Bibo Mao a840d70ee4 target/loongarch: Add compatible support about VM reboot
With edk2-stable202408 LoongArch UEFI bios, CSR PGD register is set only
if its value is equal to zero for boot cpu, it causes reboot issue. Since
CSR PGD register is changed with linux kernel, UEFI BIOS cannot use it.

Add workaround to clear CSR registers relative with TLB in function
loongarch_cpu_reset_hold(), so that VM can reboot with edk2-stable202408
UEFI bios.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Reviewed-by: Song Gao <gaosong@loongson.cn>
Message-Id: <20240827035807.3326293-1-maobibo@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>
2024-09-12 20:51:18 +08:00
..

- Introduction

  LoongArch is the general processor architecture of Loongson.

  The following versions of the LoongArch core are supported
    core: 3A5000
    https://github.com/loongson/LoongArch-Documentation/releases/download/2021.08.17/LoongArch-Vol1-v1.00-EN.pdf

  We can get the latest loongarch documents at https://github.com/loongson/LoongArch-Documentation/tags.


- System emulation

  You can reference docs/system/loongarch/loongson3.rst to get the information about system emulation of LoongArch.

- Linux-user emulation

  We already support Linux user emulation. We can use LoongArch cross-tools to build LoongArch executables on X86 machines,
  and We can also use qemu-loongarch64 to run LoongArch executables.

  1. Config cross-tools env.

     see System emulation.

  2. Test tests/tcg/multiarch.

     ./configure  --static  --prefix=/usr  --disable-werror --target-list="loongarch64-linux-user" --enable-debug

     cd build

     make && make check-tcg

  3. Run LoongArch system basic command with loongarch-clfs-system.

     - Config clfs env.

       wget https://github.com/loongson/build-tools/releases/download/2022.05.29/loongarch64-clfs-system-5.0.tar.bz2

       tar -vxf loongarch64-clfs-system-5.0.tar.bz2 -C /opt/clfs

       cp /opt/clfs/lib64/ld-linux-loongarch-lp64d.so.1  /lib64

       export LD_LIBRARY_PATH="/opt/clfs/lib64"

     - Run LoongArch system basic command.

       ./qemu-loongarch64  /opt/clfs/usr/bin/bash
       ./qemu-loongarch64  /opt/clfs/usr/bin/ls
       ./qemu-loongarch64  /opt/clfs/usr/bin/pwd

- Note.
  We can get the latest LoongArch documents or LoongArch tools at https://github.com/loongson/