From 9c754053b07a724bdd98d039f34899d6a49115b7 Mon Sep 17 00:00:00 2001 From: bigbiff bigbiff Date: Wed, 9 Jan 2013 09:09:08 -0500 Subject: Add libtar to TWRP instead of using busybox tar Add proper mkdosfs tool Add fuse to TWRP Add experimental exfat-fuse to TWRP Convert all system() functions to use new Exec_Cmd function --- dosfstools/src/boot.c | 518 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 518 insertions(+) create mode 100644 dosfstools/src/boot.c (limited to 'dosfstools/src/boot.c') diff --git a/dosfstools/src/boot.c b/dosfstools/src/boot.c new file mode 100644 index 000000000..bbaee0471 --- /dev/null +++ b/dosfstools/src/boot.c @@ -0,0 +1,518 @@ +/* boot.c - Read and analyze ia PC/MS-DOS boot sector + + Copyright (C) 1993 Werner Almesberger + Copyright (C) 1998 Roman Hodek + + 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 3 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, see . + + On Debian systems, the complete text of the GNU General Public License + can be found in /usr/share/common-licenses/GPL-3 file. +*/ + +/* FAT32, VFAT, Atari format support, and various fixes additions May 1998 + * by Roman Hodek */ + +#include +#include +#include +#include +#include + +#include "common.h" +#include "dosfsck.h" +#include "fat.h" +#include "io.h" +#include "boot.h" + +#define ROUND_TO_MULTIPLE(n,m) ((n) && (m) ? (n)+(m)-1-((n)-1)%(m) : 0) + /* don't divide by zero */ + +/* cut-over cluster counts for FAT12 and FAT16 */ +#define FAT12_THRESHOLD 4085 +#define FAT16_THRESHOLD 65525 + +static struct { + __u8 media; + char *descr; +} mediabytes[] = { + { + 0xf0, "5.25\" or 3.5\" HD floppy"}, { + 0xf8, "hard disk"}, { + 0xf9, "3,5\" 720k floppy 2s/80tr/9sec or " + "5.25\" 1.2M floppy 2s/80tr/15sec"}, { + 0xfa, "5.25\" 320k floppy 1s/80tr/8sec"}, { + 0xfb, "3.5\" 640k floppy 2s/80tr/8sec"}, { + 0xfc, "5.25\" 180k floppy 1s/40tr/9sec"}, { + 0xfd, "5.25\" 360k floppy 2s/40tr/9sec"}, { + 0xfe, "5.25\" 160k floppy 1s/40tr/8sec"}, { +0xff, "5.25\" 320k floppy 2s/40tr/8sec"},}; + +#if defined __alpha || defined __arm || defined __arm__ || defined __ia64__ || defined __x86_64__ \ + || defined __ppc64__ || defined __bfin__ || defined __MICROBLAZE__ +/* Unaligned fields must first be copied byte-wise */ +#define GET_UNALIGNED_W(f) \ + ({ \ + unsigned short __v; \ + memcpy( &__v, &f, sizeof(__v) ); \ + CF_LE_W( *(unsigned short *)&__v ); \ + }) +#else +#define GET_UNALIGNED_W(f) CF_LE_W( *(unsigned short *)&f ) +#endif + +static char *get_media_descr(unsigned char media) +{ + int i; + + for (i = 0; i < sizeof(mediabytes) / sizeof(*mediabytes); ++i) { + if (mediabytes[i].media == media) + return (mediabytes[i].descr); + } + return ("undefined"); +} + +static void dump_boot(DOS_FS * fs, struct boot_sector *b, unsigned lss) +{ + unsigned short sectors; + + printf("Boot sector contents:\n"); + if (!atari_format) { + char id[9]; + strncpy(id, (const char *)b->system_id, 8); + id[8] = 0; + printf("System ID \"%s\"\n", id); + } else { + /* On Atari, a 24 bit serial number is stored at offset 8 of the boot + * sector */ + printf("Serial number 0x%x\n", + b->system_id[5] | (b-> + system_id[6] << 8) | (b->system_id[7] << 16)); + } + printf("Media byte 0x%02x (%s)\n", b->media, get_media_descr(b->media)); + printf("%10d bytes per logical sector\n", GET_UNALIGNED_W(b->sector_size)); + printf("%10d bytes per cluster\n", fs->cluster_size); + printf("%10d reserved sector%s\n", CF_LE_W(b->reserved), + CF_LE_W(b->reserved) == 