Hi Lukas, On Wed, Oct 31, 2018 at 11:01 PM Auer, Lukas <lukas.a...@aisec.fraunhofer.de> wrote: > > Hi Bin, > > On Wed, 2018-10-31 at 10:13 +0800, Bin Meng wrote: > > Hi Lukas, > > > > On Tue, Oct 30, 2018 at 8:57 PM Lukas Auer > > <lukas.a...@aisec.fraunhofer.de> wrote: > > > > > > RISC-V has two code models, medium low (medlow) and medium any > > > (medany). > > > Medlow limits addressable memory to a single 2 GiB range between > > > the > > > absolute addresses -2 GiB and +2 GiB. Medany limits addressable > > > memory > > > to any single 2 GiB address range. > > > By default, medlow is selected on 32-bit systems and medany on 64- > > > bit > > > systems. This matches the configuration in Linux. > > > > > > The -mcmodel compiler flag is selected according to the Kconfig > > > configuration. > > > > > > Signed-off-by: Lukas Auer <lukas.a...@aisec.fraunhofer.de> > > > --- > > > > > > Changes in v2: > > > - Change ISA string construction, as suggested by Bin Meng > > > > > > arch/riscv/Kconfig | 19 +++++++++++++++++++ > > > arch/riscv/Makefile | 9 ++++++++- > > > 2 files changed, 27 insertions(+), 1 deletion(-) > > > > > > > I had a further look at this, and I suspect we should stick to medlow > > for U-Boot, even for 64-bit. As U-Boot will be only running within > > the > > low 4GB memory space even for 64-bit. Adding medany seems > > unnecessary. > > > > Regards, > > Bin > > You are right, however I think it's actually because U-Boot is compiled > as a position independent binary. U-Boot can be relocated above what's > addressable with 32-bit if the memory is large enough. This should > cause issues with medlow. > I suspects that's the reason, but I am not entirely sure. What do you > think?
Sorry I missed this email. I just found in your v3 this patch was dropped. I think this is still needed to explicitly pass the code model to the compiler. I believe we only need change to: +choice + prompt "Code Model" + default CMODEL_MEDLOW I can include the modified patch in my upcoming series. Regards, Bin _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
