On 16/01/2013 22:46, Simon Glass wrote:
Hi Wolfgang,
Hi Simon,
This sounds like a nice feature. Initially. Then I start wondering if this really belongs into a boot loader. Instead of doing fancy graphics stuff, we should IMO rather focus on booting the OS of your choice really fast, and let this do the fancy GUIs. Or?
The problem is that a major purpose of the GUIs is to allow installing an OS from a USB stick/SD card, since the OS may have become corrupted and unbootable. We have looked at keeping around a separate OS image for this (e.g. in an available disk partition), but so far that hasn't proved practical since that itself can be fairly easily overwritten and we then have a doorstop.
Well, if a separate OS image can be overwritten, U-Boot image can be overwritten too, and then the board does not boot at all.
I provided for a customer a solution with a separate OS and a small rootfs as initramfs, and even if it is theoretically possible to destroy this image, it has the same probability that U-Boot has to disappear. It still seems to me a good solution, with the drawback to use much more resorces (Flash) that a U-Boot solution can use. Anyway, with the current size of NAND flash, even this drawback is not very important in many projects.
Maybe more as a GUI-guided recovery, the customer needs a way to rescue the system when everything goes wrong. Providing a booting SD or USB card, that can complete restore the system, seems to be a good way, or at least it was in my case.
Implementing it in U-Boot seems to me overkilling, but is only my 2 cents ;-).
Best regards, Stefano