[PATCH 0/5] rockchip: sdram: allow reading memory info from TPL on non-ARM64

Aaron Griffith aargri at gmail.com
Tue Dec 30 02:59:22 CET 2025


Hello Jonas,

On Mon, Dec 29, 2025 at 08:15:29PM +0100, Jonas Karlman wrote:
> I do not think we want to extend the use of the RK ATAGS, at least not
> unless it is absolutely needed.

Understood, please ignore these patches then.

> The memory size info is also encoded in PMUGRF os_reg2 reg, a simple
> call to rockchip_sdram_size(PMUGRF_BASE + OS_REG2_REG) should be enough
> to get the memory size info typically needed by U-Boot.

I got this working, but I got stuck on the code in
`dram_init_banksize` that tries to read reserved memory from
OP-TEE. When left unmodified it mangles the ram banks and tells Linux
it has 4GB+ of memory. So, I was looking for a way around that.

I was also not aware that it's possible to tell the Rockchip TPL where
to load the SPL. OP-TEE at 0x1000 was giving me a lot of grief.

Besides these two issues, I'm actually quite happy to see that my
branch matches yours pretty well, for my first attempt.

> I have now pushed an updated rk3506 branch to GitHub [1], the old branch
> last rebased in September is located at [2].

Thanks! I'm watching this and the kernel developments closely.

FWIW, I have some Debian images for the Lyra boards [1]. Not very
complicated, but I didn't see any options for Lyra besides the
vendor's SDK. I plan on swapping in upstream sources as they become
ready.

 [1]: https://github.com/agrif/debian-lyra

Thanks,
 -Aaron


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