On Thu, 12 Feb 2026 at 22:45, Javier Martinez Canillas <[email protected]> wrote: > > Refactor the part_get_info_extended() helper function (which already > recursively traverses DOS partitions) to optionally return the raw MBR > partition structure (dos_partition_t). > > This allows other subsystems, such as EFI, to retrieve the partition > details in the legacy MBR format. > > Signed-off-by: Javier Martinez Canillas <[email protected]> > ---
Reviewed-by: Ilias Apalodimas <[email protected]> > > (no changes since v1) > > disk/part_dos.c | 66 ++++++++++++++++++++++++++++++------------------- > include/part.h | 14 +++++++++++ > 2 files changed, 55 insertions(+), 25 deletions(-) > > diff --git a/disk/part_dos.c b/disk/part_dos.c > index a69ad8962106..4e1d01b2f21e 100644 > --- a/disk/part_dos.c > +++ b/disk/part_dos.c > @@ -204,7 +204,8 @@ static void print_partition_extended(struct blk_desc > *desc, > * @relative: Relative offset for the partition > * @part_num: Current partition number > * @which_part: Target partition number > - * @info: Returns a pointer to the partition info > + * @info: Returns partition information (optional) > + * @mbr: Returns MBR partition entry (optional) > * @disksig: Disk signature > * > * Return: 0 on success, negative on error > @@ -212,7 +213,9 @@ static void print_partition_extended(struct blk_desc > *desc, > static int part_get_info_extended(struct blk_desc *desc, > lbaint_t ext_part_sector, lbaint_t relative, > int part_num, int which_part, > - struct disk_partition *info, uint disksig) > + struct disk_partition *info, > + dos_partition_t *mbr, > + uint disksig) > { > ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, desc->blksz); > struct disk_partition wdinfo = { 0 }; > @@ -243,9 +246,11 @@ static int part_get_info_extended(struct blk_desc *desc, > if (CONFIG_IS_ENABLED(PARTITION_UUIDS) && !ext_part_sector) > disksig = > get_unaligned_le32(&buffer[DOS_PART_DISKSIG_OFFSET]); > > - ret = part_get_info_whole_disk(desc, &wdinfo); > - if (ret) > - return ret; > + if (info) { > + ret = part_get_info_whole_disk(desc, &wdinfo); > + if (ret) > + return ret; > + } > > /* Print all primary/logical partitions */ > pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET); > @@ -258,25 +263,29 @@ static int part_get_info_extended(struct blk_desc *desc, > (pt->sys_ind != 0) && > (part_num == which_part) && > (ext_part_sector == 0 || is_extended(pt->sys_ind) == 0)) { > - if (wdinfo.blksz > DOS_PART_DEFAULT_SECTOR) > - info->blksz = wdinfo.blksz; > - else > - info->blksz = DOS_PART_DEFAULT_SECTOR; > - info->start = (lbaint_t)(ext_part_sector + > - get_unaligned_le32(&pt->start_sect)); > - info->size = > (lbaint_t)get_unaligned_le32(&pt->nr_sects); > - part_set_generic_name(desc, part_num, > - (char *)info->name); > - /* sprintf(info->type, "%d, pt->sys_ind); */ > - strcpy((char *)info->type, "U-Boot"); > - info->bootable = get_bootable(pt); > - if (CONFIG_IS_ENABLED(PARTITION_UUIDS)) { > - char str[12]; > - > - sprintf(str, "%08x-%02x", disksig, part_num); > - disk_partition_set_uuid(info, str); > + if (info) { > + if (wdinfo.blksz > DOS_PART_DEFAULT_SECTOR) > + info->blksz = wdinfo.blksz; > + else > + info->blksz = DOS_PART_DEFAULT_SECTOR; > + info->start = (lbaint_t)(ext_part_sector + > + > get_unaligned_le32(&pt->start_sect)); > + info->size = > (lbaint_t)get_unaligned_le32(&pt->nr_sects); > + part_set_generic_name(desc, part_num, > + (char *)info->name); > + /* sprintf(info->type, "%d, pt->sys_ind); */ > + strcpy((char *)info->type, "U-Boot"); > + info->bootable = get_bootable(pt); > + if (CONFIG_IS_ENABLED(PARTITION_UUIDS)) { > + char str[12]; > + > + sprintf(str, "%08x-%02x", disksig, > part_num); > + disk_partition_set_uuid(info, str); > + } > + info->sys_ind = pt->sys_ind; > } > - info->sys_ind = pt->sys_ind; > + if (mbr) > + memcpy(mbr, pt, sizeof(*mbr)); > return 0; > } > > @@ -296,7 +305,8 @@ static int part_get_info_extended(struct blk_desc *desc, > > return part_get_info_extended(desc, lba_start, > ext_part_sector == 0 ? lba_start : relative, > - part_num, which_part, info, disksig); > + part_num, which_part, > info, > + mbr, disksig); > } > } > > @@ -328,7 +338,13 @@ static void __maybe_unused part_print_dos(struct > blk_desc *desc) > static int __maybe_unused part_get_info_dos(struct blk_desc *desc, int part, > struct disk_partition *info) > { > - return part_get_info_extended(desc, 0, 0, 1, part, info, 0); > + return part_get_info_extended(desc, 0, 0, 1, part, info, NULL, 0); > +} > + > +int __maybe_unused part_get_mbr(struct blk_desc *desc, int part, > + dos_partition_t *mbr) > +{ > + return part_get_info_extended(desc, 0, 0, 1, part, NULL, mbr, 0); > } > > int is_valid_dos_buf(void *buf) > diff --git a/include/part.h b/include/part.h > index daebbbc2e68f..aed089d00f64 100644 > --- a/include/part.h > +++ b/include/part.h > @@ -704,6 +704,20 @@ int write_mbr_partitions(struct blk_desc *dev, > int layout_mbr_partitions(struct disk_partition *p, int count, > lbaint_t total_sectors); > > +/** > + * part_get_mbr() - get the MBR partition record of a partition > + * > + * This function reads the MBR partition record for a given block > + * device and partition number. > + * > + * @desc: block device descriptor > + * @part: partition number for which to return the partition record > + * @mbr: MBR partition record > + * > + * Return: 0 on success, otherwise error > + */ > +int part_get_mbr(struct blk_desc *desc, int part, dos_partition_t *mbr); > + > #endif > > #if CONFIG_IS_ENABLED(PARTITIONS) > -- > 2.53.0 >
