Re: [PATCH v2 1/1] OvmfPkg: Introduce 16MiB flash size for (primarily) Linuxboot

["Devon Bautista" <dbautista@newmexicoconsortium.org>]

On 9/3/21 12:17 AM, Gerd Hoffmann wrote:
> On Fri, Sep 03, 2021 at 05:26:20AM +0000, Devon Bautista wrote:
>> The largest size flash image currently available for OVMF builds, 4MiB,
>> is too small to insert a Linux kernel and initramfs into the DXEFV, and
>> is thus insufficient for testing Linuxboot builds via OVMF.
> 
>>   FVMAIN_COMPACT             uncompressed        3360 -> 15648 (+12288)
>>     FV FFS file              LZMA compressed
>>       PEIFV                  uncompressed         896 ->   896 (    +0)
>>         individual PEI       uncompressed
>>           modules
>>       DXEFV                  uncompressed       12288 -> 12288 (    +0)
>>         individual DXE       uncompressed
>>           modules
> 
> Patch looks sane to me.
> 
> Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
> 
Thank you for your review.

> How you are going to use the extra space you got?
> Do you add kernel + initrd as ffs files to FVMAIN_COMPACT?
> 
> take care,
>   Gerd
> 
The kernel + initrd are added as an application in DXEFV, and a
"linuxboot" DXE driver is added that dispatches the bzImage.

The Linuxboot build system tries to remove some of the DXE drivers that
are redundant to Linux drivers, but even after this there is still not
enough room to insert the kernel + initrd with the 4MiB build target,
even with XZ kernel and initrd compression.

Best,
Devon