docs: platform: Update descriptions for qemu/sifive_u support

With QEMU v4.2 release that has improved the emulation fidelity
of 'sifive_u' machine, OpenSBI v0.4 / U-Boot v2019.10-rc1 / Linux
kernel v5.3-rc2 images built for the SiFive HiFive Unleashed board
can be used out of the box without any special hack.

Update our documents to mention 'qemu/sifive_u' platform should
only be used with QEMU v4.1 or before, and it will be dropped
sometime in the future release.

Going forward, 'sifive/fu540' platform can be used on both real
hardware and QEMU v4.2+ 'sifive_u' machine.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
This commit is contained in:
Bin Meng 2019-09-23 05:49:15 -07:00 committed by Anup Patel
parent 98ee15ca3a
commit 8853758268
2 changed files with 20 additions and 0 deletions

View file

@ -7,6 +7,14 @@ platform.
To build this platform specific library and firmwares, provide the
*PLATFORM=qemu/sifive_u* parameter to the top level `make` command line.
Note with QEMU v4.2 release, the QEMU *sifive_u* machine has been updated to
closely match the SiFive HiFive Unleashed hardware and can therefore run the
same firmware as what gets loaded onto the board, and OpenSBI's *qemu/sifive_u*
platform should only be used with QEMU v4.1 release or before.
The special *qemu/sifive_u* platform support will be dropped in the future
OpenSBI release.
Platform Options
----------------

View file

@ -4,6 +4,9 @@ The FU540-C000 is the worlds 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.
@ -201,3 +204,12 @@ At U-Boot prompt execute the following boot command to boot Linux.
```
bootm ${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_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.