1 ? "" : "s"); + printf("First FAT starts at byte %llu (sector %llu)\n", + (unsigned long long)fs->fat_start, + (unsigned long long)fs->fat_start / lss); + printf("%10d FATs, %d bit entries\n", b->fats, fs->fat_bits); + printf("%10d bytes per FAT (= %u sectors)\n", fs->fat_size, + fs->fat_size / lss); + if (!fs->root_cluster) { + printf("Root directory starts at byte %llu (sector %llu)\n", + (unsigned long long)fs->root_start, + (unsigned long long)fs->root_start / lss); + printf("%10d root directory entries\n", fs->root_entries); + } else { + printf("Root directory start at cluster %lu (arbitrary size)\n", + fs->root_cluster); + } + printf("Data area starts at byte %llu (sector %llu)\n", + (unsigned long long)fs->data_start, + (unsigned long long)fs->data_start / lss); + printf("%10lu data clusters (%llu bytes)\n", fs->clusters, + (unsigned long long)fs->clusters * fs->cluster_size); + printf("%u sectors/track, %u heads\n", CF_LE_W(b->secs_track), + CF_LE_W(b->heads)); + printf("%10u hidden sectors\n", atari_format ? + /* On Atari, the hidden field is only 16 bit wide and unused */ + (((unsigned char *)&b->hidden)[0] | + ((unsigned char *)&b->hidden)[1] << 8) : CF_LE_L(b->hidden)); + sectors = GET_UNALIGNED_W(b->sectors); + printf("%10u sectors total\n", sectors ? sectors : CF_LE_L(b->total_sect)); +} + +static void check_backup_boot(DOS_FS * fs, struct boot_sector *b, int lss) +{ + struct boot_sector b2; + + if (!fs->backupboot_start) { + printf("There is no backup boot sector.\n"); + if (CF_LE_W(b->reserved) < 3) { + printf("And there is no space for creating one!\n"); + return; + } + if (interactive) + printf("1) Create one\n2) Do without a backup\n"); + else + printf(" Auto-creating backup boot block.\n"); + if (!interactive || get_key("12", "?") == '1') { + int bbs; + /* The usual place for the backup boot sector is sector 6. Choose + * that or the last reserved sector. */ + if (CF_LE_W(b->reserved) >= 7 && CF_LE_W(b->info_sector) != 6) + bbs = 6; + else { + bbs = CF_LE_W(b->reserved) - 1; + if (bbs == CF_LE_W(b->info_sector)) + --bbs; /* this is never 0, as we checked reserved >= 3! */ + } + fs->backupboot_start = bbs * lss; + b->backup_boot = CT_LE_W(bbs); + fs_write(fs->backupboot_start, sizeof(*b), b); + fs_write((loff_t) offsetof(struct boot_sector, backup_boot), + sizeof(b->backup_boot), &b->backup_boot); + printf("Created backup of boot sector in sector %d\n", bbs); + return; + } else + return; + } + + fs_read(fs->backupboot_start, sizeof(b2), &b2); + if (memcmp(b, &b2, sizeof(b2)) != 0) { + /* there are any differences */ + __u8 *p, *q; + int i, pos, first = 1; + char buf[20]; + + printf("There are differences between boot sector and its backup.\n"); + printf("Differences: (offset:original/backup)\n "); + pos = 2; + for (p = (__u8 *) b, q = (__u8 *) & b2, i = 0; i < sizeof(b2); + ++p, ++q, ++i) { + if (*p != *q) { + sprintf(buf, "%s%u:%02x/%02x", first ? "" : ", ", + (unsigned)(p - (__u8 *) b), *p, *q); + if (pos + strlen(buf) > 78) + printf("\n "), pos = 2; + printf("%s", buf); + pos += strlen(buf); + first = 0; + } + } + printf("\n"); + + if (interactive) + printf("1) Copy original to backup\n" + "2) Copy backup to original\n" "3) No action\n"); + else + printf(" Not automatically fixing this.