fsl_hash.c: Alignment problem when using caam_hash() for FIT images

fsl_hash.c: Alignment problem when using caam_hash() for FIT images

[Stefan Roese]

Hi,

while working on an LX2160 based board and updating to latest mainline
I noticed problems using the HW accelerated hash functions on this
platform, when trying to boot a FIT Kernel image. Here the resulting
error message:

## Loading kernel from FIT Image at a0000000 ...
    Using 'conf-freescale_lx2160a.dtb' configuration
    Trying 'kernel-1' kernel subimage
    Verifying Hash Integrity ... sha256Error: Address arguments are not 
aligned
CAAM was not setup properly or it is faulty
  error!
Bad hash value for 'hash-1' hash node in 'kernel-1' image node
Bad Data Hash
ERROR: can't get kernel image!

And here the addresses, printed from caam_hash():
caam_hash (171): pbuf=00000000a00000fc pout=00000000fbde6f80 
buf_len=5291241 ARCH_DMA_MINALIGN=64

pbuf points to an area in the FIT image itself. So its not easy
to change this.

In some quick tests I've dropped the alignment check and have not seen
any problems yet. The hash is calculated without any problems and seems
to be okay. I might be just lucky though, not sure.

So my basic question is: Is this alignment really necessary and required
for both addresses in this function?

If yes, do you have some suggestions on how to handle this? Other than
allocating new aligned buffers in caam_hash() and memcpy'ing to those
new buffers instead. BTW, this is not a preferred solution for me, as
boot-time is crucial for my platform.

Thanks,
Stefan

RE: [EXT] fsl_hash.c: Alignment problem when using caam_hash() for FIT images

[Gaurav Jain]

Hello Stefan

> -----Original Message-----
> From: Stefan Roese <sr@denx.de>
> Sent: Friday, April 29, 2022 6:24 PM
> To: U-Boot Mailing List <u-boot@lists.denx.de>
> Cc: Gaurav Jain <gaurav.jain@nxp.com>; 'dullfire@yahoo.com
> Subject: [EXT] fsl_hash.c: Alignment problem when using caam_hash() for FIT
> images
> 
> Caution: EXT Email
> 
> Hi,
> 
> while working on an LX2160 based board and updating to latest mainline I
> noticed problems using the HW accelerated hash functions on this platform,
> when trying to boot a FIT Kernel image. Here the resulting error message:
> 
> ## Loading kernel from FIT Image at a0000000 ...
>     Using 'conf-freescale_lx2160a.dtb' configuration
>     Trying 'kernel-1' kernel subimage
>     Verifying Hash Integrity ... sha256Error: Address arguments are not aligned
> CAAM was not setup properly or it is faulty
>   error!
> Bad hash value for 'hash-1' hash node in 'kernel-1' image node Bad Data Hash
> ERROR: can't get kernel image!
> 
> And here the addresses, printed from caam_hash():
> caam_hash (171): pbuf=00000000a00000fc pout=00000000fbde6f80
> buf_len=5291241 ARCH_DMA_MINALIGN=64
> 
> pbuf points to an area in the FIT image itself. So its not easy to change this.
> 
> In some quick tests I've dropped the alignment check and have not seen any
> problems yet. The hash is calculated without any problems and seems to be okay.
> I might be just lucky though, not sure.
> 
> So my basic question is: Is this alignment really necessary and required for both
> addresses in this function?
You are right, Alignment is not necessary and can be removed.
> 
> If yes, do you have some suggestions on how to handle this? Other than
> allocating new aligned buffers in caam_hash() and memcpy'ing to those new
> buffers instead. BTW, this is not a preferred solution for me, as boot-time is
> crucial for my platform.
> 
> Thanks,
> Stefan

Re: [EXT] fsl_hash.c: Alignment problem when using caam_hash() for FIT images

[Stefan Roese]

