configs: add defconfig for TS-7680

The TS-7680 is an i.MX286 ARM ARM926EJ-S board with 10/100 Ethernet,
USB port, eMMC and CAN ports.

The TS-7680 uses a 3.14.28 Linux kernel provided by Technologic Systems:
https://github.com/embeddedarm/linux-3.14.28-imx28

U-Boot is not provided as the manufacturer recommends not to update the
built-in bootloader.

For more informations please see:
https://wiki.embeddedarm.com/wiki/TS-7680

Signed-off-by: Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>
[Thomas: use same headers as the kernel being built, update .gitlab-ci.yml.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

.gitlab-ci.yml

@@ -206,6 +206,7 @@ toradex_apalis_imx6_defconfig: *defconfig
 ts4800_defconfig: *defconfig
 ts4900_defconfig: *defconfig
 ts5x00_defconfig: *defconfig
+ts7680_defconfig: *defconfig
 wandboard_defconfig: *defconfig
 warp7_defconfig: *defconfig
 warpboard_defconfig: *defconfig

board/technologic/ts7680/genimage.cfg

@@ -0,0 +1,14 @@
+image sdcard.img {
+	hdimage {
+	}
+
+	partition unused {
+		size =  512B
+	}
+
+	partition rootfs {
+		partition-type = 0x83
+		image = "rootfs.ext4"
+		size = 256M
+	}
+}

board/technologic/ts7680/readme.txt

@@ -0,0 +1,51 @@
+Technologic Systems TS-7680 SBC
+===============================
+
+This document explains how to set up a basic Buildroot system for
+the Technologic Systems TS-7680 Single Board Computer.
+
+The TS-7680 SBC is based on the Freescale i.MX286 ARM ARM926EJ-S
+running at 454MHz. The TS-7680 features are 10/100 Ethernet ports,
+Wi-Fi, microSD card, eMMC, NOR Flash, USB host port, CAN ports,
+relays and ADC/DAC. More details on the board here:
+https://wiki.embeddedarm.com/wiki/TS-7680
+
+The TS-7680 uses a 3.14.28 Linux kernel provided by
+Technologic Systems.
+
+To build the default configuration you only have to run:
+
+  $ make ts7680_defconfig
+  $ make
+
+The output looks like:
+output/images
+├── imx28-ts7680.dtb
+├── rootfs.ext2
+├── rootfs.ext4 -> rootfs.ext2
+├── rootfs.tar
+├── sdcard.img
+└── uImage
+
+The provided genimage configuration generates an image file containing
+two partitions. The first one is unused, but mandatory as the
+TS-7680 built-in bootloader loads the Linux uImage from the /boot
+directory in the second partition. The second partition contains the
+rootfs with the Linux uImage into the /boot directory.
+
+  $ fdisk output/images/sdcard.img
+  output/images/sdcard.img1          1      1       1  512B  0 Empty
+  output/images/sdcard.img2          2 524289  524288  256M 83 Linux
+
+This image can be directly written to an SD card.
+
+    $ sudo dd if=output/images/sdcard.img of=/dev/mmcblk0
+
+To boot with Buildroot, insert this SD card on the board, make sure
+the SD jumper is present and the U-Boot jumper is not.
+
+The bootloader comes pre-flashed on the board on an SPI flash. Since
+updating the bootloader is risky and not trivial, it is not included
+in the Buildroot defconfig. Refer to
+https://wiki.embeddedarm.com/wiki/TS-7680#U-Boot for details on
+which U-Boot config to use and how to flash it.

configs/ts7680_defconfig

@@ -0,0 +1,17 @@
+BR2_arm=y
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_3_14=y
+BR2_ROOTFS_POST_IMAGE_SCRIPT="support/scripts/genimage.sh"
+BR2_ROOTFS_POST_SCRIPT_ARGS="-c board/technologic/ts7680/genimage.cfg"
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_GIT=y
+BR2_LINUX_KERNEL_CUSTOM_REPO_URL="https://github.com/embeddedarm/linux-3.14.28-imx28.git"
+BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION="ff01621df09b97d9fd546d1b49f4013060142892"
+BR2_LINUX_KERNEL_DEFCONFIG="ts76xx"
+BR2_LINUX_KERNEL_UIMAGE=y
+BR2_LINUX_KERNEL_UIMAGE_LOADADDR="0x40008000"
+BR2_LINUX_KERNEL_DTS_SUPPORT=y
+BR2_LINUX_KERNEL_INTREE_DTS_NAME="imx28-ts7680"
+BR2_LINUX_KERNEL_INSTALL_TARGET=y
+BR2_TARGET_ROOTFS_EXT2=y
+BR2_TARGET_ROOTFS_EXT2_4=y
+BR2_PACKAGE_HOST_GENIMAGE=y