG_SPL_BUILD
        ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, mbr,
                        DIV_ROUND_UP(dev_desc->blksz, sizeof(legacy_mbr)));

        if (blk_dread(dev_desc, 0, 1, (ulong *)mbr) != 1)
                return -1;

        if (test_block_type((unsigned char *)mbr) != DOS_MBR)
                return -1;

        if (dev_desc->sig_type == SIG_TYPE_NONE &&
            mbr->unique_mbr_signature != 0) {
                dev_desc->sig_type = SIG_TYPE_MBR;
                dev_desc->mbr_sig = mbr->unique_mbr_signature;
        }
#else
        ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);

        if (blk_dread(dev_desc, 0, 1, (ulong *)buffer) != 1)
                return -1;

        if (test_block_type(buffer) != DOS_MBR)
                return -1;
#endif

        return 0;
}

/*  Print a partition that is relative to its Extended partition table
 */
static void print_partition_extended(struct blk_desc *dev_desc,
                                     lbaint_t ext_part_sector,
                                     lbaint_t relative,
                                     int part_num, unsigned int disksig)
{
        ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
        dos_partition_t *pt;
        int i;

        /* set a maximum recursion level */
        if (part_num > MAX_EXT_PARTS)
        {
                printf("** Nested DOS partitions detected, stopping **\n");
                return;
    }

        if (blk_dread(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
                printf ("** Can't read partition table on %d:" LBAFU " **\n",
                        dev_desc->devnum, ext_part_sector);
                return;
        }
        i=test_block_type(buffer);
        if (i != DOS_MBR) {
                printf ("bad MBR sector signature 0x%02x%02x\n",
                        buffer[DOS_PART_MAGIC_OFFSET],
                        buffer[DOS_PART_MAGIC_OFFSET + 1]);
                return;
        }

        if (!ext_part_sector)
                disksig = get_unaligned_le32(&buffer[DOS_PART_DISKSIG_OFFSET]);

        /* Print all primary/logical partitions */
        pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
        for (i = 0; i < 4; i++, pt++) {
                /*
                 * fdisk does not show the extended partitions that
                 * are not in the MBR
                 */

                if ((pt->sys_ind != 0) &&
                    (ext_part_sector == 0 || !is_extended (pt->sys_ind)) ) {
                        print_one_part(pt, ext_part_sector, part_num, disksig);
                }

                /* Reverse engr the fdisk part# assignment rule! */
                if ((ext_part_sector == 0) ||
                    (pt->sys_ind != 0 && !is_extended (pt->sys_ind)) ) {
                        part_num++;
                }
        }

        /* Follows the extended partitions */
        pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
        for (i = 0; i < 4; i++, pt++) {
                if (is_extended (pt->sys_ind)) {
                        lbaint_t lba_start
                                = get_unaligned_le32 (pt->start4) + relative;

                        print_partition_extended(dev_desc, lba_start,
                                ext_part_sector == 0  ? lba_start : relative,
                                part_num, disksig);
                }
        }

        return;
}


/*  Print a partition that is relative to its Extended partition table
 */
static int part_get_info_extended(struct blk_desc *dev_desc,
                                  lbaint_t ext_part_sector, lbaint_t relative,
                                  int part_num, int which_part,
                                  struct disk_partition *info, uint disksig)
{
        ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
        dos_partition_t *pt;
        int i;
        int dos_type;

        /* set a maximum recursion level */
        if (part_num > MAX_EXT_PARTS)
        {
                printf("** Nested DOS partitions detected, stopping **\n");
                return -1;
    }

        if (blk_dread(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
                printf ("** Can't read partition table on %d:" LBAFU " **\n",
                        dev_desc->devnum, ext_part_sector);
                return -1;
        }
        if (buffer[DOS_PART_MAGIC_OFFSET] != 0x55 ||
                buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) {
                printf ("bad MBR sector signature 0x%02x%02x\n",
                        buffer[DOS_PART_MAGIC_OFFSET],
                        buffer[DOS_PART_MAGIC_OFFSET + 1]);
                return -1;
        }

#if CONFIG_IS_ENABLED(PARTITION_UUIDS)
        if (!ext_part_sector)
                disksig = get_unaligned_le32(&buffer[DOS_PART_DISKSIG_OFFSET]);
#endif

