On Sun, 2020-01-26 at 17:24 -0500, Sean Anderson wrote: > On 1/26/20 5:09 PM, Lukas Auer wrote: > > + Bin, Anup, Atish > > > > > > On Wed, 2020-01-15 at 17:53 -0500, Sean Anderson wrote: > > > On the kendryte k210, writes to mcounteren result in an illegal > > > instruction > > > exception. > > > > > > Signed-off-by: Sean Anderson <sean...@gmail.com> > > > --- > > > Changes for v2: > > > Moved forward in the patch series > > > > > > arch/riscv/Kconfig | 3 +++ > > > arch/riscv/cpu/cpu.c | 2 ++ > > > 2 files changed, 5 insertions(+) > > > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > > index 9a7b0334c2..4f8c62dcff 100644 > > > --- a/arch/riscv/Kconfig > > > +++ b/arch/riscv/Kconfig > > > @@ -226,6 +226,9 @@ config XIP > > > from a NOR flash memory without copying the code to ram. > > > Say yes here if U-Boot boots from flash directly. > > > > > > +config SYS_RISCV_NOCOUNTER > > > + bool "Disable accesses to the mcounteren CSR" > > > + > > > > Can you rename this to something like RISCV_PRIV_1_9_1? > > > > The k210 implements version 1.9.1 of the privileged spec (if I remember > > correctly). The mcounteren CSR doesn't exist in that version and > > therefore triggers the illegal instruction exception. By renaming the > > config entry, it is clearer why the CSR is missing and is therefore not > > accessed. > > Thanks, I was not aware that the k210 was following a different spec > when I made the change. For v3 I can add this functionality back using > the old counter CSRs. > > > I am not too familiar with the changes between the versions of the > > spec. Are there other parts of the code we need to adapt? > > From reading the changelog, most of the changes seem related to virtual > memory, which doesn't apply to u-boot. >
Ok, great. Thanks for checking! Regards, Lukas