[U-Boot] [PATCH 17/20] tegra: nyan-big: Add additional clock and kernel init

Stephen Warren swarren at wwwdotorg.org
Thu Feb 26 00:23:13 CET 2015


On 02/17/2015 03:29 PM, Simon Glass wrote:
> We need to turn on all audio-related clocks for the kernel to boot.
> Otherwise it will hang when trying to enable audio.

This certainly isn't true for the upstream kernel; is this some bug in 
the ChromeOS kernel? If so, we should explicitly call this out in the 
commit description.

> Also for Linux set up the ODMDATA and graphics driver video protection.

Why doesn't ODMDATA come from the BCT? The way this is suppose to work 
is that the boot ROM copies the BCT into IRAM, and U-Boot (or indeed any 
bootloader) copies the ODMDATA field from the BCT in IRAM into the PMC 
scratch20 register. This logic is already all in place in U-Boot, and 
indeed any NVIDIA-authored bootloader AFAIK.

Is this U-Boot port intended to run as a Coreboot payload rather than 
natively, and Coreboot is somehow corrupting the copy of the BCT in 
IRAM? If so, we should explicitly call this out in the commit description.

I would personally want to (be able to) make my SPI flash r/w and 
replace Coreboot with U-Boot. Perhaps we need different board names for 
those two use-cases; something like nyan-big for the Coreboot payload, 
and nyan-big-native for the version you'd write directly into SPI?


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