[PATCH v2 4/4] doc: qemu-riscv: Update documentation for QEMU spike machine

Anup Patel
2022-01-27T06:12:26Z

We can now use same U-Boot images on both QEMU virt machine and QEMU
spike machine so let's update the QEMU RISC-V documentation.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
doc/board/emulation/qemu-riscv.rst | 48 ++++++++++++++++++++----------
1 file changed, 32 insertions(+), 16 deletions(-)

diff --git a/doc/board/emulation/qemu-riscv.rst b/doc/board/emulation/qemu-riscv.rst
index 4b8e104a21..0a4b121687 100644
--- a/doc/board/emulation/qemu-riscv.rst
+++ b/doc/board/emulation/qemu-riscv.rst
@@ -4,16 +4,21 @@
QEMU RISC-V
===========

-QEMU for RISC-V supports a special 'virt' machine designed for emulation and
-virtualization purposes. This document describes how to run U-Boot under it.
-Both 32-bit and 64-bit targets are supported, running in either machine or
-supervisor mode.
+QEMU for RISC-V supports a special 'virt' machine and 'spike' machine designed
+for emulation and virtualization purposes. This document describes how to run
+U-Boot under it. Both 32-bit and 64-bit targets are supported, running in
+either machine or supervisor mode.

The QEMU virt machine models a generic RISC-V virtual machine with support for
the VirtIO standard networking and block storage devices. It has CLINT, PLIC,
16550A UART devices in addition to VirtIO and it also uses device-tree to pass
-configuration information to guest software. It implements RISC-V privileged
-architecture spec v1.10.
+configuration information to guest software. It implements the latest RISC-V
+privileged architecture.
+
+The QEMU spike machine models a minimalistic RISC-V virtual machine with
+only CLINT and HTIF devices. It also uses device-tree to pass configuration
+information to guest software and implements the latest RISC-V privileged
+architecture.

Building U-Boot
---------------
@@ -38,13 +43,17 @@ Running U-Boot
--------------
The minimal QEMU command line to get U-Boot up and running is:

-- For 32-bit RISC-V::
+- For 32-bit RISC-V virt machine::

- qemu-system-riscv32 -nographic -machine virt -bios u-boot
+ qemu-system-riscv32 -nographic -machine virt -bios u-boot.bin

-- For 64-bit RISC-V::
+- For 64-bit RISC-V virt machine::
+
+ qemu-system-riscv64 -nographic -machine virt -bios u-boot.bin
+
+- For 64-bit RISC-V spike machine::

- qemu-system-riscv64 -nographic -machine virt -bios u-boot
+ qemu-system-riscv64 -nographic -machine spike -bios u-boot.bin

The commands above create targets with 128MiB memory by default.
A freely configurable amount of RAM can be created via the '-m'
@@ -55,6 +64,7 @@ the new setting.
For instructions on how to run U-Boot in supervisor mode on QEMU
with OpenSBI, see the documentation available with OpenSBI:
https://github.com/riscv/opensbi/blob/master/docs/platform/qemu_virt.md
+https://github.com/riscv/opensbi/blob/master/docs/platform/spike.md

These have been tested in QEMU 5.0.0.

@@ -77,8 +87,9 @@ supported by U-Boot. Clone the OpenSBI repository and run the following command.

See the OpenSBI documentation for full details:
https://github.com/riscv/opensbi/blob/master/docs/platform/qemu_virt.md
+https://github.com/riscv/opensbi/blob/master/docs/platform/spike.md

-To make the FW_DYNAMIC binary (build/platform/qemu/virt/firmware/fw_dynamic.bin)
+To make the FW_DYNAMIC binary (build/platform/generic/firmware/fw_dynamic.bin)
available to U-Boot, either copy it into the U-Boot root directory or specify
its location with the OPENSBI environment variable. Afterwards, compile U-Boot
with the following commands.
@@ -96,17 +107,22 @@ with the following commands.
The minimal QEMU commands to run U-Boot SPL in both 32-bit and 64-bit
configurations are:

-- For 32-bit RISC-V::
+- For 32-bit RISC-V virt machine::

- qemu-system-riscv32 -nographic -machine virt -bios spl/u-boot-spl \
+ qemu-system-riscv32 -nographic -machine virt -bios spl/u-boot-spl.bin \
-device loader,file=u-boot.itb,addr=0x80200000

-- For 64-bit RISC-V::
+- For 64-bit RISC-V virt machine::
+
+ qemu-system-riscv64 -nographic -machine virt -bios spl/u-boot-spl.bin \
+ -device loader,file=u-boot.itb,addr=0x80200000
+
+- For 64-bit RISC-V spike machine::

- qemu-system-riscv64 -nographic -machine virt -bios spl/u-boot-spl \
+ qemu-system-riscv64 -nographic -machine spike -bios spl/u-boot-spl.bin \
-device loader,file=u-boot.itb,addr=0x80200000

-An attached disk can be emulated by adding::
+An attached disk can be emulated in RISC-V virt machine by adding::

-device ich9-ahci,id=ahci \
-drive if=none,file=riscv64.img,format=raw,id=mydisk \
--
2.25.1