\n"); + switch (interactive ? get_key("123", "?") : '3') { + case '1': + fs_write(fs->backupboot_start, sizeof(*b), b); + break; + case '2': + fs_write(0, sizeof(b2), &b2); + break; + default: + break; + } + } +} + +static void init_fsinfo(struct info_sector *i) +{ + i->magic = CT_LE_L(0x41615252); + i->signature = CT_LE_L(0x61417272); + i->free_clusters = CT_LE_L(-1); + i->next_cluster = CT_LE_L(2); + i->boot_sign = CT_LE_W(0xaa55); +} + +static void read_fsinfo(DOS_FS * fs, struct boot_sector *b, int lss) +{ + struct info_sector i; + + if (!b->info_sector) { + printf("No FSINFO sector\n"); + if (interactive) + printf("1) Create one\n2) Do without FSINFO\n"); + else + printf(" Not automatically creating it.\n"); + if (interactive && get_key("12", "?") == '1') { + /* search for a free reserved sector (not boot sector and not + * backup boot sector) */ + __u32 s; + for (s = 1; s < CF_LE_W(b->reserved); ++s) + if (s != CF_LE_W(b->backup_boot)) + break; + if (s > 0 && s < CF_LE_W(b->reserved)) { + init_fsinfo(&i); + fs_write((loff_t) s * lss, sizeof(i), &i); + b->info_sector = CT_LE_W(s); + fs_write((loff_t) offsetof(struct boot_sector, info_sector), + sizeof(b->info_sector), &b->info_sector); + if (fs->backupboot_start) + fs_write(fs->backupboot_start + + offsetof(struct boot_sector, info_sector), + sizeof(b->info_sector), &b->info_sector); + } else { + printf("No free reserved sector found -- " + "no space for FSINFO sector!\n"); + return; + } + } else + return; + } + + fs->fsinfo_start = CF_LE_W(b->info_sector) * lss; + fs_read(fs->fsinfo_start, sizeof(i), &i); + + if (i.magic != CT_LE_L(0x41615252) || + i.signature != CT_LE_L(0x61417272) || i.boot_sign != CT_LE_W(0xaa55)) { + printf("FSINFO sector has bad magic number(s):\n"); + if (i.magic != CT_LE_L(0x41615252)) + printf(" Offset %llu: 0x%08x != expected 0x%08x\n", + (unsigned long long)offsetof(struct info_sector, magic), + CF_LE_L(i.magic), 0x41615252); + if (i.signature != CT_LE_L(0x61417272)) + printf(" Offset %llu: 0x%08x != expected 0x%08x\n", + (unsigned long long)offsetof(struct info_sector, signature), + CF_LE_L(i.signature), 0x61417272); + if (i.boot_sign != CT_LE_W(0xaa55)) + printf(" Offset %llu: 0x%04x != expected 0x%04x\n", + (unsigned long long)offsetof(struct info_sector, boot_sign), + CF_LE_W(i.boot_sign), 0xaa55); + if (interactive) + printf("1) Correct\n2) Don't correct (FSINFO invalid then)\n"); + else + printf(" Auto-correcting it.\n"); + if (!interactive || get_key("12", "?") == '1') { + init_fsinfo(&i); + fs_write(fs->fsinfo_start, sizeof(i), &i); + } else + fs->fsinfo_start = 0; + } + + if (fs->fsinfo_start) + fs->free_clusters = CF_LE_L(i.free_clusters); +} + +void read_boot(DOS_FS * fs) +{ + struct boot_sector b; + unsigned total_sectors; + unsigned short logical_sector_size, sectors; + unsigned fat_length; + loff_t data_size; + + fs_read(0, sizeof(b), &b); + logical_sector_size = GET_UNALIGNED_W(b.sector_size); + if (!logical_sector_size) + die("Logical sector size is zero."); + + /* This was moved up because it's the first thing that will fail */ + /* if the platform needs special handling of unaligned multibyte accesses */ + /* but such handling isn't being provided. See GET_UNALIGNED_W() above. */ + if (logical_sector_size & (SECTOR_SIZE - 1)) + die("Logical sector size (%d bytes) is not a multiple of the physical " + "sector size.", logical_sector_size); + + fs->cluster_size = b.cluster_size * logical_sector_size; + if (!fs->cluster_size) + die("Cluster size is zero."); + if (b.fats != 2 && b.fats != 1) + die("Currently, only 1 or 2 FATs are supported, not %d.