arm64: head: create a temporary FDT mapping in the initial ID map

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We need to access the DT very early to get at the command line and the
KASLR seed, which currently means we rely on some hacks to call into the
kernel before really calling into the kernel, which is undesirable.

So instead, let's create a mapping for the FDT in the initial ID map,
which is feasible now that it has been extended to cover more than a
single page or block, and can be updated in place to remap other output
addresses.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220624150651.1358849-15-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

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Ard Biesheuvel 2022-06-24 17:06:44 +02:00 • committed by Will Deacon

parent d7bea55027

commit f70b3a2332

2 changed files with 17 additions and 3 deletions

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6

arch/arm64/include/asm/kernel-pgtable.h

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14

arch/arm64/kernel/head.S

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