these currently only make sense in a simulation environment,
but they allow us to work the significant configuration test
cases for practical execution to make sure we haven't missed
something in the coreuser spec.
- updates enables or disables updates in the loader
- verilator-only will turn off routines that access hardware not
present in verilator (e.g. leads to a bus lockup)
- simulation-only turns of features that take a long amount of time
and aren't necessary in simulation, such as bulk clearing of
all RAM - in simulation, we can configure the simulator to do this
for us prior to boot; but in HW, of course, RAM is just random,
or worse, has the previous session's secrets in it.
not quite sure why it is even there, might just be a thing from
really old code we never removed. Removing this allows us to
specify pointer types to non-copy elements, making Rust do
the hard work of figuring out how big of a block we need to zero.
because the print! macro becomes a dummy when debug printing is
off, we get a bunch of warnings about unused variables because
the print! arguments aren't used. Add _ before variable names
to quiet these warnings.
trying to condense most of the RPT API into the loader so
that the userspace can use a single dependency for this.
We can't condense the kernel API into the loader unfortunately,
because the kernel actually uses a different type for representing
a process. This is probably a mistake, and is something that
may be fixed later so we can merge the representations.
We had a "coincidence" before that allowed things to work,
where we had some data line up that we happened to think
was some other header data, so we "fixed" it by
subtracting the offset of the header data.
Actually, it wasn't.
Clarify that decrypt_src_page_at() offsets are relative
to the beginning of encrypted data, and not relative
to the absolute beginning of the disk.
Image creation is now fixed so that stuff lines up to what
this routine expects, and some asserts added to try and
save ourselves in the future as we try to fix other bugs
we discover over time.
loaders are hard.
this is more robust, and should work across all architectures.
Note that the reliability of the check is slightly impacted
since we're now checking for a subset of valid numbers, so
the number of bytes checked is doubled.
In swap configuration, the loader does a lot more: it has
to decrypt full pages of RAM and hold them temporarily;
up to two pages at once, once for the decrypt of the source
swap image, and one for the encrypt to swap memory.
This causes a lot more stack to be used than the original loader.
Add some debugging for this, and an assert based on a heuristic
that the RPT (runtime page tracker) last few entries ought to
be 0. This I think is probably true on most platforms. If this
fails to be true, then, we can probably modify the assert to
fail if any number in the RPT is greater than the number of
processes: this should be true in *all* cases, but a stack smash
is very likely to write something in there that's larger than
the number of allowable processes in the system.
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.
