doc: qemu-riscv: Update documentation for QEMU spike machine

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>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/doc/board/emulation/qemu-riscv.rst b/doc/board/emulation/qemu-riscv.rst
index 3409fff8117ea5d0e18942d70b8e96d5fcc89e55..ae998810c8776be81fc59229940ccd4329cb3ac9 100644 (file)
--- a/doc/board/emulation/qemu-riscv.rst
+++ b/doc/board/emulation/qemu-riscv.rst
@@ -4,19 +4,24 @@
 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
+configuration information to guest software. It implements the latest RISC-V
+privileged architecture.
 
 See :doc:`../../develop/devicetree/dt_qemu` for information on how to see
 the devicetree actually generated by QEMU.
-architecture spec v1.10.
+
+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
 ---------------
@@ -41,13 +46,17 @@ 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'
@@ -58,6 +67,7 @@ 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.
 
@@ -80,8 +90,9 @@ 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.
@@ -99,17 +110,22 @@ 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 \