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Re: [PATCH 0/3] Add OpenSBI dynamic firmware support
From: |
Atish Patra |
Subject: |
Re: [PATCH 0/3] Add OpenSBI dynamic firmware support |
Date: |
Thu, 18 Jun 2020 11:19:09 -0700 |
On Thu, Jun 18, 2020 at 1:56 AM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> On Wed, Jun 17, 2020 at 3:29 AM Atish Patra <atish.patra@wdc.com> wrote:
> >
> > This series adds support OpenSBI dynamic firmware support to Qemu.
> > Qemu loader passes the information about the DT and next stage (i.e. kernel
> > or U-boot) via "a2" register. It allows the user to build bigger OS images
> > without worrying about overwriting DT. It also unifies the reset vector code
>
> I am not sure in what situation overwriting DT could happen. Could you
> please elaborate?
>
Currently, the DT is loaded 0x82200000 (34MB offset) for fw_jump.
Thus, a bigger kernel image
would overwrite the DT. In fact, it was reported by FreeBSD folks.
https://github.com/riscv/opensbi/issues/169
There are temporary solutions that can put DT a little bit further or
put it within 2MB offset. But that's
just delaying the inevitable.
> > in rom and dt placement. Now, the DT is copied directly in DRAM instead of
> > ROM.
> >
> > The changes have been verified on following qemu machines.
> >
> > 64bit:
> > - spike, sifive_u, virt
> > 32bit:
> > - virt
>
> Any test instructions?
>
you just need to provide fw_dynamic instead of fw_jump in bios argument.
For example: Here is my qemu commandline for testing
qemu-system-riscv64 -M virt -smp 4 -m 2g -display none -serial
mon:stdio -bios
~/workspace/opensbi/build/platform/generic/firmware/fw_dynamic.bin \
-kernel /home/atish/workspace/linux/arch/riscv/boot/Image -initrd
/home/atish/workspace/rootfs_images/riscv64_busybox_rootfs.img -object
rng-random,filename=/dev/urandom,id=rng0 \
-device virtio-rng-device,rng=rng0 -device
virtio-net-device,netdev=usernet -netdev
user,id=usernet,hostfwd=tcp::10000-:22 -d in_asm -D log -append 'rw
console=ttyS0 earlycon'
> >
> > I have also verified fw_jump on all the above platforms to ensure that this
> > series doesn't break the existing setup.
> >
>
> Regards,
> Bin
>
--
Regards,
Atish
- [PATCH 1/3] riscv: Unify Qemu's reset vector code path, (continued)
- [PATCH 1/3] riscv: Unify Qemu's reset vector code path, Atish Patra, 2020/06/16
- [PATCH 2/3] RISC-V: Copy the fdt in dram instead of ROM, Atish Patra, 2020/06/16
- [PATCH 3/3] riscv: Add opensbi firmware dynamic support, Atish Patra, 2020/06/16
- Re: [PATCH 0/3] Add OpenSBI dynamic firmware support, no-reply, 2020/06/16
- Re: [PATCH 0/3] Add OpenSBI dynamic firmware support, Bin Meng, 2020/06/18
- Re: [PATCH 0/3] Add OpenSBI dynamic firmware support,
Atish Patra <=