Add submodule dependency filesHEADmaster

Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec

1 files changed, 195 insertions, 0 deletions

diff --git a/roms/opensbi/docs/platform/sifive_fu540.md b/roms/opensbi/docs/platform/sifive_fu540.md
new file mode 100644
index 000000000..b4d3c6051
--- /dev/null
+++ b/roms/opensbi/docs/platform/sifive_fu540.md
@@ -0,0 +1,195 @@
+SiFive FU540 SoC Platform
+=========================
+The FU540-C000 is the world’s first 4+1 64-bit RISC-V SoC from SiFive.
+The HiFive Unleashed development platform is based on FU540-C000 and capable
+of running Linux.
+
+With QEMU v4.2 or above release, the 'sifive_u' machine can be used to test
+OpenSBI image built for the real hardware as well.
+
+To build platform specific library and firmwares, provide the
+*PLATFORM=sifive/fu540* parameter to the top level `make` command.
+
+Platform Options
+----------------
+
+The *SiFive FU540 SoC* platform does not have any platform-specific
+options.
+
+Building SiFive Fu540 Platform
+------------------------------
+
+In order to boot SMP Linux in U-Boot, Linux v5.1 (or higher) and latest
+U-Boot v2020.01 (or higher) should be used.
+
+**Linux Kernel Payload**
+
+The HiFive Unleashed device tree(DT) is merged in Linux v5.2 release. This
+DT (device tree) is not backward compatible with the DT passed from FSBL.
+
+To use Linux v5.2 (or higher), the pre-built DTB (DT binary) from Linux v5.2
+(or higher) should be used to build SiFive FU540 OpenSBI binaries by using
+the compile time option *FW_FDT_PATH*.
+
+```
+make PLATFORM=sifive/fu540 FW_PAYLOAD_PATH=<linux_build_directory>/arch/riscv/boot/Image
+or
+(For Linux v5.2 or higher)
+make PLATFORM=sifive/fu540 FW_PAYLOAD_PATH=<linux_build_directory>/arch/riscv/boot/Image FW_FDT_PATH=<hifive-unleashed-a00.dtb path from Linux kernel>
+```
+
+**U-Boot Payload**
+
+The command-line example here assumes that U-Boot was compiled using the
+sifive_fu540_defconfig configuration and with U-Boot v2020.01, and up to
+v2020.07-rc3.
+
+```
+make PLATFORM=sifive/fu540 FW_PAYLOAD_PATH=<u-boot_build_dir>/u-boot-dtb.bin
+```
+For U-Boot v2020.07-rc4 or later releases, SPL support was added in U-Boot.
+Please refer to the detailed U-Boot booting guide available at [U-Boot].
+
+Flashing the OpenSBI firmware binary to storage media:
+------------------------------------------------------
+The first stage boot loader ([FSBL]) expects the storage media to have a GPT
+partition table. It tries to look for a partition with following GUID to load
+the next stage boot loader (OpenSBI in this case).
+
+```
+2E54B353-1271-4842-806F-E436D6AF6985
+```
+
+That's why the generated firmware binary in above steps should be copied to
+the partition of the sdcard with above GUID.
+
+```
+dd if=build/platform/sifive/fu540/firmware/fw_payload.bin of=/dev/disk2s1 bs=1024
+```
+
+In my case, it is the first partition is **disk2s1** that has been formatted
+with the above specified GUID.
+
+In case of a brand new sdcard, it should be formatted with below partition
+tables as described here.
+
+```
+sgdisk --clear                                                               \
+       --new=1:2048:67583  --change-name=1:bootloader --typecode=1:2E54B353-1271-4842-806F-E436D6AF6985   \
+       --new=2:264192:     --change-name=2:root       --typecode=2:0FC63DAF-8483-4772-8E79-3D69D8477DE4 \
