qemu-arm: Add persistent environment support
Currently on qemu-arm platforms environment is kept in RAM. Instead
use pflash device 1 to provide persistent environment support across
device reset.
Also (optionally) provide support for persistent environment across
qemu machine OFF/ON using following instructions:
- Create envstore.img using qemu-img:
qemu-img create -f raw envstore.img 64M
- Add a pflash drive parameter to the command line:
-drive if=pflash,format=raw,index=1,file=envstore.img
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
diff --git a/doc/README.qemu-arm b/doc/README.qemu-arm
index 2601656..e67bc13 100644
--- a/doc/README.qemu-arm
+++ b/doc/README.qemu-arm
@@ -47,6 +47,12 @@
Note that for some odd reason qemu-system-aarch64 needs to be explicitly
told to use a 64-bit CPU or it will boot in 32-bit mode.
+Additional persistent U-boot environment support can be added as follows:
+- Create envstore.img using qemu-img:
+ qemu-img create -f raw envstore.img 64M
+- Add a pflash drive parameter to the command line:
+ -drive if=pflash,format=raw,index=1,file=envstore.img
+
Additional peripherals that have been tested to work in both U-Boot and Linux
can be enabled with the following command line parameters: