From 5dc0e4e0bc8011918b58baf0d8b03a3840a7b213 Mon Sep 17 00:00:00 2001 From: Solomon Peachy Date: Fri, 19 May 2023 08:56:49 -0400 Subject: disk: Support GUID Partition Tables (GPT) Notes: * Currently limited to 32-bit sector addresses due to internal Rockbox APIs. So this means a practical limit of 2TiB per drive. * Only 'General Data' GPT partition type is recognised, as that's what SD cards seem to use for exFAT/FAT32. Note that _booting_ off GPT-partitioned drive will require rebuilding the various rockbox bootloaders, and even then there may be platform limitations that preclude this. Change-Id: Ibfaae1960adcb1e81976d4b60dd596c6d16318e4 --- firmware/common/disk.c | 139 +++++++++++++++++++++++++++++++++++++++++++++---- firmware/export/disk.h | 3 ++ 2 files changed, 132 insertions(+), 10 deletions(-) diff --git a/firmware/common/disk.c b/firmware/common/disk.c index e94e161d44..554ee3cd41 100644 --- a/firmware/common/disk.c +++ b/firmware/common/disk.c @@ -44,7 +44,7 @@ #define disk_writer_lock() file_internal_lock_WRITER() #define disk_writer_unlock() file_internal_unlock_WRITER() -/* Partition table entry layout: +/* "MBR" Partition table entry layout: ----------------------- 0: 0x80 - active 1: starting head @@ -58,6 +58,16 @@ 12-15: nr of sectors in partition */ +#define BYTES2INT64(array, pos) \ + (((uint64_t)array[pos+0] << 0) | \ + ((uint64_t)array[pos+1] << 8) | \ + ((uint64_t)array[pos+2] << 16) | \ + ((uint64_t)array[pos+3] << 24) | \ + ((uint64_t)array[pos+4] << 32) | \ + ((uint64_t)array[pos+5] << 40) | \ + ((uint64_t)array[pos+6] << 48) | \ + ((uint64_t)array[pos+7] << 56) ) + #define BYTES2INT32(array, pos) \ (((uint32_t)array[pos+0] << 0) | \ ((uint32_t)array[pos+1] << 8) | \ @@ -65,11 +75,11 @@ ((uint32_t)array[pos+3] << 24)) #define BYTES2INT16(array, pos) \ - (((uint32_t)array[pos+0] << 0) | \ - ((uint32_t)array[pos+1] << 8)) + (((uint16_t)array[pos+0] << 0) | \ + ((uint16_t)array[pos+1] << 8)) /* space for 4 partitions on 2 drives */ -static struct partinfo part[NUM_DRIVES*4]; +static struct partinfo part[NUM_DRIVES*MAX_PARTITIONS_PER_DRIVE]; /* mounted to which drive (-1 if none) */ static int vol_drive[NUM_VOLUMES]; @@ -120,12 +130,13 @@ bool disk_init(IF_MD_NONVOID(int drive)) /* For each drive, start at a different position, in order not to destroy the first entry of drive 0. That one is needed to calculate config sector position. */ - struct partinfo *pinfo = &part[IF_MD_DRV(drive)*4]; + struct partinfo *pinfo = &part[IF_MD_DRV(drive)*MAX_PARTITIONS_PER_DRIVE]; + uint8_t is_gpt = 0; disk_writer_lock(); /* parse partitions */ - for (int i = 0; i < 4; i++) + for (int i = 0; i < MAX_PARTITIONS_PER_DRIVE && i < 4; i++) { unsigned char* ptr = sector + 0x1be + 16*i; pinfo[i].type = ptr[4]; @@ -140,8 +151,115 @@ bool disk_init(IF_MD_NONVOID(int drive)) { /* not handled yet */ } - } + if (pinfo[i].type == PARTITION_TYPE_GPT_GUARD) { + is_gpt = 1; + } + } + + while (is_gpt) { + /* Re-start partition parsing using GPT */ + uint64_t part_lba; + uint32_t part_entries; + uint32_t part_entry_size; + unsigned char* ptr = sector; + + storage_read_sectors(IF_MD(drive,) 1, 1, sector); + + part_lba = BYTES2INT64(ptr, 0); + if (part_lba != 0x5452415020494645ULL) { + DEBUGF("GPT: Invalid signature\n"); + break; + } + part_entry_size = BYTES2INT32(ptr, 8); + if (part_entry_size != 0x00010000) { + DEBUGF("GPT: Invalid version\n"); + break; + } + part_entry_size = BYTES2INT32(ptr, 12); + if (part_entry_size != 0x5c) { + DEBUGF("GPT: