Hi Alex,
On 10/15/24 2:42 PM, Alex Shumsky wrote:
On Tue, Oct 15, 2024 at 12:34 PM Quentin Schulz quentin.schulz@cherry.de wrote:
I'm wondering if we have somewhere some documentation on the environment variables that exist and what they used for because this would be a nice addition. At the very least, we can mention this variable in:
- include/fdt_support.h for the function
- common/Kconfig for the symbol
I'm not sure if we can expect that all boards can implement the rng_seed_size config knob? Currently rockchip is the only board that implements board_rng_seed.
That;s the neat part, we're the only implementation so far, so we kinda get to say what's supposed to be "standard". I think allowing to get a specific size makes sense generally.
Basically, I would like to avoid 1) people not knowing how to change this value 2) avoid having different implementations using a different environment variable.
Tom has just told me on IRC that we have doc/usage/environment.rst for environment variables' documentation, so that would be a good place to put some documentation for this new variable :)
common/Kconfig BOARD_RNG_SEED description looks rather generic:
It is up to the board code (and more generally the whole BSP) where and how to store (or generate) such a seed, how to ensure a given seed is only used once, how to create a new seed for use on subsequent boots, and whether or not the kernel should account any entropy from the given seed.
I'm also a bit torn on the base though, I think the assumed base is generally hex and not dec, so maybe we should rather have that?
We need a poll here ) Marek Vasut prefers decimal.
Hehe, I think this "debate" will never end, I already had it with Simon and Tom a few weeks ago. The "issue" is that once that's decided, we cannot really change it as that would basically break compatibility (new env with old U-Boot or vice-versa). Not a blocker as such, but needs to make sure it's aligned with expectations.
https://docs.u-boot.org/en/latest/usage/cmdline.html#representing-numbers
Cheers, Quentin