Hi Albin,

On 8/10/26 1:43 PM, Raj, Albin via U-Boot wrote:
Hello,

While testing GPT partitions on USB media, I noticed that partition identifiers 
passed on the command line appear to be parsed as hexadecimal values.

Example:

=> part list usb 0

Partition Map for USB device 0  --   Partition Type: EFI

Part    Start LBA       End LBA         Name
         Attributes
         Type GUID
         Partition GUID
   1     0x00000800      0x008007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   5d33e1b1-c3ae-4e58-8677-13a295ce7b41
   2     0x00800800      0x010007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   277f159b-1239-4be1-bc1e-54c718331584
   3     0x01000800      0x018007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   470b684e-6d99-4a26-866f-14663b13dcbf
   4     0x01800800      0x020007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   1f598bf7-5d31-47bf-9a1d-75c2c6b74dd4
   5     0x02000800      0x028007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   30491f52-e2d7-4f15-8925-92c00ca6e8fb
   6     0x02800800      0x030007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   aef06b97-9320-494b-bff9-3f2cb472ba7f
   7     0x03000800      0x038007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   74143690-f5ab-4437-949e-b098199435c3
   8     0x03800800      0x040007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   fca32ea9-8165-404a-8eac-b22b80a15c8a
   9     0x04000800      0x048007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   fd4d818b-205e-43ef-9de5-7be6bf8550c8
10     0x04800800      0x050007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   a4b21c4c-f0cf-4fb7-b70a-0f191b9fd874
11     0x05000800      0x058007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   243ae3ce-4fd5-4230-ba83-137d8655ea8c
12     0x05800800      0x060007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   671bdeba-dd6a-43e0-a99c-e880ebab991b
13     0x06000800      0x068007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   b5fd6923-e40b-4018-9808-541c91ec81f5
14     0x06800800      0x070007ff      ""
         attrs:  0x0000000000000000
         type:   0fc63daf-8483-4772-8e79-3d69d8477de4
         guid:   29634671-56d8-45f7-8a22-f2b7c33520a5


Partition 9 can be accessed successfully:

=> part uuid usb 0:9
fd4d818b-205e-43ef-9de5-7be6bf8550c8

However:

=> part uuid usb 0:10
** Invalid partition 16 **

=> part uuid usb 0:11
** Invalid partition 17 **

Looking at blk_get_device_part_str() the partition number is parsed with:

     part = (int)hextoul(part_str, &ep);

which converts:

     10 -> 16
     11 -> 17

Since "part list" displays partition identifiers in decimal, users reasonably expect 
"0:10" to refer to partition 10 rather than partition 16.

Is this behavior intentional for backward compatibility, or would decimal 
parsing be preferred?


We will not change the parsing of numbers for existing commands, as you guessed, for backward compatibility. However, we certainly could document it explicitly in https://docs.u-boot-project.org/en/latest/usage/cmd/part.html (which you can change in our source tree in doc/usage/cmd/part.rst).

I think it could also be a good idea to update what "part list" prints to use hex instead of decimal, but I'm not sure everybody will agree.

Cheers,
Quentin

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