Invalid header size\n"); + break; + } + // XXX checksum header -- u32 @ offset 16 + part_entry_size = BYTES2INT32(ptr, 24); + if (part_entry_size != 1) { + DEBUGF("GPT: Invalid header LBA\n"); + break; + } + + part_lba = BYTES2INT64(ptr, 72); + part_entries = BYTES2INT32(ptr, 80); + part_entry_size = BYTES2INT32(ptr, 84); + + int part = 0; +reload: + storage_read_sectors(IF_MD(drive,) part_lba, 1, sector); + uint8_t *pptr = ptr; + while (part < MAX_PARTITIONS_PER_DRIVE && part_entries) { + if (pptr - ptr >= SECTOR_SIZE) { + part_lba++; + goto reload; + } + + /* Parse GPT entry. We only care about the "General Data" type, ie: + EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 + LE32 LE16 LE16 BE16 BE16 + */ + uint64_t tmp; + tmp = BYTES2INT32(pptr, 0); + if (tmp != 0xEBD0A0A2) + goto skip; + tmp = BYTES2INT16(pptr, 4); + if (tmp != 0xB9E5) + goto skip; + tmp = BYTES2INT16(pptr, 6); + if (tmp != 0x4433) + goto skip; + if (pptr[8] != 0x87 || pptr[9] != 0xc0) + goto skip; + if (pptr[10] != 0x68 || pptr[11] != 0xb6 || pptr[12] != 0xb7 || + pptr[13] != 0x26 || pptr[14] != 0x99 || pptr[15] != 0xc7) + goto skip; + + tmp = BYTES2INT64(pptr, 48); /* Flags */ + if (tmp) { + DEBUGF("GPT: Skip parition with flags\n"); + goto skip; /* Any flag makes us ignore this */ + } + tmp = BYTES2INT64(pptr, 32); /* FIRST LBA */ + if (tmp > UINT32_MAX) { // XXX revisit when we resize struct partinfo! + DEBUGF("GPT: partition starts after 2GiB mark\n"); + goto skip; + } + if (tmp < 34) { + DEBUGF("GPT: Invalid start LBA\n"); + goto skip; + } + pinfo[part].start = tmp; + tmp = BYTES2INT64(pptr, 40); /* LAST LBA */ + if (tmp > UINT32_MAX) { // XXX revisit when we resize struct partinfo! + DEBUGF("GPT: partition ends after 2GiB mark\n"); + goto skip; + } + if (tmp <= pinfo[part].start) { + DEBUGF("GPT: Invalid end LBA\n"); + goto skip; + } + pinfo[part].size = tmp - pinfo[part].start + 1; + pinfo[part].type = PARTITION_TYPE_FAT32_LBA; + + DEBUGF("GPart%d: start: %08lx size: %08lx\n", + part,pinfo[part].start,pinfo[part].size); + part++; + + skip: + pptr += part_entry_size; + part_entries--; + } + + is_gpt = 0; /* To break out of the loop */ + } disk_writer_unlock(); init = true; @@ -192,8 +310,7 @@ int disk_mount(int drive) disk_sector_multiplier[IF_MD_DRV(drive)] = 1; #endif - - /* try "superfloppy" mode */ + /* try "superfloppy" mode */ DEBUGF("Trying to mount sector 0.\n"); if (!fat_mount(IF_MV(volume,) IF_MD(drive,) 0)) @@ -210,12 +327,14 @@ int disk_mount(int drive) if (mounted == 0 && volume != -1) /* not a "superfloppy"? */ { for (int i = CONFIG_DEFAULT_PARTNUM; - volume != -1 && i < 4 && mounted < NUM_VOLUMES_PER_DRIVE; + volume != -1 && i < MAX_PARTITIONS_PER_DRIVE && mounted < NUM_VOLUMES_PER_DRIVE; i++) { if (pinfo[i].type == 0 || pinfo[i].type == 5) continue; /* skip free/extended partitions */ + DEBUGF("Trying to mount partition %d.\n", i); + #ifdef MAX_LOG_SECTOR_SIZE for (int j = 1; j <= (MAX_LOG_SECTOR_SIZE/SECTOR_SIZE); j <<= 1) { diff --git a/firmware/export/disk.h b/firmware/export/disk.h index c66028fe45..e465552fdc 100644 --- a/firmware/export/disk.h +++ b/firmware/export/disk.h @@ -35,6 +35,9 @@ struct partinfo #define PARTITION_TYPE_FAT32_LBA 0x0c #define PARTITION_TYPE_FAT16 0x06 #define PARTITION_TYPE_OS2_HIDDEN_C_DRIVE 0x84 +#define PARTITION_TYPE_GPT_GUARD 0xee + +#define MAX_PARTITIONS_PER_DRIVE 4 /* Needs to be at least 4 */ bool disk_init(IF_MD_NONVOID(int drive)); bool disk_partinfo(int partition, struct partinfo *info); -- cgit v1.2.3