Messages in this thread | | | Date | Tue, 27 Feb 2024 12:24:09 +0000 | From | Conor Dooley <> | Subject | Re: [PATCH 4/4] riscv: Allow NOMMU kernels to run in S-mode |
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On Mon, Feb 26, 2024 at 04:34:49PM -0800, Samuel Holland wrote: > For ease of testing, it is convenient to run NOMMU kernels in supervisor > mode. The only required change is to offset the kernel load address, > since the beginning of RAM is usually reserved for M-mode firmware. > > Signed-off-by: Samuel Holland <samuel.holland@sifive.com> > --- > > arch/riscv/Kconfig | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index ef53c00470d6..0dc09b2ac2f6 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -64,7 +64,7 @@ config RISCV > select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE > select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU > select BUILDTIME_TABLE_SORT if MMU > - select CLINT_TIMER if !MMU > + select CLINT_TIMER if RISCV_M_MODE > select CLONE_BACKWARDS > select COMMON_CLK > select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND > @@ -220,8 +220,12 @@ config ARCH_MMAP_RND_COMPAT_BITS_MAX > > # set if we run in machine mode, cleared if we run in supervisor mode > config RISCV_M_MODE > - bool > - default !MMU > + bool "Build a kernel that runs in machine mode" > + depends on !MMU > + default y > + help > + Select this option if you want to run the kernel in M-mode, > + without the assistance of any other firmware. > > # set if we are running in S-mode and can use SBI calls > config RISCV_SBI > @@ -238,8 +242,9 @@ config MMU > > config PAGE_OFFSET > hex > - default 0xC0000000 if 32BIT && MMU > - default 0x80000000 if !MMU > + default 0x80000000 if !MMU && RISCV_M_MODE > + default 0x80200000 if !MMU > + default 0xc0000000 if 32BIT > default 0xff60000000000000 if 64BIT
The first default seen with a passing condition is the default chosen, right?
Cheers, Conor. [unhandled content-type:application/pgp-signature] | |