Add a reST document to describe how to build and run U-Boot for the QEMU ppce500 machine.
Signed-off-by: Bin Meng bmeng.cn@gmail.com Reviewed-by: Simon Glass sjg@chromium.org Reviewed-by: Priyanka Jain priyanka.jain@nxp.com
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Changes in v3: - rebase on top of u-boot/master
Changes in v2: - add descriptions for VirtIO BLK, RTC and power off
doc/board/emulation/index.rst | 1 + doc/board/emulation/qemu-ppce500.rst | 88 ++++++++++++++++++++++++++++++++++++ 2 files changed, 89 insertions(+) create mode 100644 doc/board/emulation/qemu-ppce500.rst
diff --git a/doc/board/emulation/index.rst b/doc/board/emulation/index.rst index a09ead1..be66b6b 100644 --- a/doc/board/emulation/index.rst +++ b/doc/board/emulation/index.rst @@ -8,6 +8,7 @@ Emulation
qemu-arm qemu-mips + qemu-ppce500 qemu-riscv qemu-x86 qemu_capsule_update diff --git a/doc/board/emulation/qemu-ppce500.rst b/doc/board/emulation/qemu-ppce500.rst new file mode 100644 index 0000000..0a5c86c --- /dev/null +++ b/doc/board/emulation/qemu-ppce500.rst @@ -0,0 +1,88 @@ +.. SPDX-License-Identifier: GPL-2.0+ +.. Copyright (C) 2021, Bin Meng bmeng.cn@gmail.com + +QEMU PPC E500 +============= + +QEMU for PPC supports a special 'ppce500' machine designed for emulation and +virtualization purposes. This document describes how to run U-Boot under it. + +The QEMU ppce500 machine models a generic PowerPC E500 virtual machine with +support for the VirtIO standard networking device connected to the built-in +PCI host controller. Some common devices in the CCSBAR space are modeled, +including MPIC, 16550A UART devices, GPIO, I2C and PCI host controller with +MSI delivery to MPIC. It uses device-tree to pass configuration information +to guest software. + +Building U-Boot +--------------- +Set the CROSS_COMPILE environment variable as usual, and run:: + + $ make qemu-ppce500_defconfig + $ make + +Running U-Boot +-------------- +The minimal QEMU command line to get U-Boot up and running is:: + + $ qemu-system-ppc -nographic -machine ppce500 -bios u-boot + +You can also run U-Boot using 'qemu-system-ppc64':: + + $ qemu-system-ppc64 -nographic -machine ppce500 -bios u-boot + +The commands above create a target with 128 MiB memory by default. A freely +configurable amount of RAM can be created via the '-m' parameter. For example, +'-m 2G' creates 2 GiB memory for the target, and the memory node in the +embedded DTB created by QEMU reflects the new setting. + +Both qemu-system-ppc and qemu-system-ppc64 provide emulation for the following +32-bit PowerPC CPUs: + +* e500v2 +* e500mc + +Additionally qemu-system-ppc64 provides support for the following 64-bit CPUs: + +* e5500 +* e6500 + +The CPU type can be specified via the '-cpu' command line. If not specified, +it creates a machine with e500v2 core. The following example shows an e6500 +based machine creation:: + + $ qemu-system-ppc64 -nographic -machine ppce500 -cpu e6500 -bios u-boot + +When U-Boot boots, you will notice the following:: + + CPU: Unknown, Version: 0.0, (0x00000000) + Core: e6500, Version: 2.0, (0x80400020) + +This is because we only specified a core name to QEMU and it does not have a +meaningful SVR value which represents an actual SoC that integrates such core. +You can specify a real world SoC device that QEMU has built-in support but all +these SoCs are e500v2 based MPC85xx series, hence you cannot test anything +built for P4080 (e500mc), P5020 (e5500) and T2080 (e6500). + +By default a VirtIO standard PCI networking device is connected as an ethernet +interface at PCI address 0.1.0, but we can switch that to an e1000 NIC by:: + + $ qemu-system-ppc -nographic -machine ppce500 -bios u-boot \ + -nic tap,ifname=tap0,script=no,downscript=no,model=e1000 + +VirtIO BLK driver is also enabled to support booting from a disk image where +a kernel image is stored. Append the following to QEMU:: + + -drive file=disk.img,format=raw,id=disk0 -device virtio-blk-pci,drive=disk0 + +Pericom pt7c4338 RTC is supported so we can use the 'date' command:: + + => date + Date: 2021-02-18 (Thursday) Time: 15:33:20 + +Additionally, 'poweroff' command is supported to shut down the QEMU session:: + + => poweroff + poweroff ... + +These have been tested in QEMU 5.2.0.