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. 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 = >