The RISC-V boot protocol foresees that at every stage boundary (bootrom
to boot loader, boot loader -> OS), register a0 contains the Hart ID and
a1 contains the physical address of the Flattened Device Tree that the
stage shall use.
As a first step, pass the bootrom-provided FDT to the payload,
unmodified.
Change-Id: I468bc64a47153d564087235f1c7e2d10e3d7a658
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-on: https://review.coreboot.org/23797
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Our toolchain can compile mret now, and once the encoding changes, we'll
have to adjust the code anyway.
Change-Id: Ic37a849f65195006fa15d74f651a8aa9a9da5b5c
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-on: https://review.coreboot.org/21762
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
The riscv 1.9 standard defines a textual config string to be passed
to kernels and hypervisors. Change the payload function to pass
this string in a0.
Change-Id: I3be7f1712accf2d726704e4c970f22749d3c3f36
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: https://review.coreboot.org/17254
Tested-by: build bot (Jenkins)
Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
This version of coreboot successfully starts a Harvey (Plan 9) kernel as a payload,
entering main() with no supporting assembly code for startup. The Harvey port
is not complete so it just panics but ... it gets started.
We provide a standard payload function that takes a pointer argument
and makes the jump from machine to supervisor mode;
the days of kernels running in machine mode are over.
We do some small tweaks to the virtual memory code. We temporarily
disable two functions that won't work on some targets as register
numbers changed between 1.7 and 1.9. Once lowrisc catches up
we'll reenable them.
We add the PAGETABLES to the memlayout.ld and use _pagetables in the virtual
memory setup code.
We now use the _stack and _estack from memlayout so we know where things are.
As time goes on maybe we can kill all the magic numbers.
Change-Id: I6caadfa9627fa35e31580492be01d4af908d31d9
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: https://review.coreboot.org/17058
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>
Jonathan Neuschäfer