diff options
Diffstat (limited to 'pc-bios/s390-ccw/bootmap.c')
| -rw-r--r-- | pc-bios/s390-ccw/bootmap.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c index b678d5e..415508b 100644 --- a/pc-bios/s390-ccw/bootmap.c +++ b/pc-bios/s390-ccw/bootmap.c @@ -445,6 +445,206 @@ static void ipl_scsi(void) } /*********************************************************************** + * IPL El Torito ISO9660 image or DVD + */ + +static bool is_iso_bc_entry_compatible(IsoBcSection *s) +{ + uint8_t *magic_sec = (uint8_t *)(sec + ISO_SECTOR_SIZE); + + if (s->unused || !s->sector_count) { + return false; + } + read_iso_sector(bswap32(s->load_rba), magic_sec, + "Failed to read image sector 0"); + + /* Checking bytes 8 - 32 for S390 Linux magic */ + return !_memcmp(magic_sec + 8, linux_s390_magic, 24); +} + +/* Location of the current sector of the directory */ +static uint32_t sec_loc[ISO9660_MAX_DIR_DEPTH]; +/* Offset in the current sector of the directory */ +static uint32_t sec_offset[ISO9660_MAX_DIR_DEPTH]; +/* Remained directory space in bytes */ +static uint32_t dir_rem[ISO9660_MAX_DIR_DEPTH]; + +static inline uint32_t iso_get_file_size(uint32_t load_rba) +{ + IsoVolDesc *vd = (IsoVolDesc *)sec; + IsoDirHdr *cur_record = &vd->vd.primary.rootdir; + uint8_t *temp = sec + ISO_SECTOR_SIZE; + int level = 0; + + read_iso_sector(ISO_PRIMARY_VD_SECTOR, sec, + "Failed to read ISO primary descriptor"); + sec_loc[0] = iso_733_to_u32(cur_record->ext_loc); + dir_rem[0] = 0; + sec_offset[0] = 0; + + while (level >= 0) { + IPL_assert(sec_offset[level] <= ISO_SECTOR_SIZE, + "Directory tree structure violation"); + + cur_record = (IsoDirHdr *)(temp + sec_offset[level]); + + if (sec_offset[level] == 0) { + read_iso_sector(sec_loc[level], temp, + "Failed to read ISO directory"); + if (dir_rem[level] == 0) { + /* Skip self and parent records */ + dir_rem[level] = iso_733_to_u32(cur_record->data_len) - + cur_record->dr_len; + sec_offset[level] += cur_record->dr_len; + + cur_record = (IsoDirHdr *)(temp + sec_offset[level]); + dir_rem[level] -= cur_record->dr_len; + sec_offset[level] += cur_record->dr_len; + continue; + } + } + + if (!cur_record->dr_len || sec_offset[level] == ISO_SECTOR_SIZE) { + /* Zero-padding and/or the end of current sector */ + dir_rem[level] -= ISO_SECTOR_SIZE - sec_offset[level]; + sec_offset[level] = 0; + sec_loc[level]++; + } else { + /* The directory record is valid */ + if (load_rba == iso_733_to_u32(cur_record->ext_loc)) { + return iso_733_to_u32(cur_record->data_len); + } + + dir_rem[level] -= cur_record->dr_len; + sec_offset[level] += cur_record->dr_len; + + if (cur_record->file_flags & 0x2) { + /* Subdirectory */ + if (level == ISO9660_MAX_DIR_DEPTH - 1) { + sclp_print("ISO-9660 directory depth limit exceeded\n"); + } else { + level++; + sec_loc[level] = iso_733_to_u32(cur_record->ext_loc); + sec_offset[level] = 0; + dir_rem[level] = 0; + continue; + } + } + } + + if (dir_rem[level] == 0) { + /* Nothing remaining */ + level--; + read_iso_sector(sec_loc[level], temp, + "Failed to read ISO directory"); + } + } + + return 0; +} + +static void load_iso_bc_entry(IsoBcSection *load) +{ + IsoBcSection s = *load; + /* + * According to spec, extent for each file + * is padded and ISO_SECTOR_SIZE bytes aligned + */ + uint32_t blks_to_load = bswap16(s.sector_count) >> ET_SECTOR_SHIFT; + uint32_t real_size = iso_get_file_size(bswap32(s.load_rba)); + + if (real_size) { + /* Round up blocks to load */ + blks_to_load = (real_size + ISO_SECTOR_SIZE - 1) / ISO_SECTOR_SIZE; + sclp_print("ISO boot image size verified\n"); + } else { + sclp_print("ISO boot image size could not be verified\n"); + } + + read_iso_boot_image(bswap32(s.load_rba), + (void *)((uint64_t)bswap16(s.load_segment)), + blks_to_load); + + /* Trying to get PSW at zero address */ + if (*((uint64_t *)0) & IPL_PSW_MASK) { + jump_to_IPL_code((*((uint64_t *)0)) & 0x7fffffff); + } + + /* Try default linux start address */ + jump_to_IPL_code(KERN_IMAGE_START); +} + +static uint32_t find_iso_bc(void) +{ + IsoVolDesc *vd = (IsoVolDesc *)sec; + uint32_t block_num = ISO_PRIMARY_VD_SECTOR; + + if (virtio_read_many(block_num++, sec, 1)) { + /* If primary vd cannot be read, there is no boot catalog */ + return 0; + } + + while (is_iso_vd_valid(vd) && vd->type != VOL_DESC_TERMINATOR) { + if (vd->type == VOL_DESC_TYPE_BOOT) { + IsoVdElTorito *et = &vd->vd.boot; + + if (!_memcmp(&et->el_torito[0], el_torito_magic, 32)) { + return bswap32(et->bc_offset); + } + } + read_iso_sector(block_num++, sec, + "Failed to read ISO volume descriptor"); + } + + return 0; +} + +static IsoBcSection *find_iso_bc_entry(void) +{ + IsoBcEntry *e = (IsoBcEntry *)sec; + uint32_t offset = find_iso_bc(); + int i; + + if (!offset) { + return NULL; + } + + read_iso_sector(offset, sec, "Failed to read El Torito boot catalog"); + + if (!is_iso_bc_valid(e)) { + /* The validation entry is mandatory */ + virtio_panic("No valid boot catalog found!\n"); + return NULL; + } + + /* + * Each entry has 32 bytes size, so one sector cannot contain > 64 entries. + * We consider only boot catalogs with no more than 64 entries. + */ + for (i = 1; i < ISO_BC_ENTRY_PER_SECTOR; i++) { + if (e[i].id == ISO_BC_BOOTABLE_SECTION) { + if (is_iso_bc_entry_compatible(&e[i].body.sect)) { + return &e[i].body.sect; + } + } + } + + virtio_panic("No suitable boot entry found on ISO-9660 media!\n"); + + return NULL; +} + +static void ipl_iso_el_torito(void) +{ + IsoBcSection *s = find_iso_bc_entry(); + + if (s) { + load_iso_bc_entry(s); + /* no return */ + } +} + +/*********************************************************************** * IPL starts here */ @@ -463,6 +663,12 @@ void zipl_load(void) ipl_scsi(); /* no return */ } + /* Check if we can boot as ISO media */ + if (virtio_guessed_disk_nature()) { + virtio_assume_iso9660(); + } + ipl_iso_el_torito(); + /* We have failed to follow the SCSI scheme, so */ if (virtio_guessed_disk_nature()) { sclp_print("Using guessed DASD geometry.\n"); |
