Am 21.01.2013 02:29, schrieb Alexander Holler:
Am 18.01.2013 21:57, schrieb Simon Glass:
Hi,
On Fri, Jan 18, 2013 at 7:47 AM, Steve Strobel steve.strobel@link-comm.com wrote:
Maybe the USB flash drive used for recovery could contain not only the image to be written to flash, but also a bootable OS image used to provide on-screen messages during the recovery process. You would still need the read-only code to provide enough of a UI to boot from the USB flash drive, but the rest of the messages could be generated by that OS.
Yes that's exactly what we do...and yes we still need the read-only code to provide a minimal GUI to get things started. That was the subject of this thread. The recovery mode GUI is provided by a Linux user space tool, but we need to get there first...
Hmm, maybe the kernel people are more open to such an idea. It would just be an additional module/driver and would offer other possible use case too, much more than if such a library would be added to U-Boot.
A minimal kernel is doable with less than 2MB and that Graphics Library could be implemented as module (statically linked) which uses the framebuffer, so no userspace would be necessary at all.
Combined e.g. with lua to use some syscalls for loading files, that could be imho useful for many other task. E.g. to get rid of bootloaders on UEFI systems or to replace initrd's at all (lua in kernel instead of a shell in userspace).
Ok, thats stuff which likely would provoke heated discussions, but at least I would like such. ;)
But something like lua isn't really needed for the above problem. Hardcoding the few steps (e.g. font and picture loading) necessary to lead users to insert an usb-stick is imho a pragmatic solution too. The kernel devs most likely wouldn't want that (because it's not a generic solution), but thats live.
Regards,
Alexander