Re: [Qemu-devel] [PATCH] pc-bios/s390-ccw: build s390 bios with -fno-zero-initialized-in-bss

[Christian Borntraeger]

On 11/20/2017 10:19 AM, Alexander Graf wrote:
> On 11/20/2017 10:15 AM, Christian Borntraeger wrote:
>> The QEMU ELF loader does not initialize the bss segment. This has
>> triggered several bugs in the past, e.g. see commit 5d739a4787a5
>> ("s390-ccw.img: Fix sporadic errors with ccw boot image - initialize
>> css").
>>
>> Instead of fixing these things one-by-one we can build the BIOS
>> with -fno-zero-initialized-in-bss. This will move the zero variables
>> also into the data segment, which is then part of a LOAD section.
> 
> Doesn't this bloat the firmware? Why don't we just manually clear bss in the 
> firmware itself? It's what all other firmwares do :)

Yes the proper fix is to initialize bss in the bios itself.
I was trying to come up with something for 2.11, but since the patch does not 
solve the original issues, lets drop it.