Micro2440 Instructions for U-Boot and Linux
A brief introduction about how to get started with the Micro2440 boards and u-boot.
We are going to replace all contents of the NAND flash - so make sure to have a backup if there is any valuable data on your device.
We are going to replace all contents of the NAND flash - so make sure to have a backup if there is any valuable data on your device.
What we need
- Micro2440 SDK
- Linux PC (Windows would work as well but I'm not sure how to upload files to Vivi with it.)
- SD/MMC card
- Serial cable
- USB cable or JTAG (to replace vivi)
Replacing the Bootloader
We are going to use the bootloader in NOR flash for booting preparing the whole boot environment in NAND flash. Doing so we can create a new bad block table for the NAND flash which seems to be necessary for most of the board shipped.
We are going to copy u-boot into the RAM of the board and execute it there. u-boot will provide us all necessary features to prepare nand flash and copy itself there.
We are going to copy u-boot into the RAM of the board and execute it there. u-boot will provide us all necessary features to prepare nand flash and copy itself there.
1. Use your preferred serial terminal application and connect to the micro2440 SDK board "COM-0" port. The u-boot serial console communication parameters are 115200,8,n,1. Connect the USB client (B) plug of the board with an USB port of your PC. Make sure to set the boot selection switch to the 'NOR' position before you power on the board.
2. No need to build anything from source, the binaries are provided in the support kit linked here. Download and unpack this file.
3. When you turn on the board you should see a list of options from the Vivi bootloader the board is shipped with.
##### FriendlyARM BIOS for 2440 ##### [x] bon part 0 320k 2368k [v] Download vivi ...
Press 'q' to enter the Vivi shell.
4. Now you can enter the command to download the u-boot bootlader via USB.
Supervivi> load ram 0x31000000 239016 u USB host is connected. Waiting a download.
The second number is the length of the file in bytes. The number in this description is an example and needs to replaced with the correct length of the file you are actually uploading.
Upload the file from your PC. Note that you need to have root privileges to do this.
$ sudo ./s3c2410_boot_usb u-boot.bin
Ususally you get an error message before the program terminates. This can be ignored. At the Vivi shell you should see something like this:
Now, Downloading [ADDRESS:31000000h,TOTAL:239026] RECEIVED FILE SIZE: 239026 (116KB/S, 2S) Downloaded file at 0x31000000, size = 239016 bytes
5. Now we are going to jump to u-boot and prepare the NAND flash
go 0x31000000
You should see u-boot starting:
U-Boot 1.3.2-dirty-moko12 (Apr 16 2009 - 18:14:52)
I2C: ready
DRAM: 64 MB
Flash: 2 MB
NAND: Bad block table not found for chip 0
Bad block table not found for chip 0
64 MiB
*** Warning - bad CRC or NAND, using default environment
USB: S3C2410 USB Deviced
In: serial
Out: serial
Err: serial
MAC: 08:08:11:18:12:27
Hit any key to stop autoboot: 0Now we can prepare the NAND slash:
MINI2440 # nand scrub
NAND scrub: device 0 whole chip
Warning: scrub option will erase all factory set bad blocks!
There is no reliable way to recover them.
Use this command only for testing purposes if you
are sure of what you are doing!
Really scrub this NAND flash? <y/N>
Erasing at 0x3ffc000 -- 100% complete.
Bad block table not found for chip 0
Bad block table not found for chip 0
OKand
MINI2440 # nand createbbt
Create BBT and erase everything ? <y/N>
Skipping bad block at 0x03ff0000
Skipping bad block at 0x03ff4000
Skipping bad block at 0x03ff8000
Skipping bad block at 0x03ffc000
Creating BBT. Please wait ...6. We copy u-boot to NAND
MINI2440 # nand write 0x31000000 u-boot
NAND write: device 0 offset 0x0, size 0x40000 262144 bytes written: OK
7. Reset
Return the boot selection switch to the NAND setting and try your new installed u-boot. Right after reset the u-boot console should appear again.
Return the boot selection switch to the NAND setting and try your new installed u-boot. Right after reset the u-boot console should appear again.
