The goal of the document is to illustrate how to create an SD card with SP7021 Linux kernel and root file-system. Please follow the following steps.
1. Download source files
Get latest source files from git server of SP7021 (2. HOW TO GET SOURCE FILE AND PACKAGE). Refer to report of ll command for the contents of top folder of source of SP7021:
wells@wells-linux:~/q628/sdc$ ll total 52 drwxrwxr-x 12 wells wells 4096 Dec 5 00:42 ./ drwxrwxr-x 12 wells wells 4096 Oct 16 23:01 ../ drwxrwxr-x 8 wells wells 4096 Jun 7 19:59 boot/ drwxrwxr-x 4 wells wells 4096 Nov 20 23:10 build/ drwxrwxr-x 7 wells wells 4096 Jul 27 18:53 crossgcc/ drwxrwxr-x 6 wells wells 4096 Jun 7 19:59 eCos/ drwxrwxr-x 9 wells wells 4096 Jun 15 21:52 freertos/ drwxrwxr-x 8 wells wells 4096 Dec 4 23:02 ipack/ drwxrwxr-x 7 wells wells 4096 Jun 7 19:59 linux/ -r--r--r-- 1 wells wells 23 Jun 7 19:59 Makefile drwxrwxr-x 4 wells wells 4096 Jun 7 19:59 nonos/ drwxrwxr-x 7 wells wells 4096 Jun 7 19:59 .repo/ drwxrwxr-x 3 wells wells 4096 Jun 27 16:34 yocto/
2. Configure environment
Get latest source files of SP7021 from git server of SP7021 (2. HOW TO GET SOURCE FILE AND PACKAGE) and run make config command on top folder. After configuration menu pops up, first, choose board you want to build image for. For example, press 4 for SP7021 Demo Board (V3). Second, press 2 to choose to build image for SD card and then enter to start to configure building environment. Refer to screenshot below:
make config is starting to configure building environment. It takes 1~2 minutes to complete.
3. Build all images
Run make all command to start to create image for SD card. It might take several minutes to complete. After 'make all' completes, you will see screen like:
From information on screenshot, two partitions are created in the image of SD card. The first partition starts at sector 2,048 and ends at sector 264,191. Its size is 128 MiB and file-system is W95 FAT32. The second partition starts at sector 264,192 and ends at sector 299,007. Its size is 17 MiB and file-system is Linux (ext4).
4. Image files
The built image files are stored at out/boot2linux_SDcard/. Refer to screenshot of list of the folder:
ISPBOOOT.BIN is a binary file in which xboot is stored. xboot is a boot-loader which loads and runs u-boot during power-on booting processes. u-boot.img is u-boot image file. u-boot is the second stage boot-loader. It loads and runs Linux kernel image. uImage is an image file of compressed Linux kernel with u-boot header. uEnv.txt is an environment file of u-boot. u-boot imports environment variables in the file after it completes initializing. If uenvcmd command is defined in uEnv.txt, u-boot runs the uenvcmd command after it completes importing uEnv.txt. a926.img is an image file for processor A926. A926 processor is designed for taking care of real-time tasks. The default script of u-boot will load and run a926.img it if it exists in root of boot partition.
ISP_SD_BOOOT.img is an image for burning an SD card. It actually contains all files in both partitions.
5. Write image to an SD card
Use an application to write image file, ISP_SD_BOOOT.img, to an SD card. The capacity of SD card should be larger than size of image file, ISP_SD_BOOOT.img. For example, if you want to use “Win32 Disk Imager” to write image to an SD card. First, download the it from https://sourceforge.net/projects/win32diskimager/:
Then, install and run it. After application window pops, select “Image File” and “Device”. Finally, press “Write” button to start to write. Refer to screenshot when “Win32 Disk Imager” is writing image file, ISP_SD_BOOOT.img, to an SD card (G:\) below:
Another example is using “balenaEtcher”. Refer to screenshot when “balenaEtcher” is writing image file, ISP_SD_BOOOT.img, to an SD card below:
6. Boot from an SD card
Insert your SD card to SP7021 board and set its DIP-SW to “boot from SD card”. For example, if you are using SP7021 Demo Board (V1/V2/V3), you need to set DIP-SW to ON-ON for booting from SD card. Refer to picture below:
DIP-SW is set to ON-ON. Refer to Selection of boot devices of SP7021 for details of boot selection.
Turn on power of SP7021 board to start booting.
7. Extend size of root file-system
At the first time, Linux boots from a new SD card. The built-in script of Linux will run fdisk command to extend the size of rootfs partition to the end of SD card and then re-boot. Refer to log while Linux script is extending size of rootfs partition:
[ 1.777157] EXT4-fs (mmcblk1p2): mounted filesystem with ordered data mode. Opts: (null)
[ 1.777419] VFS: Mounted root (ext4 filesystem) on device 179:18.