+       ${DISK}
+```
+
+Booting SiFive Fu540 Platform
+-----------------------------
+
+**Linux Kernel Payload**
+
+As Linux kernel image is embedded in the OpenSBI firmware binary, HiFive
+Unleashed will directly boot into Linux directly after powered on.
+
+**U-Boot Payload**
+
+As U-Boot image is used as payload, HiFive Unleashed will boot into a U-Boot
+prompt. U-Boot tftp boot method can be used to load kernel image in U-Boot
+prompt. Here are the steps do a tftpboot.
+
+1. Set the ip address of the board.
+```
+setenv ipaddr <ipaddr of the board>
+```
+2. Set the tftpboot server IP.
+```
+setenv serverip <ipaddr of the tftp server>
+```
+3. Set the network gateway address.
+```
+setenv gatewayip <ipaddress of the network gateway>
+```
+4. Load the Linux kernel image from the tftp server.
+```
+tftpboot ${kernel_addr_r} <Image path in tftpboot directory>
+```
+5. Load the ramdisk image from the tftp server. This is only required if
+ramdisk is loaded from tftp server. This step is optional, if rootfs is
+already part of the kernel or loaded from an external storage by kernel.
+```
+tftpboot ${ramdisk_addr_r} <ramdisk path in tftpboot directory>
+```
+6. Load the pre-compiled device tree via tftpboot.
+```
+tftpboot ${fdt_addr_r} <hifive-unleashed-a00.dtb path in tftpboot directory>
+```
+7. Set the boot command-line arguments.
+```
+setenv bootargs "root=<root partition> rw console=ttySIF0 earlycon=sbi"
+```
+(Note: root partition should point to
+** /dev/ram ** - If a ramdisk is used
+** root=/dev/mmcblk0pX ** - If a rootfs is already on some other partition
+of sdcard)
+8. Now boot into Linux.
+```
+booti ${kernel_addr_r} ${ramdisk_addr_r} ${fdt_addr_r}
+or
+(If ramdisk is not loaded from network)
+booti ${kernel_addr_r} - ${fdt_addr_r}
+```
+
+**U-Boot & Linux Kernel as a single payload**
+
+At U-Boot prompt execute the following boot command to boot Linux.
+
+```
+booti ${kernel_addr_r} - ${fdt_addr_r}
+```
+
+QEMU Specific Instructions
+--------------------------
+If you want to test OpenSBI with QEMU 'sifive_u' machine, please follow the
+same instructions above, with the exception of not passing FW_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_build_dir>/u-boot.bin
+```
+
+U-Boot v2020.07 release added SPL support to SiFive HiFive Unleashed board,
+hence a build error will be seen after you switch to **CONFIG_OF_PRIOR_STAGE**.
+
+```
+./tools/mkimage: Can't open arch/riscv/dts/hifive-unleashed-a00.dtb: No such file or directory
+./tools/mkimage: failed to build FIT
+Makefile:1402: recipe for target 'u-boot.img' failed
+make: *** [u-boot.img] Error 1
+```
+
+The above errors can be safely ignored as we don't run U-Boot SPL under QEMU.
+
+Run:
+```
+qemu-system-riscv64 -M sifive_u -m 256M -nographic \
+	-bios build/platform/sifive/fu540/firmware/fw_payload.bin
+```
+or
+```
+qemu-system-riscv64 -M sifive_u -m 256M -nographic \
+	-bios build/platform/sifive/fu540/firmware/fw_jump.bin \
+	-kernel <uboot_build_dir>/u-boot.bin
+```
+
+While the real hardware operates at the 64-bit mode, it's possible for QEMU to
+test the 32-bit OpenSBI firmware. This can be helpful for testing 32-bit SiFive
+specific drivers.
+
+[U-Boot]: https://gitlab.denx.de/u-boot/u-boot/blob/master/doc/board/sifive/fu540.rst
+[FSBL]: https://github.com/sifive/freedom-u540-c000-bootloader