Working with U-Boot
1. Create a dynamic environment:
MINI2440 # dynenv set 40000
2. Copy the *.jffs2 and the uImage file to the SD/MMC card and put it into the card slot of the Micro2440 SDK.
3. Populate the kernel partiton in NAND flash
At the u-boot prompt enter the following commands
At the u-boot prompt enter the following commands
MINI2440 # nand erase kernel MINI2440 # mmcinit MINI2440 # fatload mmc 0:1 0x31000000 uImage MINI2440 # nand write 0x31000000 kernel
4. Populate the filesystem partition in NAND flash
The 'filesize' environment variable holds the size of the last file read by the fatload command. Because its padded to a erase block boundary we can use this knowledge to deal with root filesystems of multiple size easily.
The 'filesize' environment variable holds the size of the last file read by the fatload command. Because its padded to a erase block boundary we can use this knowledge to deal with root filesystems of multiple size easily.
MINI2440 # nand erase root
MINI2440 # mmcinit
MINI2440 # fatload mmc 0:1 0x31000000 gpe-image-micro2440.jffs2
MINI2440 # nand write.jffs2 0x31000000 root ${filesize}5. Set the boot command and save the environment settings
MINI2440 # setenv bootcmd nboot.e kernel \; bootm MINI2440 # saveenv
If you have a board with 7" LCD you need to set (and save) this parameter:
MINI2440 # setenv bootargs root=/dev/mtdblock3 rootfstype=jffs2 console=ttySAC0, 115200 mini2440=1tb
6. Reset and boot the device
MINI2440 # reset
Some additional information
U-Boot partition layout
nr name size offset 0 u-boot 0x00040000 0x00000000 1 env 0x00020000 0x00040000 2 kernel 0x00500000 0x00060000 3 root 0x03aa0000 0x00560000
OpenOCD configuration
You can use this configuration to access your Micro2440 using the parallel port JTAG that comes with it.
interface parport parport_port 0x378 parport_cable triton jtag_speed 0 source [find target/samsung_s3c2440.cfg] telnet_port 4444 gdb_port 3333 reset_config trst_and_srst
Bootstrapping without a working bootloader
If you have a device without valid bootloader you can bootstrap it by running u-boot from ram. This procedure is a little bit tricky since the CPU needs some initialisation before you can write an u-boot executable to the RAM.
You will need the JTAG cable, OpenOCD 1.x and the lowlevel_foo.bin image included in the support kit.
You will need the JTAG cable, OpenOCD 1.x and the lowlevel_foo.bin image included in the support kit.
At the OpenOCD prompt follow this sequence:
Reset the CPU and let it wait
Reset the CPU and let it wait
> reset halt
Now we bring out initialisation commands in place.
> load_image /path/to/lowlevel_foo.bin 0 downloaded 332 byte in 0s 21899us
We set a breakpoint at the address in RAM the initialisation code jumps to after successful execution.
> bp 0x33f80000 4 hw breakpoint added at address 0x33f80000
Now let the CPU run. It will go through the initialisation and finally jump to our breakpoint.
> resume Target 0 resumed > Target 0 halted target halted in ARM state due to breakpoint, current mode: Supervisor cpsr: 0x600000d3 pc: 0x33f80000 MMU: disabled, D-Cache: disabled, I-Cache: enabled
Now that we have initialised RAM we can bring our bootloader in place. We copy it to the address where the CPU is waiting due to the breakpoint.
> load_image /path/to/u-boot.bin 0x33f80000
And we allow it continue execution...
resume
You should get an u-boot console on the serial port now.
Write the u-boot binary to the "u-boot" partition now. (Same commands like for the kernel, but
use the existing address 0x33f80000 and "u-boot" for the partition name.
Write the u-boot binary to the "u-boot" partition now. (Same commands like for the kernel, but
use the existing address 0x33f80000 and "u-boot" for the partition name.
There is a screencast [4] available that is based on this decription.
References
[1] LinuxMCE Wiki: http://wiki.linuxmce.org/index.php/Mini2440
[2] OpenMoko Wiki: http://wiki.openmoko.org/wiki/Bootloader#Using_JTAG_to_boot_from_RAM
[3] Mini Bringup Guide: http://code.google.com/p/mini2440/wiki/MiniBringup
[4] mini2440 screencast: http://www.youtube.com/watch?v=oi66srITOcA
[2] OpenMoko Wiki: http://wiki.openmoko.org/wiki/Bootloader#Using_JTAG_to_boot_from_RAM
[3] Mini Bringup Guide: http://code.google.com/p/mini2440/wiki/MiniBringup
[4] mini2440 screencast: http://www.youtube.com/watch?v=oi66srITOcA
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