[U-Boot] MinnowBoard Turbot U-boot is in 64-bit mode or 32-bit mode

[Simon Glass]

Hi,

On 15 July 2016 at 04:57, vinoth eswaran <evinoth1206 at gmail.com> wrote:
> Hi Mr.Simon Glass,
>
> Currently I am working on an embedded project with Minnowmax Turbot.
>
> I am checking the performance of different compression algorithms that can
> be employed in FIT image. I came across Brotli and felt that it might suit
> my use case.
>
> I had integrated the Brotli to U-Boot and tested the compression algorithm
> performance. It doesn't work as expected and I had contacted the Brotli
> group with the test report:
>
> https://groups.google.com/forum/#!topic/brotli/dg2gNlo61yI
>
> There are certain configurations which I can enable to optimize the
> algorithm,
>
> BROTLI_BUILD_32_BIT disables 64-bit optimizations
> BROTLI_BUILD_64_BIT forces to use 64-bit optimizations
>
> With the BROTLI_BUILD_64_BIT , I am getting the following error messages :
>
> [1.399921 0.114735] 4782061 bytes read in 115 ms (39.7 MiB/s)
> [1.403965 0.004044]    Uncompressing Kernel Image ...
> [1.407913 0.003948]
> [1.407983 0.000070]  brotli decompression start
> [1.411025 0.003042] General Protection
> [1.412884 0.001859] EIP: 0010:[<7b568599>] EFLAGS: 00010002
> [1.416906 0.004022] Original EIP :[<fff13599>]
> [1.419852 0.002946] EAX: 00000001 EBX: 7833e748 ECX: 00000000 EDX: fffffff9
> [1.425035 0.005183] ESI: 00000001 EDI: 01000000 EBP: 7833e848 ESP: 7833e6bc
> [1.430915 0.005880]  DS: 0018 ES: 0018 FS: 0020 GS: 0018 SS: 0018
> [1.435062 0.004147] CR0: 00000033 CR2: 00000000 CR3: 00000000 CR4: 00000600
> [1.440859 0.005797] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
> [1.446064 0.005205] DR6: ffff0ff0 DR7: 00000400
> [1.449103 0.003039] Stack:
> [1.449966 0.000863]     0x7833e6fc : 0x7833e848
> [1.452891 0.002925]     0x7833e6f8 : 0x5c391d06
> [1.455755 0.002864]     0x7833e6f4 : 0x7833fae8
> [1.458056 0.002301]     0x7833e6f0 : 0x7833e750
> [1.461008 0.002952]     0x7833e6ec : 0x7833fae4
> [1.463962 0.002954]     0x7833e6e8 : 0x7833fae0
> [1.466876 0.002914]     0x7833e6e4 : 0xf9ad562e
> [1.469842 0.002966]     0x7833e6e0 : 0x6eb7781b
> [1.472083 0.002241]     0x7833e6dc : 0xe3d562de
> [1.475045 0.002962]     0x7833e6d8 : 0x0756abd8
> [1.477961 0.002916]     0x7833e6d4 : 0x875fabcb
> [1.480914 0.002953]     0x7833e6d0 : 0x957d8f8e
> [1.483862 0.002948]     0x7833e6cc : 0x7b58085f
> [1.486759 0.002897]     0x7833e6c8 : 0x7833e848
> [1.489059 0.002300]     0x7833e6c4 : 0x01000000
> [1.492064 0.003005]     0x7833e6c0 : 0x00000001
> [1.494956 0.002892] --->0x7833e6bc : 0x7833e748
> [1.497860 0.002904]     0x7833e6b8 : 0x00010002
> [1.500719 0.002859]     0x7833e6b4 : 0x00000010
> [1.503109 0.002390]     0x7833e6b0 : 0x7b568599
> [1.505943 0.002834] ### ERROR ### Please RESET the board ###
>

U-Boot is always built in 32-bit mode for x86 at present. I just sent
3 patches to clarify that in the READMEs.

So you can't enable the 64-bit enhancements since the CPU is not in
64-bit mode in U-Boot (at least until the very last moment where it
jumps to Linux if the kernel is 64-bit).

>
> My kernel image is X86_64. I am not sure what is happening in u-boot(32-bit
> or 64-bit). I had gone though the following discussion in U-boot mailing
> list but not understanding what is happening,
>
> http://lists.denx.de/pipermail/u-boot/2016-February/244191.html

Yes, see the patches I just sent. Hopefully it is clearer now.

>
> Mit Freundlichen Grüßen
> VinothKumar
> +49 1798909072

Regards,
Simon