extboot: Purpose of cmd value
Hi Anthony,
I have to fix extboot for non-KVM usage which means pushing its variables to writable RAM (probably some spare INT vector(s) in the BASIC area).
In that process, I stumbled over the cmd value passed to extboot_init, then stored in qemu_malloc'ed memory, and finally reported to the guest side via port 0x404. It's constant so far, always 1. So there is quite a bit unused code and data on both sides. Can we drop that?
Jan
Signature · 2 lines
Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux
Quoted 11 lines · Jan Kiszka
Hi Anthony,
I have to fix extboot for non-KVM usage which means pushing its variables to writable RAM (probably some spare INT vector(s) in the BASIC area).
In that process, I stumbled over the cmd value passed to
extboot_init, then stored in qemu_malloc'ed memory, and finally reported to the guest side via port0x404. It's constant so far, always 1. So there is quite a bit unused code and data on both sides. Can we drop that?
Yes, that's historic from the days when extboot also did Linux kernel loading. I don't see a problem dropping.
Regards,
Anthony Liguori
Quoted 3 lines
Jan