configs/hifive_unleashed: use mainline Linux + U-Boot

Update to use the official linux kernel v5.10 instead of an
out-of-tree kernel, and use the official U-Boot v2021.01 as the
bootloader. Provide two configuration files of genimage for different
boot flows:

- Boot from SD card (default)
- Boot from SPI flash

A boot script is generated to automatically boot the distro.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

board/sifive/hifive-unleashed/boot.cmd

@@ -0,0 +1,4 @@
+setenv bootargs earlycon=sbi root=/dev/mmcblk0p3 rootwait
+load mmc 0:3 ${kernel_addr_r} boot/Image
+load mmc 0:3 ${fdt_addr_r} boot/hifive-unleashed-a00.dtb
+booti ${kernel_addr_r} - ${fdt_addr_r}

board/sifive/hifive-unleashed/genimage_sdcard.cfg

@@ -3,15 +3,21 @@ image sdcard.img {
 		gpt = true
 	}
 
-	partition bootloader {
+	partition u-boot-spl {
-		image = "fw_payload.bin"
+		image = "u-boot-spl.bin"
-		offset = 1M
+		offset = 17K
-		size = 32M
+		partition-type-uuid = 5B193300-FC78-40CD-8002-E86C45580B47
+	}
+
+	partition u-boot {
+		image = "u-boot.itb"
+		offset = 1041K
 		partition-type-uuid = 2E54B353-1271-4842-806F-E436D6AF6985
 	}
 
 	partition rootfs {
 		image = "rootfs.ext4"
 		partition-type-uuid = 0FC63DAF-8483-4772-8E79-3D69D8477DE4
+		bootable = true
 	}
 }

board/sifive/hifive-unleashed/genimage_spi-nor.cfg

@@ -0,0 +1,19 @@
+image spi-nor.img {
+	size = 32M
+
+	hdimage {
+		gpt = true
+	}
+
+	partition u-boot-spl {
+		image = "u-boot-spl.bin"
+		offset = 20K
+		partition-type-uuid = 5B193300-FC78-40CD-8002-E86C45580B47
+	}
+
+	partition u-boot {
+		image = "u-boot.itb"
+		offset = 1044K
+		partition-type-uuid = 2E54B353-1271-4842-806F-E436D6AF6985
+	}
+}

board/sifive/hifive-unleashed/linux.config.fragment

@@ -1,16 +1,10 @@
 CONFIG_HZ_100=y
-CONFIG_CMDLINE="earlycon=sbi root=/dev/mmcblk0p2 rootwait"
-CONFIG_DEVTMPFS_MOUNT=y
-CONFIG_SERIAL_SIFIVE=y
-CONFIG_SERIAL_SIFIVE_CONSOLE=y
-CONFIG_SPI=y
-CONFIG_SPI_SIFIVE=y
 CONFIG_GPIOLIB=y
 CONFIG_GPIO_SYSFS=y
 CONFIG_GPIO_SIFIVE=y
-CONFIG_MMC=y
+CONFIG_POWER_RESET_GPIO_RESTART=y
-CONFIG_MMC_SPI=y
+CONFIG_MTD=y
-CONFIG_CLK_U54_PRCI=y
+CONFIG_MTD_BLOCK=y
-CONFIG_CLK_GEMGXL_MGMT=y
+CONFIG_MTD_SPI_NOR=y
 CONFIG_PWM=y
 CONFIG_PWM_SIFIVE=y

board/sifive/hifive-unleashed/post-build.sh

@@ -0,0 +1,2 @@
+#!/bin/sh
+cp $BINARIES_DIR/boot.scr $TARGET_DIR/boot/boot.scr

board/sifive/hifive-unleashed/readme.txt

@@ -28,30 +28,41 @@ Result of the build
 Once the build has finished you will have the following files:
 
     output/images/
+    +-- boot.scr
+    +-- fw_dynamic.bin
+    +-- fw_dynamic.elf
     +-- fw_jump.bin
     +-- fw_jump.elf
-    +-- fw_payload.bin
+    +-- hifive-unleashed-a00.dtb
-    +-- fw_payload.elf
     +-- Image
+    +-- rootfs.cpio
     +-- rootfs.ext2
     +-- rootfs.ext4
     +-- rootfs.tar
     +-- sdcard.img
+    +-- u-boot.bin
+    +-- u-boot.itb
+    +-- u-boot-spl.bin
 
 
 Creating a bootable SD card with genimage
 =========================================
 
-Buildroot builds a SD card image for you. All you need to do is dd the
+By default Buildroot builds a SD card image for you. All you need to do
-image to your SD card, which can be done with the following command:
+is dd the image to your SD card, which can be done with the following
+command on your development host:
 
-  $ sudo dd if=output/images/sdcard.img of=/dev/mmcblk0 bs=4096
+  $ sudo dd if=output/images/sdcard.img of=/dev/sdb bs=4096
+
+The above example command assumes the SD card is accessed via a USB card
+reader and shows up as /dev/sdb on the host. Adjust it accordingly per
+your actual setup.
 
 Booting the SD card on the board
 ================================
 
 Make sure that the all DIP switches are set to the off position for
-default boot mode (MSEL mode = 1111), insert the SD card and power
+default boot mode (MSEL mode = 1011), insert the SD card and power
 up the board.
 
 Connect the USB cable and open minicom (/dev/ttyUSB1, 115200, 8N1).
@@ -60,16 +71,45 @@ See the 'SiFive HiFive Unleashed Getting Started Guide' for
 more details (https://www.sifive.com/documentation).
 
