Re: [U-Boot] GPT overlap on i.MX6

27 Nov 2019


      Hi Jagan,
...
Hi,
I have created GPT table start from 8MB for kernel, roots etc.
something like
Part    Start LBA       End LBA         Name
        Attributes
        Type GUID
        Partition GUID
  1     0x00004000      0x00023fff      "boota"
        attrs:  0x0000000000000004
        type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
        guid:   c12a7328-f81f-11d2-ba4b-00a0c93ec93b
  2     0x00024000      0x00043fff      "bootb"
        attrs:  0x0000000000000004
        type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
        guid:   21686148-6449-6e6f-744e-656564454649
  3     0x00044000      0x00243fff      "rootfsa"
        attrs:  0x0000000000000000
        type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
        guid:   b921b045-1df0-41c3-af44-4c6f280d3fae
  4     0x00244000      0x00443fff      "rootfsb"
        attrs:  0x0000000000000000
        type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
        guid:   8da63339-0007-60c0-c436-083ac8230908
  5     0x00444000      0x0070bfde      "data"
        attrs:  0x0000000000000000
        type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
        guid:   4f72ab70-69be-5948-81ff-4fc3daf24faa
I have not included SPL, U-Boot to the partition list since it start
from 0x400 in i.MX6. So
I'm writing SPL separately using fastboot(with offset) or ums.
But by doing this, the partition header seems overlapped so the
output looks
GUID Partition Table Entry Array CRC is wrong: 0x6a1aba0a !=
0x8e4fd548 find_valid_gpt: *** ERROR: Invalid GPT ***
find_valid_gpt: ***        Using Backup GPT ***
Part    Start LBA       End LBA         Name
        Attributes
        Type GUID
        Partition GUID
  1     0x00004000      0x00023fff      "boota"
        attrs:  0x0000000000000004
        type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
        guid:   c12a7328-f81f-11d2-ba4b-00a0c93ec93b
  2     0x00024000      0x00043fff      "bootb"
        attrs:  0x0000000000000004
        type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
        guid:   21686148-6449-6e6f-744e-656564454649
  3     0x00044000      0x00243fff      "rootfsa"
        attrs:  0x0000000000000000
        type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
        guid:   b921b045-1df0-41c3-af44-4c6f280d3fae
  4     0x00244000      0x00443fff      "rootfsb"
        attrs:  0x0000000000000000
        type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
        guid:   8da63339-0007-60c0-c436-083ac8230908
  5     0x00444000      0x0070bfde      "data"
        attrs:  0x0000000000000000
        type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
        guid:   4f72ab70-69be-5948-81ff-4fc3daf24faa
So, what I understand is If I create the GPT first and then write the
SPL, the SPL writing process will destroy the GPT Table and if I write
SPL first and then create GPT, the GPT creation process will destroy
the SPL.
Is there any way to fix this? I remember we can prevent this overlap
by preserving GPT Table som other or boot partition instead of having
them at the beginning by default.
Any inputs?
On the diagram of GPT description [1] there is the info that partitions
can start from LBA 34 (0x200 * 34) = 0x4400
From the above it seems like you starts from 0x4000 your boota
partition, which then overwrites the "Entries 5-128" which shall be 0
and are protected by CRC written in the Primary GPT Header.
Please try to adjust your partition scheme to start from 0x4400.
...
Jagan.
Links:
[1] - https://en.wikipedia.org/wiki/GUID_Partition_Table
Best regards,
Lukasz Majewski
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