[ 1.781035] devtmpfs: mounted
[ 1.785128] Freeing unused kernel memory: 1024K
[ 1.854989] Run /sbin/init as init process
/etc/init.d/rcS starts...
Mounting other filesystems ...
rc.extra [bg]
sdcard boot set...
partition set
0x0000A52E
totalsize=15836643328
0x00000007
extra done
totalsize=30930936 startsector=264192
The number of cylinders for this disk is set to 483296.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): Disk /dev/mmcblk1: 15 GB, 15836643328 bytes, 30930944 sectors
483296 cylinders, 4 heads, 16 sectors/track
Units: sectors of 1 * 512 = 512 bytes
Device Boot StartCHS EndCHS StartLBA EndLBA Sectors Size Id Type
/dev/mmcblk1p1 0,32,33 16,113,33 2048 264191 262144 128M b Win95 FAT32
/dev/mmcblk1p2 16,113,34 18,156,10 264192 299007 34816 17.0M 83 Linux
Command (m for help): Partition number (1-4):
Command (m for help): Partition type
p primary partition (1-4)
e extended
Partition number (1-4): First sector (16-30930943, default 16): Last sector or +size{,K,M,G,T} (264192-30930943, default 30930943):
Command (m for help): Disk /dev/mmcblk1: 15 GB, 15836643328 bytes, 30930944 sectors
483296 cylinders, 4 heads, 16 sectors/track
Units: sectors of 1 * 512 = 512 bytes
Device Boot StartCHS EndCHS StartLBA EndLBA Sectors Size Id Type
/dev/mmcblk1p1 0,32,33 16,113,33 2048 264191 262144 128M b Win95 FAT32
/dev/mmcblk1p2 1023,3,16 1023,3,16 264192 30930936 30666745 14.6G 83 Linux
Command (m for help): The partition table has been altered.
Calling ioctl() to re-read partition table
fdisk: WARNING: rereading partition table failed, kernel still uses old table: Device or resource busy
End of /etc/init.d/rcS
[ 3.832704] EXT4-fs (mmcblk1p2): re-mounted. Opts: (null)
The system is going down NOW!
Sent SIGTERM to all processes
Sent SIGKILL to all processes
Requesting system reboot
[ 8.555816] reboot: Restarting system
sp_restart
+++iBoot v1.02 Jan 10 2019 11:20:28
The latest command in the script is reboot command. You’ll see system re-boots after script completes extending size of rootfs partition.
After system re-boots successfully, built-in script of Linux will run resize2fs to resize the root file-system to make use of the whole partition (It was extended in previous step.). Refer to log when resizing:
[ 1.715502] EXT4-fs (mmcblk1p2): mounted filesystem with ordered data mode. Opts: (null) [ 1.715821] VFS: Mounted root (ext4 filesystem) on device 179:2. [ 1.720053] devtmpfs: mounted [ 1.723384] Freeing unused kernel memory: 1024K [ 1.755834] Run /sbin/init as init process /etc/init.d/rcS starts... Mounting other filesystems ... rc.extra [bg] sdcard boot set... resize2fs partition 0x00008715 0x00000007 extra done Filesystem at /dev/mmcblk1p2 is mounted on /; on-line resizing required old_desc_blocks = 1, new_desc_blocks = 1 [ 2.106883] EXT4-fs (mmcblk1p2): resizing filesystem from 4352 to 3833343 blocks [ 2.336889] EXT4-fs (mmcblk1p2): resized filesystem to 3833343 The filesystem on /dev/mmcblk1p2 is now 3833343 (4k) blocks long. Filesystem Size Used Available Use% Mounted on /dev/root 14.5G 9.8M 14.5G 0% / devtmpfs 248.3M 0 248.3M 0% /dev tmpfs 248.8M 0 248.8M 0% /dev/shm tmpfs 248.8M 0 248.8M 0% /tmp End of /etc/init.d/rcS login[709]: root login on 'console' ~ #
Resizing has completed. Available size of root file-system is 14.5 GB. You are ready to use SP7021 Linux.
Appendix: How to extend size of rootfs partition to maximum manually?
1. Use fdisk to extend size of rootfs partition to end of the SD card.
Run fdisk as below:
fdisk /dev/mmcblk1
where SD card device is at /dev/mmcblk1.
a) Press p to list partitions of the SD card.
b) Press d and then 2 to delete the second (rootfs) partition.
c) Press p to list partitions of the SD card again.
d) Press n and, p, 2, 206848 and then 31116279 to add back the second (rootfs) partition. Note that 206848 is start-LBA while 31116279 is new end-LBA of the partition.
e) Press p to list partitions of the SD card again. Confirm modification of partitions.
f) Press w to write back partition to the SD card.
g) Run reboot command to re-boot system.
Refer to screenshot below:
2. Run resize2fs to extend size of file-system to make use the whole partition
Run resize2fs command as below:
resize2fs /dev/mmcblk1p2
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