board/minnowboard-max: Rework to generate SD card image

Let's rework the board and config files to use genimage
to generate the SD card image directly.

[Peter: add host-mtools for genimage vfat handling]
Signed-off-by: Ezequiel García <ezequiel@vanguardiasur.com.ar>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

board/minnowboard-max/genimage.cfg

@@ -0,0 +1,34 @@
+# Create an image of the efi partition
+image efi-part.vfat {
+	vfat {
+		file startup.nsh {
+			image = "efi-part/startup.nsh"
+		}
+		file EFI {
+			image = "efi-part/EFI"
+		}
+		file bzImage {
+			image = "bzImage"
+		}
+	}
+	size=10M
+}
+
+# Create the sdcard image, pulling in
+#  * the image created by buildroot
+#  * the efi-partition created above
+image sdcard.img {
+	hdimage {
+	}
+
+	partition boot {
+		partition-type = 0xEF
+		image = "efi-part.vfat"
+	}
+
+	partition rootfs {
+		partition-type = 0x83
+		image = "rootfs.ext4"
+		size = 512M
+	}
+}

board/minnowboard-max/post-image.sh

@@ -0,0 +1,13 @@
+#!/bin/sh -e
+
+GENIMAGE_CFG="board/minnowboard-max/genimage.cfg"
+GENIMAGE_TMP="${BUILD_DIR}/genimage.tmp"
+
+rm -rf "${GENIMAGE_TMP}"
+
+genimage \
+    --rootpath "${TARGET_DIR}" \
+    --tmppath "${GENIMAGE_TMP}" \
+    --inputpath "${BINARIES_DIR}" \
+    --outputpath "${BINARIES_DIR}" \
+    --config "${GENIMAGE_CFG}"

board/minnowboard-max/readme.txt

@@ -1,40 +1,25 @@
-Prepare the SD card for the Minnow Board MAX
+How to get started with the Minnow Board MAX
 ============================================
 
- 1. Partition the SD card with a GPT partition table
+1. Build
 
-    sudo cgdisk /dev/mmcblk0
+  Apply the defconfig:
 
-    Create two partitions:
+  $ make minnowboard_max_defconfig
 
-     a) First partition of a few dozens of megabytes, which will be
-        used to store the bootloader and the kernel image. Type must
-        be EF00 (EFI partition).
+  Add any additional packages required and build:
 
-     b) Second partition of any size, which will be used to store the
-        root filesystem. Type must be 8300 (Linux filesystem)
+  $ make
 
- 2. Prepare the boot partition
+2. Write the SD card
 
-    We will format it, mount it, copy the EFI data generated by
-    Buildroot, and the kernel image.
+  The build process will create a SD card image in output/images.
+  Write the image to an mSD card, insert into the Minnowboard MAX
+  and power the board on.
 
-    sudo mkfs.vfat -F 32 -n boot /dev/mmcblk0p1
-    sudo mount /dev/mmcblk0p1 /mnt
-    sudo cp -a output/images/efi-part/* /mnt/
-    sudo cp output/images/bzImage /mnt/
-    sudo umount /mnt
+  $ dd if=output/images/sdcard.img of=/dev/mmcblk0; sync
 
- 3. Prepare the root partition
-
-    We will format it, mount it, and extract the root filesystem.
-
-    sudo mkfs.ext4 -L root /dev/mmcblk0p2
-    sudo mount /dev/mmcblk0p2 /mnt
-    sudo tar -C /mnt -xf output/images/rootfs.tar
-    sudo umount /mnt
-
- 4. Enjoy
+3. Enjoy
 
 Additional information about this board can be found at
 http://www.minnowboard.org/ or http://wiki.minnowboard.org/MinnowBoard_MAX

configs/minnowboard_max_defconfig

@@ -5,9 +5,13 @@ BR2_x86_atom=y
 # Misc
 BR2_TARGET_GENERIC_GETTY_PORT="ttyS0"
 BR2_ROOTFS_POST_BUILD_SCRIPT="board/minnowboard-max/post-build.sh"
+BR2_ROOTFS_POST_IMAGE_SCRIPT="board/minnowboard-max/post-image.sh"
 
 # Linux headers same as kernel, a 4.4 series
 BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_4=y
+BR2_PACKAGE_HOST_DOSFSTOOLS=y
+BR2_PACKAGE_HOST_GENIMAGE=y
+BR2_PACKAGE_HOST_MTOOLS=y
 
 # Needed for ethernet
 BR2_PACKAGE_LINUX_FIRMWARE=y
@@ -23,3 +27,8 @@ BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/minnowboard-max/linux.config"
 # Bootloader
 BR2_TARGET_GRUB2=y
 BR2_TARGET_GRUB2_X86_64_EFI=y
+
+# Filesystem image
+BR2_TARGET_ROOTFS_EXT2=y
+BR2_TARGET_ROOTFS_EXT2_4=y
+# BR2_TARGET_ROOTFS_TAR is not set