On Wed, 2025-11-19 at 16:03 +0900, Alexandre Courbot wrote:
> If it comes down to "This is how things are pre and post GA102" (and the
> evidence I have seen to far suggests that unfortunately), then so be it
> - we at the very least encode this as a method of `Chipset` to avoid
> hardcoding chipset versions in several places.
I could add this method to Chipset:
pub(crate) fn supports_dma(&self) -> bool {
*self > Self::GA100
}
But shouldn't this be added to the HAL instead?
There are a few things that are arbitrarily conditional:
1) whether to use PIO or DMA to transfer firmware images to Falcons
2) whether a Generic Bootloader is needed for load FWSEC
3) whether a Non-Secure IMEM section exists
4) what the name of the signature section in the GSP-RM ELF image is
If I'm reading it right, booter.rs currently has no concept of a HAL, which is
why I gated on
Chipset. I agree that doing stuff like
FalconLoadTarget {
src_start: app0.offset,
dst_start: if chipset > Chipset::GA100 { 0 } else {
app0.offset },
len: app0.len,
},
is not ideal. To be honest, it's hard to wrap my head around all of these
offsets. I'm convinced
that most of the confusion is the result of RM developers trying to shoehorn
complex firmware images
into legacy file formats. Just looking at the above:
On Turing, the secure IMEM image is copied from app0.offset in the file to ->
app0.offset (256) in
IMEM.
On Ampere, the secure IMEM image is copied from app0.offset in the file to -> 0
in IMEM.
Why? Apparently, because on Ampere we copy the Secure image to offset 0 and
ignore the Non-Secure
image. On Turing, we copy the Non-Secure image to offset 0 and copy the Secure
image to offset 256.
It would have been much easier to copy the Secure image to 256 on Ampere also,
but that's just not
what happens.
For some reason, os_code_offset and os_code_size contain the same values on
both Turing and Ampere,
but those values are used only on Turing to hold the Non-Secure section. So
the firmware image
headers say that there's a non-secure IMEM section on Ampere, but it's a lie.
