Hello Heinrich, Sorry, I'm having a hard time answering your questions.
> When writing the partition table shouldn't the offset be reflected in the protective MBR fields StartingCHS and StartingLBA? See Table 5.4 "Protective MBR Partition Record protecting the entire disk*" of the UEFI 2.10 specification. > Does Linux support this? Linux doesn't follow the protective MBR to find the GPT location if that was your question. > For testing remove the backup partition table! Testing what? The backup partition table is always restored by Linux if missing or corrupted. I tested it previously and it worked. That was the only question I could find. If your other statements intended to ask the question, please let me know. BR, Roman нд, 14 лип. 2024 р. о 09:39 Heinrich Schuchardt <xypron.g...@gmx.de> пише: > > On 7/13/24 23:16, Roman Stratiienko wrote: > > Hello Heinrich, > > > > Thank you for your comments. > > > > Just a few thoughts about this patch. > > > > 1. I was also sending this patch as a noninvasive, semi-cosmetic > > change. Relying on hardcoded values is usually not a good practice. > > 2. Shifting of primary GPT works in u-boot and Linux kernel with minor > > tweaks. See patches [1] and [2] for more context. I'm not going to > > upstream them. > > 3. Accepting this patch upstream helps me to reduce the dependency > > chain and potential conflicts during the rebase. > > Hello Roman, > > could you, please, answer my questions below. > > Best regards > > Heinrich > > > > > BR, Roman. > > > > [1]: > > https://github.com/GloDroidCommunity/amlogic-series/blob/8cc5ee7df1358092f77f43aa0c9661883473e5af/patches-aosp/glodroid/bootloader/u-boot/0005-GLODROID-Shift-GPT-position-to-support-Amlogic-platf.patch > > [2]: > > https://github.com/GloDroidCommunity/amlogic-series/blob/8cc5ee7df1358092f77f43aa0c9661883473e5af/patches-aosp/glodroid/kernel/common-android14-6.1-lts/0001-GLODROID-Allow-placing-primary-GPT-to-2MiB-offset-to.patch > > > > пн, 10 черв. 2024 р. о 15:22 Heinrich Schuchardt <xypron.g...@gmx.de> пише: > >> > >> On 19.05.24 17:35, Roman Stratiienko wrote: > >>> Use GPT_PRIMARY_PARTITION_TABLE_LBA as the only source for a primary GPT > >>> location instead of hardcoding it every time. > >>> > >>> Sometimes, we need to shift the primary GPT location. > >>> Having the location in the single place simplifies such shifting. > >> > >> In gdisk there is an expert command "j - move the main partition table". > >> This corresponds to CONFIG_EFI_PARTITION_ENTRIES_OFF. It does not move > >> the GPT primary header but only the partition entries. So sector 1 is > >> still occupied. > >> > >> If I read you correctly, CONFIG_EFI_PARTITION_ENTRIES_OFF is not doing > >> what you need. Instead of only moving the partition entries of the > >> primary partition table, you want to move the complete primary GPT table. > >> > >> Somehow the operating system must find the primary GPT table. > >> > >> When writing the partition table shouldn't the offset be reflected in > >> the protective MBR fields StartingCHS and StartingLBA? See Table 5.4 > >> "Protective MBR Partition Record protecting the entire disk*" of the > >> UEFI 2.10 specification. > >> > >> Does Linux support this? For testing remove the backup partition table! > >> > >> GPT_PRIMARY_PARTITION_TABLE_LBA should be made configurable in this case. > >> > >> Best regards > >> > >> Heinrich > >> > >>> > >>> Signed-off-by: Roman Stratiienko <r.stratiie...@gmail.com> > >>> --- > >>> disk/part_efi.c | 10 +++++----- > >>> 1 file changed, 5 insertions(+), 5 deletions(-) > >>> > >>> diff --git a/disk/part_efi.c b/disk/part_efi.c > >>> index 4ce9243ef2..b55e251ea1 100644 > >>> --- a/disk/part_efi.c > >>> +++ b/disk/part_efi.c > >>> @@ -387,7 +387,7 @@ int write_gpt_table(struct blk_desc *desc, gpt_header > >>> *gpt_h, gpt_entry *gpt_e) > >>> gpt_h->header_crc32 = cpu_to_le32(calc_crc32); > >>> > >>> /* Write the First GPT to the block right after the Legacy MBR */ > >>> - if (blk_dwrite(desc, 1, 1, gpt_h) != 1) > >>> + if (blk_dwrite(desc, (lbaint_t)le64_to_cpu(gpt_h->my_lba), 1, > >>> gpt_h) != 1) > >>> goto err; > >>> > >>> if (blk_dwrite(desc, le64_to_cpu(gpt_h->partition_entry_lba), > >>> @@ -534,7 +534,7 @@ int gpt_fill_pte(struct blk_desc *desc, > >>> > >>> static uint32_t partition_entries_offset(struct blk_desc *desc) > >>> { > >>> - uint32_t offset_blks = 2; > >>> + uint32_t offset_blks = GPT_PRIMARY_PARTITION_TABLE_LBA + 1; > >>> uint32_t __maybe_unused offset_bytes; > >>> int __maybe_unused config_offset; > >>> > >>> @@ -572,8 +572,8 @@ static uint32_t partition_entries_offset(struct > >>> blk_desc *desc) > >>> * The earliest LBA this can be at is LBA#2 (i.e. right behind > >>> * the (protective) MBR and the GPT header. > >>> */ > >>> - if (offset_blks < 2) > >>> - offset_blks = 2; > >>> + if (offset_blks < (GPT_PRIMARY_PARTITION_TABLE_LBA + 1)) > >>> + offset_blks = GPT_PRIMARY_PARTITION_TABLE_LBA + 1; > >>> > >>> return offset_blks; > >>> } > >>> @@ -584,7 +584,7 @@ int gpt_fill_header(struct blk_desc *desc, gpt_header > >>> *gpt_h, char *str_guid, > >>> gpt_h->signature = cpu_to_le64(GPT_HEADER_SIGNATURE_UBOOT); > >>> gpt_h->revision = cpu_to_le32(GPT_HEADER_REVISION_V1); > >>> gpt_h->header_size = cpu_to_le32(sizeof(gpt_header)); > >>> - gpt_h->my_lba = cpu_to_le64(1); > >>> + gpt_h->my_lba = cpu_to_le64(GPT_PRIMARY_PARTITION_TABLE_LBA); > >>> gpt_h->alternate_lba = cpu_to_le64(desc->lba - 1); > >>> gpt_h->last_usable_lba = cpu_to_le64(desc->lba - 34); > >>> gpt_h->partition_entry_lba = > >> >
