[PATCH v8] RISC-V: enable XIP

[Palmer Dabbelt]

On Tue, 27 Apr 2021 20:08:24 PDT (-0700), linux at roeck-us.net wrote:
> On Tue, Apr 13, 2021 at 02:35:14AM -0400, Alexandre Ghiti wrote:
>> From: Vitaly Wool <vitaly.wool at konsulko.com>
>>
>> Introduce XIP (eXecute In Place) support for RISC-V platforms.
>> It allows code to be executed directly from non-volatile storage
>> directly addressable by the CPU, such as QSPI NOR flash which can
>> be found on many RISC-V platforms. This makes way for significant
>> optimization of RAM footprint. The XIP kernel is not compressed
>> since it has to run directly from flash, so it will occupy more
>> space on the non-volatile storage. The physical flash address used
>> to link the kernel object files and for storing it has to be known
>> at compile time and is represented by a Kconfig option.
>>
>> XIP on RISC-V will for the time being only work on MMU-enabled
>> kernels.
>>
>> Signed-off-by: Alexandre Ghiti <alex at ghiti.fr> [ Rebase on top of "Move
>> kernel mapping outside the linear mapping" ]
>> Signed-off-by: Vitaly Wool <vitaly.wool at konsulko.com>
>> Reported-by: Naresh Kamboju <naresh.kamboju at linaro.org>
>
> In next-20210426, when building riscv:allnoconfig or riscv:tinyconfig:
>
> arch/riscv/kernel/setup.c: In function 'setup_arch':
> arch/riscv/kernel/setup.c:284:32: error: implicit declaration of function 'XIP_FIXUP'

Sorry about that.  I thought I'd fixed the last build, but I guess I 
managed to just miss these build failures in a spew of successes.  I 
just sent out a patch to fix it.