        /* Print all primary/logical partitions */
        pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
        for (i = 0; i < 4; i++, pt++) {
                /*
                 * fdisk does not show the extended partitions that
                 * are not in the MBR
                 */
                if (((pt->boot_ind & ~0x80) == 0) &&
                    (pt->sys_ind != 0) &&
                    (part_num == which_part) &&
                    (ext_part_sector == 0 || is_extended(pt->sys_ind) == 0)) {
                        info->blksz = DOS_PART_DEFAULT_SECTOR;
                        info->start = (lbaint_t)(ext_part_sector +
                                        get_unaligned_le32(pt->start4));
                        info->size  = (lbaint_t)get_unaligned_le32(pt->size4);
                        part_set_generic_name(dev_desc, part_num,
                                              (char *)info->name);
                        /* sprintf(info->type, "%d, pt->sys_ind); */
                        strcpy((char *)info->type, "U-Boot");
                        info->bootable = get_bootable(pt);
#if CONFIG_IS_ENABLED(PARTITION_UUIDS)
                        sprintf(info->uuid, "%08x-%02x", disksig, part_num);
#endif
                        info->sys_ind = pt->sys_ind;
                        return 0;
                }

                /* Reverse engr the fdisk part# assignment rule! */
                if ((ext_part_sector == 0) ||
                    (pt->sys_ind != 0 && !is_extended (pt->sys_ind)) ) {
                        part_num++;
                }
        }

        /* Follows the extended partitions */
        pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
        for (i = 0; i < 4; i++, pt++) {
                if (is_extended (pt->sys_ind)) {
                        lbaint_t lba_start
                                = get_unaligned_le32 (pt->start4) + relative;

                        return part_get_info_extended(dev_desc, lba_start,
                                 ext_part_sector == 0 ? lba_start : relative,
                                 part_num, which_part, info, disksig);
                }
        }

        /* Check for DOS PBR if no partition is found */
        dos_type = test_block_type(buffer);

        if (dos_type == DOS_PBR) {
                info->start = 0;
                info->size = dev_desc->lba;
                info->blksz = DOS_PART_DEFAULT_SECTOR;
                info->bootable = 0;
                strcpy((char *)info->type, "U-Boot");
#if CONFIG_IS_ENABLED(PARTITION_UUIDS)
                info->uuid[0] = 0;
#endif
                return 0;
        }

        return -1;
}

static void __maybe_unused part_print_dos(struct blk_desc *dev_desc)
{
        printf("Part\tStart Sector\tNum Sectors\tUUID\t\tType\n");
        print_partition_extended(dev_desc, 0, 0, 1, 0);
}

static int __maybe_unused part_get_info_dos(struct blk_desc *dev_desc, int part,
                      struct disk_partition *info)
{
        return part_get_info_extended(dev_desc, 0, 0, 1, part, info, 0);
}

int is_valid_dos_buf(void *buf)
{
        return test_block_type(buf) == DOS_MBR ? 0 : -1;
}

#if CONFIG_IS_ENABLED(CMD_MBR)
static void lba_to_chs(lbaint_t lba, unsigned char *rc, unsigned char *rh,
                       unsigned char *rs)
{
        unsigned int c, h, s;
        /* use fixed CHS geometry */
        unsigned int sectpertrack = 63;
        unsigned int heads = 255;

        c = (lba + 1) / sectpertrack / heads;
        h = (lba + 1) / sectpertrack - c * heads;
        s = (lba + 1) - (c * heads + h) * sectpertrack;

        if (c > 1023) {
                c = 1023;
                h = 254;
                s = 63;
        }

        *rc = c & 0xff;
        *rh = h;
        *rs = s + ((c & 0x300) >> 2);
}

static void mbr_fill_pt_entry(dos_partition_t *pt, lbaint_t start,
                lbaint_t relative, lbaint_t size, uchar sys_ind, bool bootable)
{
        pt->boot_ind = bootable ? 0x80 : 0x00;
        pt->sys_ind = sys_ind;
        lba_to_chs(start, &pt->cyl, &pt->head, &pt->sector);
        lba_to_chs(start + size - 1, &pt->end_cyl, &pt->end_head, &pt->end_sector);
        put_unaligned_le32(relative, &pt->start4);
        put_unaligned_le32(size, &pt->size4);
}

int write_mbr_partitions(struct blk_desc *dev,
                struct disk_partition *p, int count, unsigned int disksig)
{
        ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev->blksz);
        lbaint_t ext_part_start = 0, ext_part_size = 0, ext_part_sect = 0;
        dos_partition_t *pt;
        int i;

        memset(buffer, 0, dev->blksz);
        buffer[DOS_PART_MAGIC_OFFSET] = 0x55;
        buffer[DOS_PART_MAGIC_OFFSET + 1] = 0xaa;
        put_unaligned_le32(disksig, &buffer[DOS_PART_DISKSIG_OFFSET]);
        pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);

