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author | Jordan Niethe <jniethe5@gmail.com> | 2022-07-12 10:46:24 +1000 |
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committer | Alexey Kardashevskiy <aik@ozlabs.ru> | 2022-07-19 12:54:08 +1000 |
commit | b3f699c06ac03909d4af11806f3450092cde60ee (patch) | |
tree | 231cb5c023145802d31a5b9c0c2900e834a9f549 /board-qemu | |
parent | 5b4c5acdcd552a4e1796aeca6bb700f6cbb0282d (diff) | |
download | SLOF-b3f699c06ac03909d4af11806f3450092cde60ee.zip SLOF-b3f699c06ac03909d4af11806f3450092cde60ee.tar.gz SLOF-b3f699c06ac03909d4af11806f3450092cde60ee.tar.bz2 |
OF: Add a separate direct kernel loading word
Currently, go-64 is used for booting a kernel from qemu (i.e. -kernel).
However, there is an expectation from users that this should be able to
boot not just vmlinux kernels but things like Zimages too.
The bootwrapper of a BE zImage is a 32-bit ELF. Attempting to load that
with go-64 means that it will be ran with MSR_SF set (64-bit mode). This
crashes early in boot (usually due to what should be 32-bit operations
being done with 64-bit registers eventually leading to an incorrect
address being generated and branched to).
Note that our 64-bit payloads are prepared to enter with MSR_SF cleared
and set it themselves very early.
Add a new word named go-direct that will execute any simple payload
in-place and will enter with MSR_SF cleared. This allows booting a BE
zImage from qemu with -machine kernel-addr=0.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Diffstat (limited to 'board-qemu')
-rw-r--r-- | board-qemu/slof/OF.fs | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/board-qemu/slof/OF.fs b/board-qemu/slof/OF.fs index f0fc9c6..3bcb2af 100644 --- a/board-qemu/slof/OF.fs +++ b/board-qemu/slof/OF.fs @@ -303,10 +303,9 @@ set-default-console : (boot-ram) direct-ram-boot-size 0<> IF ." Booting from memory..." cr - s" go-args 2@ " evaluate - direct-ram-boot-base 0 + s" direct-ram-boot-base to go-entry" evaluate s" true state-valid ! " evaluate - s" disable-watchdog go-64" evaluate + s" disable-watchdog go-direct" evaluate THEN ; |