\n", b.fats); + fs->nfats = b.fats; + sectors = GET_UNALIGNED_W(b.sectors); + total_sectors = sectors ? sectors : CF_LE_L(b.total_sect); + if (verbose) + printf("Checking we can access the last sector of the filesystem\n"); + /* Can't access last odd sector anyway, so round down */ + fs_test((loff_t) ((total_sectors & ~1) - 1) * (loff_t) logical_sector_size, + logical_sector_size); + fat_length = CF_LE_W(b.fat_length) ? + CF_LE_W(b.fat_length) : CF_LE_L(b.fat32_length); + fs->fat_start = (loff_t) CF_LE_W(b.reserved) * logical_sector_size; + fs->root_start = ((loff_t) CF_LE_W(b.reserved) + b.fats * fat_length) * + logical_sector_size; + fs->root_entries = GET_UNALIGNED_W(b.dir_entries); + fs->data_start = fs->root_start + ROUND_TO_MULTIPLE(fs->root_entries << + MSDOS_DIR_BITS, + logical_sector_size); + data_size = (loff_t) total_sectors *logical_sector_size - fs->data_start; + fs->clusters = data_size / fs->cluster_size; + fs->root_cluster = 0; /* indicates standard, pre-FAT32 root dir */ + fs->fsinfo_start = 0; /* no FSINFO structure */ + fs->free_clusters = -1; /* unknown */ + if (!b.fat_length && b.fat32_length) { + fs->fat_bits = 32; + fs->root_cluster = CF_LE_L(b.root_cluster); + if (!fs->root_cluster && fs->root_entries) + /* M$ hasn't specified this, but it looks reasonable: If + * root_cluster is 0 but there is a separate root dir + * (root_entries != 0), we handle the root dir the old way. Give a + * warning, but convertig to a root dir in a cluster chain seems + * to complex for now... */ + printf("Warning: FAT32 root dir not in cluster chain! " + "Compatibility mode...\n"); + else if (!fs->root_cluster && !fs->root_entries) + die("No root directory!"); + else if (fs->root_cluster && fs->root_entries) + printf("Warning: FAT32 root dir is in a cluster chain, but " + "a separate root dir\n" + " area is defined. Cannot fix this easily.\n"); + if (fs->clusters < FAT16_THRESHOLD) + printf("Warning: Filesystem is FAT32 according to fat_length " + "and fat32_length fields,\n" + " but has only %lu clusters, less than the required " + "minimum of %d.\n" + " This may lead to problems on some systems.\n", + fs->clusters, FAT16_THRESHOLD); + + fs->backupboot_start = CF_LE_W(b.backup_boot) * logical_sector_size; + check_backup_boot(fs, &b, logical_sector_size); + + read_fsinfo(fs, &b, logical_sector_size); + } else if (!atari_format) { + /* On real MS-DOS, a 16 bit FAT is used whenever there would be too + * much clusers otherwise. */ + fs->fat_bits = (fs->clusters >= FAT12_THRESHOLD) ? 16 : 12; + if (fs->clusters >= FAT16_THRESHOLD) + die("Too many clusters (%lu) for FAT16 filesystem.", fs->clusters); + } else { + /* On Atari, things are more difficult: GEMDOS always uses 12bit FATs + * on floppies, and always 16 bit on harddisks. */ + fs->fat_bits = 16; /* assume 16 bit FAT for now */ + /* If more clusters than fat entries in 16-bit fat, we assume + * it's a real MSDOS FS with 12-bit fat. */ + if (fs->clusters + 2 > fat_length * logical_sector_size * 8 / 16 || + /* if it's a floppy disk --> 12bit fat */ + device_no == 2 || + /* if it's a ramdisk or loopback device and has one of the usual + * floppy sizes -> 12bit FAT */ + ((device_no == 1 || device_no == 7) && + (total_sectors == 720 || total_sectors == 1440 || + total_sectors == 2880))) + fs->fat_bits = 12; + } + /* On FAT32, the high 4 bits of a FAT entry are reserved */ + fs->eff_fat_bits = (fs->fat_bits == 32) ? 