Hi Andre,
On 1 July 2016 at 04:03, Andre Przywara andre.przywara@arm.com wrote:
Hi,
(sorry if this has been discussed before, feel free to point me to any existing thread then)
for the Pine64 I am looking into letting the SPL load multiple images from a FIT image. Looking at common/spl/spl-fit.c I see that the current SPL FIT support just loads the first image from the "loadables" list as the U-Boot image and then selects and loads the matching FDT right after it. Feature-wise that seems to match what a legacy U-Boot image provides, but I was wondering if anyone uses the multiple images feature that FIT adds to the game?
I need to at least load another image (ARM Trusted Firmware(ATF)), possibly the management controller firmware in the future as well. This has to be done before the actual U-Boot starts, so from the SPL.
So I hacked the code to iterate over all images enumerated in the "loadables" property and load them to their load addresses. That somehow seems to work, but now I was wondering how to make this as flexible as possible:
- How do we know what image is for U-Boot? Shall there be a separate
"uboot" property (next to kernel, loadables, etc)? Or do we stay with the current assumption that it's the first from the loadables list?
That assumption seems reasonable and it is documented in source_file_format.txt. If it causes problems we could adjust this later.
- At the moment we don't honour the entry point. Is there any reason
for that?
Probably because the first user was an FPGA or extra kernel image, which the CPU just has to load.
- Would it be feasible to load all images listed in the loadables
property and then branch to the only one (or the first) that has an entry point property? In my case this would be ATF (which then later drops to U-Boot at its well known load address).
Yes that seems reasonable. Another option would be to add a new entry type instead of using 'firmware'.
I wonder if this has been discussed before and would be grateful if people would share their opinion on the best approach. I will be happy to post patches once we agreed on something.
There has been some discussion recently on ATF with rockchip I think.
Also I've been working on a 'binman' tool which handles the task of actually building firmware images from the build output.
https://www.mail-archive.com/u-boot@lists.denx.de/msg219798.html
Cheers, Andre. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Regards, Simon