[U-Boot] ** Can't read Driver Desriptor Block **

[Heinrich Schuchardt]

On 08/30/2017 06:37 AM, Heinrich Schuchardt wrote:
> 
> 
> On 08/30/2017 03:54 AM, Bin Meng wrote:
>> Hi Heinrich,
>>
>> On Wed, Aug 30, 2017 at 4:26 AM, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>>> Hello Simon,
>>>
>>> U-Boot HEAD qemu-86_defconfig cannot discover an IDE disk with one FAT
>>> partition in qemu-system-x86_64.
>>>
>>> By bisection I found this patch.
>>>
>>> b7c6baef2891ce8978cbfddb66e944943473ac21
>>> x86: Convert MMC to driver model
>>>
>>> With this patch I get
>>>
>>> IDE:   Bus 0: OK Bus 1: OK
>>>   Device 0: Model: QEMU HARDDISK  Firm: 2.5+ Ser#: QM00001
>>>             Type: Hard Disk
>>>             Supports 48-bit addressing
>>>             Capacity: 128.0 MB = 0.1 GB (262144 x 512)
>>> ** Can't read Driver Desriptor Block **
>>>   Device 1: not available
>>>   Device 2: Model: QEMU Firm: 2.5+ Ser#: QEMU DVD-ROM
>>>             Type: Removable CD ROM
>>>             Capacity: not available
>>>   Device 3: not available
>>>
>>> => ide info
>>> =>
>>>
>>> Without the patch I get=> ide info
>>> Device 0: Model: QEMU HARDDISK  Firm: 2.5+ Ser#: QM00001
>>>             Type: Hard Disk
>>>             Supports 48-bit addressing
>>>             Capacity: 128.0 MB = 0.1 GB (262144 x 512)
>>> Device 2: Model: QEMU Firm: 2.5+ Ser#: QEMU DVD-ROM
>>>             Type: Removable CD ROM
>>>             Capacity: not available
>>>
>>> I think we observe two independent errors here:
>>>
>>> - The hard disk Device 0 is not read.
>>> - The ide command stops at the first device that is not available.
>>>
>>> I guess only the first is caused by your patch.
>>
>> Both logs look fine to me. The "Can't read Driver Desriptor Block"
>> comes from part_mac.c. Did you verify the actual IDE read/write fails
>> with current HEAD?
>>
>> Regards,
>> Bin
>>
> 
> Hello Bin,
> 
> I have not checked block level read but used the shell commands for testing.
> 
> Before the patch I can read the directory of the drive:
> 
> => ide info
> Device 0: Model: QEMU HARDDISK  Firm: 2.5+ Ser#: QM00001
>             Type: Hard Disk
>             Supports 48-bit addressing
>             Capacity: 128.0 MB = 0.1 GB (262144 x 512)
> Device 2: Model: QEMU Firm: 2.5+ Ser#: QEMU DVD-ROM
>             Type: Removable CD ROM
>             Capacity: not available
> => fat2ls ide 0:1
> Unknown command 'fat2ls' - try 'help'
> => fatls ide 0:1
>    164768   snp.efi
>         0   file1
>         0   file2
> 
> 
> After the patch (including HEAD) I cannot read the directory and cannot
> load the file snp.efi either:
> 
> => ide info
> => fatls ide 0:1
> ** Bad device ide 0 **
> =>
> => fatls mmc 0:1
> ** Bad device mmc 0 **
> 
> 
> In both cases I have loaded the same image with:
> 
> export BUILD_ROM=y
> make distclean && make qemu-x86_defconfig && make -j6
> 
> qemu-system-x86_64 -m 1G -bios u-boot.rom -nographic \
> -netdev \
> user,id=eth0,tftp=tftp,net=192.168.76.0/24,dhcpstart=192.168.76.9 \
> -device e1000,netdev=eth0 -machine pc-i440fx-2.8 -hda img
> 
> Best regards
> 
> Heinrich
> 

Hello Bin, hello Simon,

I think the bug is in functions ide_init (drivers/block/ide.c).

Platform X86 implies CONFIG_BLK=y.

So we should initialize ide_dev_desc[i].bdev.

We don't, so blk_dread fails after finding no read operation with ENOSYS
when called from part_test_dos.

The following comment in include/blk.h confirms that bdev has to be filled:

#if CONFIG_IS_ENABLED(BLK)
/*
* For now we have a few functions which take struct blk_desc as a
* parameter. This field allows them to look up the associated
* device. Once these functions are removed we can drop this field.
*/
struct udevice *bdev;
#else

I assume that we have the same issue in in __sata_initialize
(drivers/ata/sata.c) but have not tested.

Best regards

Heinrich