On Thu, Aug 22, 2019 at 12:52:41PM +0200, Heinrich Schuchardt wrote: > On 8/22/19 11:11 AM, Mark Kettenis wrote: > >>From: AKASHI Takahiro <[email protected]> > >>Date: Thu, 22 Aug 2019 17:06:25 +0900 > >> > >>Currently, a whole disk without any partitions is not associated > >>with EFI_SIMPLE_FILE_SYSTEM_PROTOCOL. So even if it houses FAT > >>file system, there is a chance that we may not be able to access > >>it, particularly, when accesses are to be attempted after searching > >>that protocol against a device handle. > >> > >>With this patch, EFI_SIMPLE_FILE_SYSTEM_PROTOCOL is installed > >>to such a disk if part_get_info() shows there is not partition > >>table installed on it. > > > >Do other UEFI implementations support this? > > What use cases exist that come without partition table?
I didn't find any *explicit* description in UEFI specification that mandates that any block device should have a partition table. It may be mandatory for boot(able) disks, but for others? > You can create an MBR with partition table that is a valid start of a > file system. Obviously we can do that, but if this is not a mandatory requirement, we'd better support no-partitioned cases. > So you should first check if a partition table exists. Only if none > exists you can test for a possible file system. I don't get your point. Are you saying that we should support a file system for a disk only if it has a file system? This is not true even for existing partitions as FILE_SYSTEM PROTOCOL is always installed to every partition whether or not it really houses a file system under the current implementation. Thanks, -Takahiro Akashi > Best regards > > Heinrich > > > > >>Signed-off-by: AKASHI Takahiro <[email protected]> > >>--- > >> lib/efi_loader/efi_disk.c | 4 +++- > >> 1 file changed, 3 insertions(+), 1 deletion(-) > >> > >>diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c > >>index 7a6b06821a47..548fe667e6f8 100644 > >>--- a/lib/efi_loader/efi_disk.c > >>+++ b/lib/efi_loader/efi_disk.c > >>@@ -239,6 +239,7 @@ static efi_status_t efi_disk_add_dev( > >> struct efi_disk_obj **disk) > >> { > >> struct efi_disk_obj *diskobj; > >>+ disk_partition_t info; > >> efi_status_t ret; > >> > >> /* Don't add empty devices */ > >>@@ -270,7 +271,8 @@ static efi_status_t efi_disk_add_dev( > >> diskobj->dp); > >> if (ret != EFI_SUCCESS) > >> return ret; > >>- if (part >= 1) { > >>+ /* partitions or whole disk without partitions */ > >>+ if (part >= 1 || part_get_info(desc, part, &info)) { > >> diskobj->volume = efi_simple_file_system(desc, part, > >> diskobj->dp); > >> ret = efi_add_protocol(&diskobj->header, > >>-- > >>2.21.0 > >> > >>_______________________________________________ > >>U-Boot mailing list > >>[email protected] > >>https://lists.denx.de/listinfo/u-boot > > > _______________________________________________ U-Boot mailing list [email protected] https://lists.denx.de/listinfo/u-boot