On 4/29/22 15:22, Gaurav Jain wrote:
> Hello Stefan
> 
>> -----Original Message-----
>> From: Stefan Roese <sr@denx.de>
>> Sent: Friday, April 29, 2022 6:24 PM
>> To: U-Boot Mailing List <u-boot@lists.denx.de>
>> Cc: Gaurav Jain <gaurav.jain@nxp.com>; 'dullfire@yahoo.com
>> Subject: [EXT] fsl_hash.c: Alignment problem when using caam_hash() for FIT
>> images
>>
>> Caution: EXT Email
>>
>> Hi,
>>
>> while working on an LX2160 based board and updating to latest mainline I
>> noticed problems using the HW accelerated hash functions on this platform,
>> when trying to boot a FIT Kernel image. Here the resulting error message:
>>
>> ## Loading kernel from FIT Image at a0000000 ...
>>      Using 'conf-freescale_lx2160a.dtb' configuration
>>      Trying 'kernel-1' kernel subimage
>>      Verifying Hash Integrity ... sha256Error: Address arguments are not aligned
>> CAAM was not setup properly or it is faulty
>>    error!
>> Bad hash value for 'hash-1' hash node in 'kernel-1' image node Bad Data Hash
>> ERROR: can't get kernel image!
>>
>> And here the addresses, printed from caam_hash():
>> caam_hash (171): pbuf=00000000a00000fc pout=00000000fbde6f80
>> buf_len=5291241 ARCH_DMA_MINALIGN=64
>>
>> pbuf points to an area in the FIT image itself. So its not easy to change this.
>>
>> In some quick tests I've dropped the alignment check and have not seen any
>> problems yet. The hash is calculated without any problems and seems to be okay.
>> I might be just lucky though, not sure.
>>
>> So my basic question is: Is this alignment really necessary and required for both
>> addresses in this function?
> You are right, Alignment is not necessary and can be removed.

Perfect, thanks. Let me generate a patch for this. Stay tuned... ;)

Thanks,
Stefan

>>
>> If yes, do you have some suggestions on how to handle this? Other than
>> allocating new aligned buffers in caam_hash() and memcpy'ing to those new
>> buffers instead. BTW, this is not a preferred solution for me, as boot-time is
>> crucial for my platform.
>>
>> Thanks,
>> Stefan

Viele Grüße,
Stefan Roese

-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email: sr@denx.de

Re: fsl_hash.c: Alignment problem when using caam_hash() for FIT images

[Sean Anderson]

Hi Stefan,

On 4/29/22 8:54 AM, Stefan Roese wrote:
> Hi,
> 
> while working on an LX2160 based board and updating to latest mainline
> I noticed problems using the HW accelerated hash functions on this
> platform, when trying to boot a FIT Kernel image. Here the resulting
> error message:
> 
> ## Loading kernel from FIT Image at a0000000 ...
>    Using 'conf-freescale_lx2160a.dtb' configuration
>    Trying 'kernel-1' kernel subimage
>    Verifying Hash Integrity ... sha256Error: Address arguments are not aligned
> CAAM was not setup properly or it is faulty
>  error!
> Bad hash value for 'hash-1' hash node in 'kernel-1' image node
> Bad Data Hash
> ERROR: can't get kernel image!
> 
> And here the addresses, printed from caam_hash():
> caam_hash (171): pbuf=00000000a00000fc pout=00000000fbde6f80 buf_len=5291241 ARCH_DMA_MINALIGN=64
> 
> pbuf points to an area in the FIT image itself. So its not easy
> to change this.
> 
> In some quick tests I've dropped the alignment check and have not seen
> any problems yet. The hash is calculated without any problems and seems
> to be okay. I might be just lucky though, not sure.
> 
> So my basic question is: Is this alignment really necessary and required
> for both addresses in this function?
> 
> If yes, do you have some suggestions on how to handle this? Other than
> allocating new aligned buffers in caam_hash() and memcpy'ing to those
> new buffers instead. BTW, this is not a preferred solution for me, as
> boot-time is crucial for my platform.

Use -EB 0x40 when generating your image. This will use "external" data
(e.g. not within the dtb) which is aligned to 64 bytes.

--Sean