[PATCH] disk: part_efi: update partition table entries after write
xypron.glpk at gmx.de
Wed Jan 27 19:50:13 CET 2021
On 1/27/21 7:33 AM, AKASHI Takahiro wrote:
> On Tue, Jan 26, 2021 at 04:08:13PM +0100, Heinrich Schuchardt wrote:
>> On 26.01.21 14:56, Gary Bisson wrote:
>>> Fixes fastboot issues when switching from mbr to gpt partition tables.
>>> Signed-off-by: Gary Bisson <gary.bisson at boundarydevices.com>
>>> I hesitated calling this a RFC as I'm not sure everyone will like the
>>> Basically the issue encountered was the following:
>>> - Device with its storage flashed with a MBR partition table
>>> - Run fastboot to flash a new OS (and new partition table)
>>> - After flashing a GPT partition table, U-Boot couldn't find any of the
>>> partition names from the GPT
>>> -> reason is that the partition table entries aren't updated
>>> -> so U-Boot still believes it's a MBR table inside and so its parsing
>>> This commit adds an update of the table entries inside the
>>> write_mbr_and_gpt_partitions() function. At first I thought maybe this
>>> should be added in fastboot file (fb_mmc.c) but couldn't think of a good
>>> reason why this shouldn't happened in part_efi directly.
>>> Let me know if you have any questions.
>>> disk/part_efi.c | 3 +++
>>> 1 file changed, 3 insertions(+)
>>> diff --git a/disk/part_efi.c b/disk/part_efi.c
>>> index 2f922662e6e..7a24e33d189 100644
>>> --- a/disk/part_efi.c
>>> +++ b/disk/part_efi.c
>>> @@ -867,6 +867,9 @@ int write_mbr_and_gpt_partitions(struct blk_desc *dev_desc, void *buf)
>>> return 1;
>>> + /* Update the partition table entries*/
>>> + part_init(dev_desc);
>>> return 0;
>> This change is for GPT only. Don't we need the same for MBR partition
>> tables (write_mbr_partitions())?
>> Essentially this reflashing is similar to changing media. What I am
>> missing in part_init() is setting a field with a counter to indicate the
>> media change. The EFI_BLOCK_IO_PROTOCOL has a u32 field media_id. Would
>> struct blk_desc be the right place to add such a field.
> As far as "efi_loader" is concerned, none of partitions on the media,
> either in case of repartitioning or changing media, will no longer be
> recognized as a "efi disk" after efi subsystem is initialized.
> All we can and have to do is to just reboot the system.
> I think we should take one step further to fixing the issue along with
> this patch. I have posted a couple of proposals in the past, for example,
> see .
>  https://lists.denx.de/pipermail/u-boot/2019-January/356499.html
We have a deficiency in the UEFI sub-system with adding and removing
block devices. But this is not a problem of Gary's patch.
So from my side:
Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
More information about the U-Boot