Convert the fs_prehash into a hex ascii string, suitable for environment variables
The initial loader environment is hard-coded, so we use a hard-coded offset for the string
destination. It was a deliberate decision to not include a generic environment variable
handler in the loader because we want to keep the loader compact and with a small attack
surface; a generic environment handling routine would add significant size without much
benefit.
Note that the main purpose for environment variables is for test & debug tooling, where
single programs are run in hosted or emulated environments with arguments passed for fast
debugging. The sole purpose for the environment variable in the loader's context is to
this computed hash onto the userspace environments.
Load environment variables to processes by placing the value onto the
stack. This will support additional data in the future such as command
line arguments.
Note this is a breaking change and requires a kernel modification.
Signed-off-by: Sean Cross <sean@xobs.io>
This applies to the *kernel* image.
The loader itself is still signed with the conventional signature.
Version number of the loader is also incremented.
Add the pid as the page owner to `map_page()` calls. This ensures pages
are owned by their respective processes, and removes a lot of
`change_owner()` calls that immediately follow page mapping.
It also allows for superpages to be owned by their respective processes.
Signed-off-by: Sean Cross <sean@xobs.io>
The "susres" page should be owned by the "susres" server and not the
kernel. Avoid mapping this page to the kernel to prevent it from getting
double-mapped.
Signed-off-by: Sean Cross <sean@xobs.io>
Add the pid as the page owner to `map_page()` calls. This ensures pages
are owned by their respective processes, and removes a lot of
`change_owner()` calls that immediately follow page mapping.
It also allows for superpages to be owned by their respective processes.
Signed-off-by: Sean Cross <sean@xobs.io>
The "susres" page should be owned by the "susres" server and not the
kernel. Avoid mapping this page to the kernel to prevent it from getting
double-mapped.
Signed-off-by: Sean Cross <sean@xobs.io>
this might want to get a more graceful feature option wrapped
around it but i'm hoping the unpleasantness of developing on
the FPGA board is...temporary??
When a block of data perfectly fits we fail to allocate the
next page, violating the loop invariant that there's data available
to write.
However, we can't always allocate a new page when we run out
because if we're at the end of the process we shouldn't allocate
a new page (I think). Thus we track if the last section was
a perfect fit, and if it was, we force a new page allocation
before copying more data.
This is an edit in phase 1 of the loader.
in practice this has not been a useful indicator, and we
have stabilized the SVD format so that changes in the code don't
cause the SVD files to go incompatible anymore.
this should make maintenance a bit easier going forward, hopefully.
also merge in cramium support to harmonize the forks for easier
cross-patches in the future.
