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.
The kernel stack previously was located at the same relative offset as
all other programs. While this worked, it is poor form.
Move the kernel stack into the kernel memory region (located in the last
4 megabytes of virtual address).
Signed-off-by: Sean Cross <sean@xobs.io>
the precursor platform test is a RAM stress test. This patch
improves the test slightly by making it more parameterizeable,
and having it run a bit longer.
this commit adds the facilities to extract eh_frame[_header]
sections and pass it to each process.
A bump is required to `std` to extract the passed parameters.
This is very helpful for debugging loader errors. Basically
it prints out the first and last 20 bytes of each section
based on the source as specified in the MiniElf format, and
then it prints the corresponding data as loaded after walking
the page tables.
Loader errors really stand out with this debugging tool.
it works with e.g. shellchat, but not vault.
still scratching my head on what's gone wrong -- it's
crashing in the pre-boot, which means something is not
mapped right for some case that wasn't caught in the
earlier testing.
Previously, we would unconditionally zero out the remainder of a page
when finished copying. We wrapped to PAGE_SIZE in order to avoid
corrupting another process' memory.
However, an issue was discovered under the following circumstances:
1. There are fewer than 4096 bytes of `.bss`
2. The `.bss` ends on a page boundary
Under these conditions, the loader would load the section before the
`.bss` into the page, then clear out the `.bss`, and finally clear the
entire page, overwriting the previous section.
Skip the remainder-of-page clearout when the `.bss` ends on a page
boundary, rather than clearing the entire page.
Signed-off-by: Sean Cross <sean@xobs.io>
Print out the current process ID when looping through values. This will
make it easier to identify which process is getting loaded when reading
through the tea leaves.
Signed-off-by: Sean Cross <sean@xobs.io>
this helps minimal configurations to be more useful without pulling
in com/llio crates. The trade-off is that KP's early in boot
(or during resume) are not visible, but, these are (thankfully??)
less rare these days.
Add the loader into the main workspace, removing it from its own
sub-workspace. We can do this now that we can specify the linker script
in `build.rs`.
This improves IDE support, and should shrink disk storage requirements.
Signed-off-by: Sean Cross <sean@xobs.io>
- bypass causes warnings to be emitted in compilation
- stark visual change on boot screen ("jail bars" instead of gray on bottom half)
- root keys are locked out permanently from readout
- devboot canary set
