BeagleBoneBlack
U-boot
Let's build the uboot to generate MLO and u-boot.img files.
$ git clone git://git.denx.de/u-boot.git
Build!
$ make am335x_evm_defconfig
$ make CROSS_COMPILE=arm-linux-gnueabihf-
... build process ...
SHIPPED dts/dt.dtb
MKIMAGE u-boot.img
CAT u-boot-dtb.bin
COPY u-boot.dtb
MKIMAGE u-boot-dtb.img
COPY u-boot.bin
...
LD spl/u-boot-spl
OBJCOPY spl/u-boot-spl-nodtb.bin
COPY spl/u-boot-spl.bin
MKIMAGE MLO
The MLO and u-boot.img will be written into the SD card.
SD card partition
| start | size (KB) | description |
|---|---|---|
| 0 | 128 | MLO |
| 128 | 384 | Uboot |
| 2048 | end of SD | Alpine Linux |
Format the SD card. In my system, sdb is the mount location of SD card.
Please note that it depends on the system.
$ sudo dd if=/dev/zero of=/dev/sdb bs=1M count=10
Writing MLO
$ sudo dd if=MLO of=/dev/sdb count=1 seek=1 bs=128k
0+1 records in
0+1 records out
77876 bytes (78 kB) copied, 0.0147161 s, 5.3 MB/s
Writing u-boot.img
$ sudo dd if=u-boot.img of=/dev/sdb count=2 seek=1 bs=384k
0+1 records in
0+1 records out
365092 bytes (365 kB) copied, 0.0127763 s, 28.6 MB/s
Creating a partition for Alpine Linux
$ sudo fdisk /dev/sdb
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
Partition number (1-4, default 1): 1
First sector (2048-31275007, default 2048): 2048
Last sector, +sectors or +size{K,M,G} (2048-31275007, default 31275007):
Using default value 31275007
Command (m for help): w
The partition table has been altered!
$ sudo mkfs.fat /dev/sdb1
Let's check whether created partition is ok or not
$ sudo fdisk /dev/sdb
Command (m for help): p
Disk /dev/sdb: 16.0 GB, 16012804096 bytes
64 heads, 32 sectors/track, 15271 cylinders, total 31275008 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xd2858c87
Device Boot Start End Blocks Id System
/dev/sdb1 2048 31275007 15636480 83 Linux
It should be a bootable partition. To set the bootable flag, select 'a' in the menu
Command (m for help): a
Partition number (1-4): 1
Double check!
Command (m for help): p
Disk /dev/sdb: 16.0 GB, 16012804096 bytes
64 heads, 32 sectors/track, 15271 cylinders, total 31275008 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xd2858c87
Device Boot Start End Blocks Id System
/dev/sdb1 * 2048 31275007 15636480 83 Linux
OK, now the 1st partition is bootable. Then, let's make the EXT4 file system for rootfs.
$ sudo mkfs.ext4 /dev/sdb1
Rootfs - Debian 8 Small flash
Created EXT4 partition is for Alpine Linux. Just copy whole files into the partition.
$ sudo mount /dev/sdb1 /mnt/
Generate uEnv.txt file.
##This will work with: Angstrom's 2013.06.20 u-boot.
loadaddr=0x82000000
fdtaddr=0x88000000
rdaddr=0x88080000
initrd_high=0xffffffff
fdt_high=0xffffffff
#for single partitions:
mmcroot=/dev/mmcblk0p1
loadximage=load mmc 0:1 ${loadaddr} /boot/vmlinuz-grsec
loadxfdt=load mmc 0:1 ${fdtaddr} /boot/dtbs/am335x-boneblack.dtb
loadall=run loadximage; run loadxfdt;
mmcargs=setenv bootargs console=tty0 console=${console} ${optargs} ${cape_disable} ${cape_enable} root=${mmcroot} rootfstype=${mmcrootfstype} ${cmdline}
uenvcmd=run loadall; run mmcargs; bootz ${loadaddr} - ${fdtaddr};
Move it into the rootfs.
$ sudo cp uEnv.txt /mnt/
Download the prebuilt Debian 8 rootfs compressed file and extract it
$ wget -c https://rcn-ee.com/rootfs/eewiki/barefs/debian-8.5-bare-armhf-2016-08-16.tar.xz
$ tar xf debian-8.5-bare-armhf-2016-08-16.tar.xz
Copy rootfs into the SD card
$ sudo tar xfvp armhf-rootfs-debian-jessie.tar -C /mnt/
$ ls -la /mnt/
total 100
drwxr-xr-x 21 root root 4096 Aug 16 23:30 .
drwxr-xr-x 24 root root 4096 Sep 26 23:36 ..
drwxr-xr-x 2 root root 4096 Aug 16 23:28 bin
drwxr-xr-x 3 root root 4096 Aug 16 23:30 boot
drwxr-xr-x 4 root root 4096 Aug 16 23:26 dev
drwxr-xr-x 49 root root 4096 Aug 16 23:30 etc
drwxr-xr-x 3 root root 4096 Aug 16 23:30 home
drwxr-xr-x 12 root root 4096 Aug 16 23:27 lib
drwx------ 2 root root 16384 Sep 28 10:42 lost+found
drwxr-xr-x 2 root root 4096 Aug 16 23:26 media
drwxr-xr-x 2 root root 4096 Aug 16 23:26 mnt
drwxr-xr-x 3 root root 4096 Aug 16 23:30 opt
drwxr-xr-x 2 root root 4096 May 30 13:40 proc
drwx------ 2 root root 4096 Aug 16 23:26 root
drwxr-xr-x 2 root root 4096 Apr 7 2015 run
drwxr-xr-x 2 root root 4096 Aug 16 23:29 sbin
drwxr-xr-x 2 root root 4096 Aug 16 23:26 srv
drwxr-xr-x 2 root root 4096 Apr 7 2015 sys
drwxrwxrwt 2 root root 4096 Aug 16 23:30 tmp
-rw-r--r-- 1 root root 596 Sep 28 10:43 uEnv.txt
drwxr-xr-x 10 root root 4096 Aug 16 23:26 usr
drwxr-xr-x 11 root root 4096 Aug 16 23:26 var
Copy new dtb file into the SD card.
$ sudo mkdir /mnt/boot/dtbs/
$ sudo cp arch/arm/boot/dts/am335x-boneblack.dts.dtb /mnt/boot/dtbs/
Copy new built Linux kernel.
$ sudo cp arch/arm/boot/zImage /mnt/boot/vmlinuz-grsec
Done! Just pull out the SD card to test new kernel on BBB.
$ sync
$ sudo umount /mnt