From d6fa7f95bbcaa080810656c79e8879357b312280 Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Mon, 10 Feb 2020 07:42:03 -0800 Subject: doc: sifive: fu540: Update QEMU instruction when using U-Boot as the payload Document that when U-Boot v2020.01 (or higher) is used as the payload, we need adjust the instructions a little bit when testing OpenSBI with QEMU 'sifive_u' machine. Signed-off-by: Bin Meng Reviewed-by: Atish Patra --- docs/platform/sifive_fu540.md | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'docs') diff --git a/docs/platform/sifive_fu540.md b/docs/platform/sifive_fu540.md index 0a9f21e..94eb81f 100644 --- a/docs/platform/sifive_fu540.md +++ b/docs/platform/sifive_fu540.md @@ -183,3 +183,13 @@ same instructions above, with the exception of not passing FW_PAYLOAD_FDT_PATH. This is because QEMU generates a device tree blob on the fly based on the command line parameters and it's compatible with the one used in the upstream Linux kernel. + +When U-Boot v2020.01 (or higher) is used as the payload, as the SiFive FU540 +DTB for the real hardware is embedded in U-Boot binary itself, due to the same +reason above, we need to switch the U-Boot sifive_fu540_defconfig configuration +from CONFIG_OF_SEPARATE to CONFIG_OF_PRIOR_STAGE so that U-Boot uses the DTB +generated by QEMU, and u-boot.bin should be used as the payload image, like: + +``` +make PLATFORM=sifive/fu540 FW_PAYLOAD_PATH=/u-boot.bin +``` -- cgit v1.2.3