[U-Boot] [PATCH] qemu-arm: Add persistent environment support

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

Sumit,

# I have a similar patch in my local branch :)

On Mon, Nov 26, 2018 at 04:50:17PM +0530, Sumit Garg wrote:
> 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>
> ---
>  configs/qemu_arm64_defconfig | 7 +++++++
>  configs/qemu_arm_defconfig   | 7 +++++++
>  doc/README.qemu-arm          | 6 ++++++
>  include/configs/qemu-arm.h   | 8 +++++++-
>  4 files changed, 27 insertions(+), 1 deletion(-)
> 
> diff --git a/configs/qemu_arm64_defconfig b/configs/qemu_arm64_defconfig
> index f4502c9..0f13716 100644
> --- a/configs/qemu_arm64_defconfig
> +++ b/configs/qemu_arm64_defconfig
> @@ -29,3 +29,10 @@ CONFIG_USB=y
>  CONFIG_DM_USB=y
>  CONFIG_USB_EHCI_HCD=y
>  CONFIG_USB_EHCI_PCI=y
> +CONFIG_ENV_IS_IN_FLASH=y
> +CONFIG_MTD=y
> +CONFIG_MTD_NOR_FLASH=y
> +CONFIG_FLASH_CFI_DRIVER=y

This one and

> +CONFIG_CFI_FLASH=y

> +CONFIG_SYS_FLASH_USE_BUFFER_WRITE=y
> +CONFIG_SYS_FLASH_CFI=y

those two are not currently Kconfig parameters.
So they should not be put in *_defconfig, but in include/configs/*.
Or it would be better to define them as new Kconfigs?

> diff --git a/configs/qemu_arm_defconfig b/configs/qemu_arm_defconfig
> index acebdc5..b75363e 100644
> --- a/configs/qemu_arm_defconfig
> +++ b/configs/qemu_arm_defconfig
> @@ -29,3 +29,10 @@ CONFIG_USB=y
>  CONFIG_DM_USB=y
>  CONFIG_USB_EHCI_HCD=y
>  CONFIG_USB_EHCI_PCI=y
> +CONFIG_ENV_IS_IN_FLASH=y
> +CONFIG_MTD=y
> +CONFIG_MTD_NOR_FLASH=y
> +CONFIG_FLASH_CFI_DRIVER=y
> +CONFIG_CFI_FLASH=y
> +CONFIG_SYS_FLASH_USE_BUFFER_WRITE=y
> +CONFIG_SYS_FLASH_CFI=y
> 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 @@ The minimal QEMU command line to get U-Boot up and running is:
>  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:
>  
> diff --git a/include/configs/qemu-arm.h b/include/configs/qemu-arm.h
> index fedc466..83a930b 100644
> --- a/include/configs/qemu-arm.h
> +++ b/include/configs/qemu-arm.h
> @@ -21,7 +21,8 @@
>  #define CONFIG_SYS_HZ                       1000
>  
>  /* Environment options */
> -#define CONFIG_ENV_SIZE				SZ_64K
> +#define CONFIG_ENV_ADDR			0x4000000
> +#define CONFIG_ENV_SIZE			SZ_256K

# I'm not sure whether those definitions be enforced for all qemu-arm users.

Do you have any reason to put env region in the second bank?
If not, I suggest that it be left free for other use.

Thanks,
-Takahiro Akashi

>  #define BOOT_TARGET_DEVICES(func) \
>  	func(SCSI, scsi, 0) \
> @@ -42,4 +43,9 @@
>  
>  #define CONFIG_SYS_CBSIZE 512
>  
> +#define CONFIG_SYS_MONITOR_BASE		CONFIG_SYS_TEXT_BASE
> +#define CONFIG_SYS_FLASH_BASE		0x0
> +#define CONFIG_SYS_MAX_FLASH_BANKS	2
> +#define CONFIG_SYS_MAX_FLASH_SECT	256 /* Sector: 256K, Bank: 64M */
> +
>  #endif /* __CONFIG_H */
> -- 
> 2.7.4
>