[PATCH v2 1/2] riscv: Support booting SiFive Unmatched from SPI.

[Sean Anderson]

On 11/23/21 11:27 PM, Thomas Skibo wrote:
> Configure SPI flash devices into SPL.  Add SPI boot option to spl.c.
> Document how to format flash for booting.
> 
> Signed-off-by: Thomas Skibo <thomas-git at skibo.net>
> ---
>   .../dts/hifive-unmatched-a00-u-boot.dtsi      | 11 +++++++
>   board/sifive/unmatched/spl.c                  |  3 ++
>   configs/sifive_unmatched_defconfig            |  6 ++++
>   doc/board/sifive/unmatched.rst                | 29 +++++++++++++++++++
>   4 files changed, 49 insertions(+)
> 
> diff --git a/arch/riscv/dts/hifive-unmatched-a00-u-boot.dtsi b/arch/riscv/dts/hifive-unmatched-a00-u-boot.dtsi
> index c5475aa149..1ee8ab1868 100644
> --- a/arch/riscv/dts/hifive-unmatched-a00-u-boot.dtsi
> +++ b/arch/riscv/dts/hifive-unmatched-a00-u-boot.dtsi
> @@ -16,6 +16,10 @@
>   		u-boot,dm-spl;
>   	};
>   
> +	config {
> +		u-boot,spl-payload-offset = <0x105000>; /* loader2 @1044KB */
> +	};
> +
>   	hfclk {
>   		u-boot,dm-spl;
>   	};
> @@ -30,6 +34,13 @@
>   	clocks = <&rtcclk>;
>   };
>   
> +&qspi0 {
> +	u-boot,dm-spl;
> +	flash at 0 {
> +		u-boot,dm-spl;
> +	};
> +};
> +
>   &spi0 {
>   	mmc at 0 {
>   		u-boot,dm-spl;
> diff --git a/board/sifive/unmatched/spl.c b/board/sifive/unmatched/spl.c
> index d5663274cd..7c0beedc08 100644
> --- a/board/sifive/unmatched/spl.c
> +++ b/board/sifive/unmatched/spl.c
> @@ -22,6 +22,7 @@
>   #define GEM_PHY_RESET	SIFIVE_GENERIC_GPIO_NR(0, 12)
>   
>   #define MODE_SELECT_REG		0x1000
> +#define MODE_SELECT_SPI		0x6
>   #define MODE_SELECT_SD		0xb
>   #define MODE_SELECT_MASK	GENMASK(3, 0)
>   
> @@ -123,6 +124,8 @@ u32 spl_boot_device(void)
>   	u32 boot_device = mode_select & MODE_SELECT_MASK;
>   
>   	switch (boot_device) {
> +	case MODE_SELECT_SPI:
> +		return BOOT_DEVICE_SPI;
>   	case MODE_SELECT_SD:
>   		return BOOT_DEVICE_MMC1;
>   	default:
> diff --git a/configs/sifive_unmatched_defconfig b/configs/sifive_unmatched_defconfig
> index 9cc18b029c..d400ed0b23 100644
> --- a/configs/sifive_unmatched_defconfig
> +++ b/configs/sifive_unmatched_defconfig
> @@ -8,6 +8,7 @@ CONFIG_SPL_DM_SPI=y
>   CONFIG_DEFAULT_DEVICE_TREE="hifive-unmatched-a00"
>   CONFIG_SPL_MMC=y
>   CONFIG_SPL=y
> +CONFIG_SPL_SPI_FLASH_SUPPORT=y
>   CONFIG_SPL_SPI=y
>   CONFIG_AHCI=y
>   CONFIG_TARGET_SIFIVE_UNMATCHED=y
> @@ -23,17 +24,22 @@ CONFIG_DISPLAY_BOARDINFO=y
>   CONFIG_DISPLAY_BOARDINFO_LATE=y
>   CONFIG_ID_EEPROM=y
>   CONFIG_SPL_SEPARATE_BSS=y
> +CONFIG_SPL_DM_SPI_FLASH=y
>   CONFIG_SPL_DM_RESET=y
> +CONFIG_SPL_SPI_LOAD=y
>   CONFIG_CMD_EEPROM=y
>   CONFIG_CMD_MEMINFO=y
>   CONFIG_CMD_PWM=y
>   CONFIG_CMD_GPT_RENAME=y
>   CONFIG_CMD_PCI=y
>   CONFIG_CMD_USB=y
> +CONFIG_USE_ENV_SPI_BUS=y
> +CONFIG_ENV_SPI_BUS=1
>   CONFIG_SYS_RELOC_GD_ENV_ADDR=y
>   CONFIG_SCSI_AHCI=y
>   CONFIG_AHCI_PCI=y
>   CONFIG_SPL_CLK=y
> +CONFIG_SPI_FLASH_ISSI=y
>   CONFIG_SYS_I2C_EEPROM_ADDR=0x54
>   CONFIG_E1000=y
>   CONFIG_NVME=y
> diff --git a/doc/board/sifive/unmatched.rst b/doc/board/sifive/unmatched.rst
> index 6b024f07f6..387785d76b 100644
> --- a/doc/board/sifive/unmatched.rst
> +++ b/doc/board/sifive/unmatched.rst
> @@ -534,3 +534,32 @@ Sample boot log from HiFive Unmatched board
>   	OpenEmbedded nodistro.0 unmatched ttySIF0
>   
>   	unmatched login:
> +
> +
> +Booting from SPI
> +----------------
> +
> +Use Building steps from "Booting from uSD using U-Boot SPL" section.
> +
> +Partition the SPI in Linux via mtdblock.
> +
> +.. code-block:: none
> +
> +	sgdisk --clear -a 1 \
> +	    --new=1:40:2087     --change-name=1:spl   --typecode=1:5B193300-FC78-40CD-8002-E86C45580B47 \
> +	    --new=2:2088:10279  --change-name=2:uboot --typecode=2:2E54B353-1271-4842-806F-E436D6AF6985 \
> +	    --new=3:10280:10535 --change-name=3:env   --typecode=3:0FC63DAF-8483-4772-8E79-3D69D8477DE4 \

nit: Please use hexcodes as printed with sgdisk -L. And also document
what the type is. Documentation is for us humans after all :)

--Sean

> +	    /dev/mtdblock0
> +
> +Write U-boot SPL and U-boot to their partitions.
> +
> +.. code-block:: none
> +
> +	dd if=u-boot-spl.bin of=/dev/mtdblock0 bs=4096 seek=5 conv=sync
> +	dd if=u-boot.itb  of=/dev/mtdblock0 bs=4096 seek=261 conv=sync
> +
> +Power off the board.
> +
> +Change DIP switches MSEL[3:0] to 0110.
> +
> +Power up the board.
>