[U-Boot] [PATCH v2 2/2] RISCV: image: Parse Image.gz support in booti.

[Atish Patra]

On 4/30/19 2:42 PM, Marek Vasut wrote:
> On 4/30/19 10:38 PM, Atish Patra wrote:
>> On 4/30/19 12:11 PM, Marek Vasut wrote:
>>> On 4/30/19 8:13 PM, Atish Patra wrote:
>>>> On 4/30/19 2:52 AM, Marek Vasut wrote:
>>>>> On 4/30/19 3:27 AM, Atish Patra wrote:
>>>>>
>>>>> [...]
>>>>>
>>>>>>>> Yes. FIT image parsing can be done in that way. However, the idea
>>>>>>>> was
>>>>>>>> here to load Image.gz directly. Image.gz is default compressed Linux
>>>>>>>> kernel image format in RISC-V.
>>>>>>>
>>>>>>> Sigh, and the image header is compressed as well, so there's no
>>>>>>> way to
>>>>>>> identify the image format, right ? And there's no decompressor, so
>>>>>>> the
>>>>>>> dcompressing has to be done by bootloader, which would need some
>>>>>>> sort of
>>>>>>> very smart way of figuring out which exact compression method is
>>>>>>> used ?
>>>>>>>
>>>>>> Yes. Image.gz is always gunzip. So checking first two bytes is
>>>>>> enough to
>>>>>> confirm that it is a gz file.
>>>>>
>>>>> What happens once people start feeding it more exotic compression
>>>>> methods, like LZ4 or LZO or LZMA for example ?
>>>>>
>>>>
>>>> booti command help will clearly state that it can only boot kernel from
>>>> Image or Image.gz.
>>>>
>>>> static char booti_help_text[] =
>>>>        "[addr [initrd[:size]] [fdt]]\n"
>>>> -    "    - boot arm64 Linux Image stored in memory\n"
>>>> +    "    - boot arm64 Linux Image or riscv Linux Image/Image.gz stored
>>>> in memory\n"
>>>
>>> Obvious question -- does this Image.gz stuff apply to arm64 ?
>>>
>>
>> arm64 builds Image.gz but booti for arm64 doesn't use it. I guess
>> Image.gz can be used in FIT image for ARM64 but I am not sure which
>> platform actually uses it.
>>
>> This patch only enables support for RISC-V.
> 
> Can't this be made generic ?
> 

I think so if I just move the gzip detection and decompression code to 
cmd/booti.c.

I will update the v3 patch with this.

Regards,
Atish

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