On 3/30/22 6:49 PM, Clément Léger wrote:
Le Tue, 22 Mar 2022 13:35:08 +0100, Clément Léger clement.leger@bootlin.com a écrit :
Le Tue, 22 Mar 2022 11:18:39 +0000, Eugen.Hristev@microchip.com a écrit :
[...]
Could not initialize timer (err -22)
...
Could you investigate this please ?
Hi Eugen,
Ok, I'll try to debug that !
Hi Eugen, while debugging it, I found that there was actually one major flaw. The clock that I used was the GLCK. If only this clock is enabled, the TCB can not work, the tcb0_clk must also be enabled for the TCB to start counting. It worked on my side because I forgot that I had a quirk in OP-TEE that was enabling the clocks before starting U-Boot. Without that, it actually could not work.
Since the tcb0_clk is needed, I switched the driver to use this one only and it works well on a "bare" setup (ie without OP-TEE). I even think it could not work with the tcb0_gclk since this one does not correctly handles the case when the parent clock is the slow_clk (which might be the case after booting) and in this case, will return 0 as rate (this is by the way supported in your CCF branch).
Anyway, I fixed the driver to use the tcb0_clk and thus it should work much better. I will send a V8 and it should work with U-Boot and the SPL.
By the way, do you have any documentation which explains how to use U-Boot SPL on sama5d2_xplained (or other) board ?
Hi Clement,
I don't have any documentation at hand, but what I can say in a few words is that once you build the SPL, you should have a file spl/boot.bin and this binary should replace our stage2 at91 bootloader at91bootstrap.
Unlike at91bootstrap, the SPL has all the drivers inside and can boot from all supported media, however, SPL will read a dedicated CPU register where the stage1 has written some bits representing the index of the NVM *used to copy the boot.bin from* . The SPL will then attempt to read the u-boot.bin from the same media. (you can alter the file name in defconfig ).
What is required for your series is that the SPL still works as it worked before your series. (e.g. no regressions with your patches).
Eugen
Regards,
Clément.
-- Clément Léger, Embedded Linux and Kernel engineer at Bootlin https://bootlin.com