This works by clearing HCR_EL2.TGE, and then doing essentially the same
thunk/return dance as for EL0 calls. However, since most EL1 exceptions
are not routed to EL2, we install hypercall vectors in EL1 to forward
them to EL2, and then short circuit the exception return to whatever
triggered the original exception.
Signed-off-by: Hector Martin <marcan@marcan.st>
This lets us test register access and other features from EL0.
No serious attempt at security is made, but at least EL0 runs off of a
separate stack and can return to EL2 at any time with `brk`; we can
easily implement a guard mode to break straight to EL2 on exception
later if needed.
Signed-off-by: Hector Martin <marcan@marcan.st>
heapblock is a simple `sbrk` style implementation, also useful as an
"endless" decompression buffer. dlmalloc is used on top as a malloc
implementation.
This also changes how the Python side manages its heap. We still use a
python-side malloc implementation (since this is faster), and we put the
Python heap at the m1n1 heap + 128MB, without allocating it.
Hopefully this should never step on anything m1n1 neads, and avoids
having to manage freeing across Python script calls.
Signed-off-by: Hector Martin <marcan@marcan.st>
I saw at least one SError crash on Linux after doing this, but can't
repro; unclear if related to the MMU changes or not...
Signed-off-by: Hector Martin <marcan@marcan.st>
