Heinrich, On Fri, Aug 23, 2019 at 09:04:21AM +0900, AKASHI Takahiro wrote: > 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.
Any further comments? -Takahiro Akashi > > > 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