28 : fs->fat_bits; + fs->fat_size = fat_length * logical_sector_size; + + fs->label = calloc(12, sizeof(__u8)); + if (fs->fat_bits == 12 || fs->fat_bits == 16) { + struct boot_sector_16 *b16 = (struct boot_sector_16 *)&b; + if (b16->extended_sig == 0x29) + memmove(fs->label, b16->label, 11); + else + fs->label = NULL; + } else if (fs->fat_bits == 32) { + if (b.extended_sig == 0x29) + memmove(fs->label, &b.label, 11); + else + fs->label = NULL; + } + + if (fs->clusters > + ((unsigned long long)fs->fat_size * 8 / fs->fat_bits) - 2) + die("File system has %d clusters but only space for %d FAT entries.", + fs->clusters, + ((unsigned long long)fs->fat_size * 8 / fs->fat_bits) - 2); + if (!fs->root_entries && !fs->root_cluster) + die("Root directory has zero size."); + if (fs->root_entries & (MSDOS_DPS - 1)) + die("Root directory (%d entries) doesn't span an integral number of " + "sectors.", fs->root_entries); + if (logical_sector_size & (SECTOR_SIZE - 1)) + die("Logical sector size (%d bytes) is not a multiple of the physical " + "sector size.", logical_sector_size); +#if 0 /* linux kernel doesn't check that either */ + /* ++roman: On Atari, these two fields are often left uninitialized */ + if (!atari_format && (!b.secs_track || !b.heads)) + die("Invalid disk format in boot sector."); +#endif + if (verbose) + dump_boot(fs, &b, logical_sector_size); +} + +static void write_boot_label(DOS_FS * fs, char *label) +{ + struct boot_sector b; + struct boot_sector_16 *b16 = (struct boot_sector_16 *)&b; + + fs_read(0, sizeof(b), &b); + if (fs->fat_bits == 12 || fs->fat_bits == 16) { + if (b16->extended_sig != 0x29) { + b16->extended_sig = 0x29; + b16->serial = 0; + memmove(b16->fs_type, fs->fat_bits == 12 ? "FAT12 " : "FAT16 ", + 8); + } + memmove(b16->label, label, 11); + } else if (fs->fat_bits == 32) { + if (b.extended_sig != 0x29) { + b.extended_sig = 0x29; + b.serial = 0; + memmove(b.fs_type, "FAT32 ", 8); + } + memmove(b.label, label, 11); + } + fs_write(0, sizeof(b), &b); + if (fs->fat_bits == 32 && fs->backupboot_start) + fs_write(fs->backupboot_start, sizeof(b), &b); +} + +static loff_t find_volume_de(DOS_FS * fs, DIR_ENT * de) +{ + unsigned long cluster; + loff_t offset; + int i; + + if (fs->root_cluster) { + for (cluster = fs->root_cluster; + cluster != 0 && cluster != -1; + cluster = next_cluster(fs, cluster)) { + offset = cluster_start(fs, cluster); + for (i = 0; i * sizeof(DIR_ENT) < fs->cluster_size; i++) { + fs_read(offset, sizeof(DIR_ENT), de); + if (de->attr & ATTR_VOLUME) + return offset; + offset += sizeof(DIR_ENT); + } + } + } else { + for (i = 0; i < fs->root_entries; i++) { + offset = fs->root_start + i * sizeof(DIR_ENT); + fs_read(offset, sizeof(DIR_ENT), de); + if (de->attr & ATTR_VOLUME) + return offset; + } + } + + return 0; +} + +static void write_volume_label(DOS_FS * fs, char *label) +{ + time_t now = time(NULL); + struct tm *mtime = localtime(&now); + loff_t offset; + DIR_ENT de; + + offset = find_volume_de(fs, &de); + if (offset == 0) + return; + + memcpy(de.name, label, 11); + de.time = CT_LE_W((unsigned short)((mtime->tm_sec >> 1) + + (mtime->tm_min << 5) + + (mtime->tm_hour << 11))); + de.date = CT_LE_W((unsigned short)(mtime->tm_mday + + ((mtime->tm_mon + 1) << 5) + + ((mtime->tm_year - 80) << 9))); + fs_write(offset, sizeof(DIR_ENT), &de); +} + +void write_label(DOS_FS * fs, char *label) +{ + int l = strlen(label); + + while (l < 11) + label[l++] = ' '; + + write_boot_label(fs, label); + write_volume_label(fs, label); +} -- cgit v1.2.3