 You will get a warning reported by fdisk when you examine the SD card.
-This is because the genimage.cfg file doesn't specify the SD card size
+This is because the genimage_sdcard.cfg file doesn't specify the SD card
-(as people will naturally have different sized cards), so the
+size (as people will naturally have different sized cards), so the
 secondary GPT header is placed after the rootfs rather than at the end
 of the disk where it is expected to be.
 
 You will see something like this at boot time:
 
-[    2.318722] GPT:Primary header thinks Alt. header is not at the end of the disk.
+[    0.989458] mmc0: host does not support reading read-only switch, assuming write-enable
-[    2.325390] GPT:190496 != 122142719
+[    0.996772] mmc0: new SDHC card on SPI
-[    2.328843] GPT:Alternate GPT header not at the end of the disk.
+[    1.001634] mmcblk0: mmc0:0000 SD8GB 7.28 GiB
-[    2.334824] GPT:190496 != 122142719
+[    1.038079] GPT:Primary header thinks Alt. header is not at the end of the disk.
-[    2.338302] GPT: Use GNU Parted to correct GPT errors.
+[    1.044759] GPT:52389 != 15264767
-[    2.343456]  mmcblk0: p1 p2
+[    1.048051] GPT:Alternate GPT header not at the end of the disk.
+[    1.054015] GPT:52389 != 15264767
+[    1.057323] GPT: Use GNU Parted to correct GPT errors.
+[    1.062479]  mmcblk0: p1 p2 p3
+
+
+Creating a bootable SPI flash with genimage
+===========================================
+
+Adjust Buildroot configuration by:
+
+  $ make menuconfig
+
+Change "System configuration" -> "Extra arguments passed to custom scripts"
+value to "-c board/sifive/hifive-unleashed/genimage_spi-nor.cfg", save the
+configuration and build. This creates a output/images/spi-nor.img that can
+be programmed to the on-board SPI flash.
+
+Boot the board from the SD card prepared above, stop the U-Boot auto boot,
+and type the following commands to program the whole SPI flash:
+
+  => tftp 82000000 output/images/spi-nor.img
+  => sf probe
+  => sf update 82000000 0 2000000
+
+Booting the SPI flash on the board
+==================================
+
+Make sure that the all DIP switches are set to the off position for
+default boot mode (MSEL mode = 0110) to boot from SPI flash.

configs/hifive_unleashed_defconfig

@@ -12,29 +12,44 @@ BR2_RISCV_ABI_LP64D=y
 BR2_SYSTEM_DHCP="eth0"
 BR2_TARGET_GENERIC_GETTY=y
 BR2_TARGET_GENERIC_GETTY_PORT="ttySIF0"
+BR2_ROOTFS_POST_BUILD_SCRIPT="board/sifive/hifive-unleashed/post-build.sh"
 BR2_ROOTFS_POST_IMAGE_SCRIPT="support/scripts/genimage.sh"
-BR2_ROOTFS_POST_SCRIPT_ARGS="-c board/sifive/hifive-unleashed/genimage.cfg"
+BR2_ROOTFS_POST_SCRIPT_ARGS="-c board/sifive/hifive-unleashed/genimage_sdcard.cfg"
 
 # Filesystem
+BR2_TARGET_ROOTFS_CPIO=y
 BR2_TARGET_ROOTFS_EXT2=y
 BR2_TARGET_ROOTFS_EXT2_4=y
 
-# Linux headers same as kernel, a 5.1 series
+# Linux headers same as kernel, a 5.10 series
-BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_5_1=y
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_5_10=y
 
 # Kernel
 BR2_LINUX_KERNEL=y
-BR2_LINUX_KERNEL_CUSTOM_GIT=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_REPO_URL="https://github.com/alistair23/linux.git"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.10"
-BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION="hifive-unleashed-5.1"
 BR2_LINUX_KERNEL_USE_ARCH_DEFAULT_CONFIG=y
 BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES="board/sifive/hifive-unleashed/linux.config.fragment"
 BR2_LINUX_KERNEL_IMAGE=y
+BR2_LINUX_KERNEL_DTS_SUPPORT=y
+BR2_LINUX_KERNEL_INTREE_DTS_NAME="sifive/hifive-unleashed-a00"
+BR2_LINUX_KERNEL_INSTALL_TARGET=y
 
 # Bootloader
 BR2_TARGET_OPENSBI=y
-BR2_TARGET_OPENSBI_PLAT="sifive/fu540"
+BR2_TARGET_OPENSBI_PLAT="generic"
-BR2_TARGET_OPENSBI_LINUX_PAYLOAD=y
+BR2_TARGET_UBOOT=y
+BR2_TARGET_UBOOT_CUSTOM_VERSION=y
+BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2021.01"
+BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y
+BR2_TARGET_UBOOT_BOARD_DEFCONFIG="sifive_fu540"
+BR2_TARGET_UBOOT_NEEDS_DTC=y
+BR2_TARGET_UBOOT_NEEDS_OPENSBI=y
+BR2_TARGET_UBOOT_FORMAT_ITB=y
+BR2_TARGET_UBOOT_SPL=y
 
 # Host tools
 BR2_PACKAGE_HOST_GENIMAGE=y
+BR2_PACKAGE_HOST_UBOOT_TOOLS=y
+BR2_PACKAGE_HOST_UBOOT_TOOLS_BOOT_SCRIPT=y
+BR2_PACKAGE_HOST_UBOOT_TOOLS_BOOT_SCRIPT_SOURCE="board/sifive/hifive-unleashed/boot.cmd"