From 741d5ed1b906b8763d9f346481e980e2041c9c2a Mon Sep 17 00:00:00 2001 From: Hongxu Jia Date: Wed, 30 Apr 2025 12:44:08 +0800 Subject: [PATCH] syslinux: improve isohybrid to process extra sector count for ISO 9660 image Due to commit [cdrtools-native: fix booting EFI ISO live failed] applied to improve mkisofs to fix nsectors exceeds 0xffff situation which set selection criteria type = 2 and save extra nsectors to vendor unique selection criteria In following case, add 64MB extra space to bootable image efi.img, and the partition table of EFI is truncated to 32M $ echo 'IMAGE_FSTYPES:pn-core-image-minimal = " live"' >> conf/local.conf $ echo 'MACHINE_FEATURES:append = " efi pcbios"' >> conf/local.conf $ echo '# 64MB extra space to bootable image efi.img' >> conf/local.conf $ echo 'BOOTIMG_EXTRA_SPACE = "65535"' >> conf/local.conf $ bitbake core-image-minimal $ fdisk -l tmp/deploy/images/qemux86-64/core-image-minimal-qemux86-64.rootfs.iso ... Device Boot Start End Sectors Size Id Type tmp/deploy/images/qemux86-64/core-image-minimal-qemux86-64.rootfs.iso1 * 0 376831 376832 184M 0 Empty tmp/deploy/images/qemux86-64/core-image-minimal-qemux86-64.rootfs.iso2 120 65654 65535 32M ef EFI (FAT-12/16/32) After applying this patch to process extra sector count, the partition table of EFI is 90.3M $ fdisk -l tmp/deploy/images/qemux86-64/core-image-minimal-qemux86-64.rootfs.iso ... Device Boot Start End Sectors Size Id Type tmp/deploy/images/qemux86-64/core-image-minimal-qemux86-64.rootfs.iso1 * 0 376831 376832 184M 0 Empty tmp/deploy/images/qemux86-64/core-image-minimal-qemux86-64.rootfs.iso2 120 185151 185032 90.3M ef EFI (FAT-12/16/32) [1]https://pdos.csail.mit.edu/6.828/2017/readings/boot-cdrom.pdf (From OE-Core rev: b4e112ed7e6ba5a6c6df530d696485a588831851) Signed-off-by: Hongxu Jia Signed-off-by: Mathieu Dubois-Briand Signed-off-by: Richard Purdie Signed-off-by: Steve Sakoman --- ...-count-from-section-entry-for-EFI-ca.patch | 104 ++++++++++++++++++ .../syslinux/syslinux_6.04-pre2.bb | 1 + 2 files changed, 105 insertions(+) create mode 100644 meta/recipes-devtools/syslinux/syslinux/0001-Add-extra-sector-count-from-section-entry-for-EFI-ca.patch diff --git a/meta/recipes-devtools/syslinux/syslinux/0001-Add-extra-sector-count-from-section-entry-for-EFI-ca.patch b/meta/recipes-devtools/syslinux/syslinux/0001-Add-extra-sector-count-from-section-entry-for-EFI-ca.patch new file mode 100644 index 0000000000..5422d9b2de --- /dev/null +++ b/meta/recipes-devtools/syslinux/syslinux/0001-Add-extra-sector-count-from-section-entry-for-EFI-ca.patch @@ -0,0 +1,104 @@ +From 79a26046d178ae132cb88ba75de7141bd169ff16 Mon Sep 17 00:00:00 2001 +From: Hongxu Jia +Date: Sat, 26 Apr 2025 10:45:08 +0800 +Subject: [PATCH] Add extra sector count from section entry for EFI catalogue + +According to page 11: `Figure 5 - Section Entry' in El Torito Bootable +CD-ROM Format Specification [1]. The sector count tooks 2 byte which +means max sector count is 0xffff (65535), for 512-byte sector, the +size of bootable image is no more than 32MB (65536 * 512 / 1024 / 1024) + +If the size of efi.img > 32MB, the partition table will be truncated +in ISO, which caused UEFI system or grub-efi read efi.img broken +occasionally. + +This patch extend efi_count, mac_count and count to 4 byte int, if +Yocto defines `Selection criteria type = 2', add extra sector count +to original sector count as total count; for other situation, still use +original sector count as usual + +[1]https://pdos.csail.mit.edu/6.828/2017/readings/boot-cdrom.pdf + +Upstream-Status: Inappropriate [Yocto specific] + +Signed-off-by: Hongxu Jia +--- + utils/isohybrid.c | 48 ++++++++++++++++++++++++++++++++++++++++++----- + 1 file changed, 43 insertions(+), 5 deletions(-) + +diff --git a/utils/isohybrid.c b/utils/isohybrid.c +index a9e38d4..1bbfd45 100644 +--- a/utils/isohybrid.c ++++ b/utils/isohybrid.c +@@ -76,7 +76,7 @@ uint32_t de_lba = 0; + uint16_t de_seg = 0, de_count = 0, de_mbz2 = 0; + uint8_t de_boot = 0, de_media = 0, de_sys = 0, de_mbz1 = 0; + uint32_t efi_lba = 0, mac_lba = 0; +-uint16_t efi_count = 0, mac_count = 0; ++uint32_t efi_count = 0, mac_count = 0; + uint8_t efi_boot = 0, efi_media = 0, efi_sys = 0; + + int apm_parts = 3; +@@ -552,17 +552,55 @@ read_efi_section(const uint8_t *buf) + } + + int +-read_efi_catalogue(const uint8_t *buf, uint16_t *count, uint32_t *lba) ++read_efi_catalogue(const uint8_t *buf, uint32_t *count, uint32_t *lba) + { ++ uint16_t _count = 0; ++ ++ // Jump to offset 6 byte + buf += 6; + +- memcpy(count, buf, 2); +- *count = lendian_short(*count); ++ *count = 0; ++ ++ // Offset : 6-7 byte ++ // Type : Word ++ // Description: Sector Count, the number of virtual/emulated sectors ++ // the system will store at Load Segment during the initial boot procedure ++ memcpy(&_count, buf, 2); ++ _count = lendian_short(_count); + buf += 2; + ++ // Offset : 8-0B byte ++ // Type : D Word ++ // Description: Load RBA. This is the start address of the virtual disk. CD’s use ++ // Relative/Logical block addressing. + memcpy(lba, buf, 4); + *lba = lendian_int(*lba); +- buf += 6; ++ buf += 4; ++ ++ // Offset : 0C byte ++ // Type : Byte ++ // Description: Selection criteria type. This defines a vendor unique format ++ // for bytes 0D-1F. ++ // The following formats have currently been assigned: ++ // 0 - No selection criteria ++ // 1 - Language and Version Information (IBM) ++ // 2 - Save extra sector count to vendor unique selection criteria (Yocto) ++ // 3-FF - Reserved ++ unsigned char slection_criteria_type = *buf; ++ buf += 1; ++ ++ // Offset : 0D-0E-0F-10 byte ++ // Type : D Word ++ // Description: Selection criteria type = 2, reserved by Yocto, ++ // save extra sector count to vendor unique selection criteria ++ if (slection_criteria_type == 2) { ++ memcpy(count, buf, 4); ++ *count = lendian_int(*count); ++ buf += 4; ++ } ++ ++ // total count = sector count + extra sector count ++ *count += _count; + + return 0; + } +-- +2.34.1 + diff --git a/meta/recipes-devtools/syslinux/syslinux_6.04-pre2.bb b/meta/recipes-devtools/syslinux/syslinux_6.04-pre2.bb index 7cf737170c..2522205fa1 100644 --- a/meta/recipes-devtools/syslinux/syslinux_6.04-pre2.bb +++ b/meta/recipes-devtools/syslinux/syslinux_6.04-pre2.bb @@ -23,6 +23,7 @@ SRC_URI = "https://www.zytor.com/pub/syslinux/Testing/6.04/syslinux-${PV}.tar.xz file://0013-remove-clean-script.patch \ file://0014-Fix-reproducibility-issues.patch \ file://0001-ext2_fs.h-do-not-carry-an-outdated-copy.patch \ + file://0001-Add-extra-sector-count-from-section-entry-for-EFI-ca.patch \ " SRC_URI[md5sum] = "2b31c78f087f99179feb357da312d7ec" -- 2.47.3