On 2022-02-25 2:42 AM, Pierre-Louis Bossart wrote:
On 2/7/22 06:21, Cezary Rojewski wrote:
ROM requests are messages initiated by Host to alter firmware early boot
process. They specify whether the next boot should be a fresh start or if
IMR can be used to speed things up.
'can' is an imprecise term in technical documentation.
did you mean 'shall' (requirement), 'may' (permission) or 'should'
(recommendation)?
It's my understanding that it's legal to redo a complete reboot from a
clean-slate.
It's also unclear if the firmware can use this mechanism to prevent the
use of IMR, e.g. if in some firmware builds state save/restore was
disabled for some reason.
This is a very good feedback, indeed I miss out on the 'can' vs 'shall'
(and similar) quite often when speaking about hw/fw procedures. Thank
you for paying attention, Pierre.
Yes, in this case driver has total control over the procedure and
chooses which method to use when booting the DSP.
While I can't say the details, closed-source firmware (from APL and
onwards) is built with IMR in mind. By that I mean that it assumes IMR
is always present. So I believe such scenario - having save/restore
disabled - is not possible here.