        /* create all primary partitions */
        for (i = 0; i < 4 && i < count; i++, pt++) {
                mbr_fill_pt_entry(pt, p[i].start, p[i].start, p[i].size,
                                  p[i].sys_ind, p[i].bootable);
                if (is_extended(p[i].sys_ind)) {
                        ext_part_start = p[i].start;
                        ext_part_size = p[i].size;
                        ext_part_sect = p[i].start;
                }
        }

        if (i < count && !ext_part_start) {
                printf("%s: extended partition is needed for more than 4 partitions\n",
                        __func__);
                return -1;
        }

        /* write MBR */
        if (blk_dwrite(dev, 0, 1, buffer) != 1) {
                printf("%s: failed writing 'MBR' (1 blks at 0x0)\n",
                       __func__);
                return -1;
        }

        /* create extended volumes */
        for (; i < count; i++) {
                lbaint_t next_ebr = 0;

                memset(buffer, 0, dev->blksz);
                buffer[DOS_PART_MAGIC_OFFSET] = 0x55;
                buffer[DOS_PART_MAGIC_OFFSET + 1] = 0xaa;
                pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);

                mbr_fill_pt_entry(pt, p[i].start, p[i].start - ext_part_sect,
                                  p[i].size, p[i].sys_ind, p[i].bootable);

                if (i + 1 < count) {
                        pt++;
                        next_ebr = p[i].start + p[i].size;
                        mbr_fill_pt_entry(pt, next_ebr,
                                          next_ebr - ext_part_start,
                                          p[i+1].start + p[i+1].size - next_ebr,
                                          DOS_PART_TYPE_EXTENDED, 0);
                }

                /* write EBR */
                if (blk_dwrite(dev, ext_part_sect, 1, buffer) != 1) {
                        printf("%s: failed writing 'EBR' (1 blks at 0x%lx)\n",
                               __func__, ext_part_sect);
                        return -1;
                }
                ext_part_sect = next_ebr;
        }

        /* Update the partition table entries*/
        part_init(dev);

        return 0;
}

int layout_mbr_partitions(struct disk_partition *p, int count,
                          lbaint_t total_sectors)
{
        struct disk_partition *ext = NULL;
        int i, j;
        lbaint_t ext_vol_start;

        /* calculate primary partitions start and size if needed */
        if (!p[0].start)
                p[0].start = DOS_PART_DEFAULT_GAP;
        for (i = 0; i < 4 && i < count; i++) {
                if (!p[i].start)
                        p[i].start = p[i - 1].start + p[i - 1].size;
                if (!p[i].size) {
                        lbaint_t end = total_sectors;
                        lbaint_t allocated = 0;

                        for (j = i + 1; j < 4 && j < count; j++) {
                                if (p[j].start) {
                                        end = p[j].start;
                                        break;
                                }
                                allocated += p[j].size;
                        }
                        p[i].size = end - allocated - p[i].start;
                }
                if (p[i].sys_ind == 0x05)
                        ext = &p[i];
        }

        if (i >= 4 && !ext) {
                printf("%s: extended partition is needed for more than 4 partitions\n",
                        __func__);
                return -1;
        }

        /* calculate extended volumes start and size if needed */
        ext_vol_start = ext->start;
        for (i = 4; i < count; i++) {
                if (!p[i].start)
                        p[i].start = ext_vol_start + DOS_PART_DEFAULT_GAP;
                if (!p[i].size) {
                        lbaint_t end = ext->start + ext->size;
                        lbaint_t allocated = 0;

                        for (j = i + 1; j < count; j++) {
                                if (p[j].start) {
                                        end = p[j].start - DOS_PART_DEFAULT_GAP;
                                        break;
                                }
                                allocated += p[j].size + DOS_PART_DEFAULT_GAP;
                        }
                        p[i].size = end - allocated - p[i].start;
                }
                ext_vol_start = p[i].start + p[i].size;
        }

        return 0;
}
#endif

int write_mbr_sector(struct blk_desc *dev_desc, void *buf)
{
        if (is_valid_dos_buf(buf))
                return -1;

        /* write MBR */
        if (blk_dwrite(dev_desc, 0, 1, buf) != 1) {
                printf("%s: failed writing '%s' (1 blks at 0x0)\n",
                       __func__, "MBR");
                return 1;
        }

        /* Update the partition table entries*/
        part_init(dev_desc);

        return 0;
}

U_BOOT_PART_TYPE(dos) = {
        .name           = "DOS",
        .part_type      = PART_TYPE_DOS,
        .max_entries    = DOS_ENTRY_NUMBERS,
        .get_info       = part_get_info_ptr(part_get_info_dos),
        .print          = part_print_ptr(part_print_dos),
        .test           = part_test_dos,
};

#endif