Hi Atish, On Fri, Dec 18, 2020 at 3:27 PM Atish Patra <atish.pa...@wdc.com> wrote: > > On Fri, 2020-12-18 at 15:21 +0800, Bin Meng wrote: > > Hi Atish, > > > > On Fri, Dec 18, 2020 at 5:48 AM Atish Patra <atish.pa...@wdc.com> > > wrote: > > > > > > Currently, we place the DTB at 2MB from 4GB or end of DRAM which > > > ever is > > > lesser. However, Linux kernel can address only 1GB of memory for > > > RV32. > > > Thus, it can not map anything beyond 3GB (assuming 2GB is the > > > starting address). > > > As a result, it can not process DT and panic if opensbi dynamic > > > firmware > > > is used. > > > > > > Fix this by placing the DTB at 2MB from 3GB or end of DRAM > > > whichever is lower. > > > > > > Signed-off-by: Atish Patra <atish.pa...@wdc.com> > > > --- > > > hw/riscv/boot.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > > With this patch, 32-bit sifive_u still does not boot kernel with the > > following patch applied on 5.10: > > https://patchwork.kernel.org/project/linux-riscv/patch/20201217074855.1948743-1-atish.pa...@wdc.com/ > > > > Command I used: > > $ qemu-system-riscv32 -nographic -M sifive_u -m 1G -smp 5 -kernel > > arch/riscv/boot/Image > > > > 32-bit virt cannot boot the same kernel image with memory set to 2G > > either: > > $ qemu-system-riscv32 -nographic -M virt -m 2G -smp 4 -kernel > > arch/riscv/boot/Image > > > > Hi Bin, > As mentioned in the email on the linux mailing list, this patch only > solves 2GB problem. sifive_u problem is solved by Alistair's patch[1]. > > He is planning to send the PR soon. The issue with sifive_u boot was it > was failing the 32 bit test earlier resulting a 2MB aligned address > instead of 4MB.
Ah, I see. However my testing shows that virt with 2G still does not boot with this patch. > > [1] https://www.mail-archive.com/qemu-devel@nongnu.org/msg767886.html > Regards, Bin