COM iMX25 Bootloader U-Boot

FAQ

Q: Entering Bootloader console is not possible?

A: Up to U-Boot version V1.14.0.0 it was possible to enter the bootloader console by pressing any key (e.g. "Enter"). Since version V1.15.0.0 it is not possible to enter to the bootloader console by pressing a various key (e.g. "Enter") anymore. You have to send "DEL" (ASCII 0x7F) to the device. We recommend you to use the terminal program teraterm if you are working on windows and to use kermit or minicom if you use linux on your pc.

You can configure teraterm to send "DEL" when the delete key or the backspace key is pressed by clicking through the menu to Setup->Keyboard-Setup and enable the required checkbox.

Kermit is sending a "DEL" if you hit the backspace key.

Minicom is able to send "DEL" when you hit the backspace key if you configure minicom to do that within a terminal window:

`$ minicom -s`
navigate to `Screen and keyboard`
press "B"

Q: Update from U-Boot V1.11.2.0 to V1.14.0.0 or higher?

A: Follow the six steps:

Copy new U-Boot binary to MicroSD Card
Insert MicroSD Card to core module and connect DHCOM UART1 to host PC
Start core module and enter bootloader console by pressing "del" during start
Call the command "nand erase c0000 bffff" and press enter
Call the command "update bootloader" and press enter
Restart the core module. The bootloader is updated now.

Q: Update from U-Boot V1.5.0.0 or V1.7.0.0 to V1.14.0.0 or higher?

A: Follow the sixsteps:

Copy new U-Boot binary, splash bitmap, new settings binary and DHupdate.ini file to MicroSD Card
DHupdate.ini file [update] content:
splash *.bmp

settings *.bin
Insert MicroSD Card to core module and connect DHCOM UART1 to host PC
Start core module and enter bootloader console by pressing "del" during start
Call the command "nand erase 80000 3ffff" and press enter
Call the command "update bootloader u-boot.bin" and press enter
After Update restart the core module and wait until bootloader has updateted splashimage and settings block (to prevent update repetition delete the update files from MicroSD Card after a successful update)

Note: It is neccessary to flash the OS image again, if OS image was already flashed before bootloader update.

Changelog

Changelog Files

Downloads

Please have a look at the iMX25 Downloads section.

Enter Bootloader Console

Connect DHCOM UART1 via null modem cable to the Host PC
Start terminal program (recommended terminal program: TeraTerm) on the Host PC with the following settings:
Baud rate: 38400

Data: 8 bit

Parity: none

Stop bits: 1 bit

Flow control: none
Press "del" on the Host PC during Core Module system start to enter bootloader console

U-boot console commands

NAND-Flash

Read from NAND-Flash Device

`nand read <SDRAM address> <NAND Flash address> <Bytes>`

Example: nand read 80000000 400000 b40000

Description: Copies 11,25MByte from NAND Flash address 0x40_0000 to SDRAM address 0x8000_0000

Erase NAND-Flash blocks

`nand erase <Block base address> <Bytes>`

Example: nand erase 400000 40000

Description: Deletes NAND Flash content from address 0x40_0000 to 0x43_FFFF

Note: The Bytes information needs to be block size aligned!

Write to NAND-Flash Device

`nand write <SDRAM address> <NAND-Flash address> <Bytes>`

Example: nand write 80000000 400000 b40000

Description: Copies 11,25MByte from SDRAM address 0x8000_0000 to NAND Flash address 0x40_0000

Note: The Bytes information needs to be page size aligned!

Show bad NAND-Flash blocks

`nand bad`

Description: Shows the bad NAND-Flash blocks.

Show NAND-Flash content

`nand dump <NAND-Flash address>`

Example: nand dump 400000

Description: Shows the content of the specified NAND-Flash block

SPI Flash

Only available at iMX25

SPI Flash Init

`sf probe <bus:cs> [frequency]`

Example: sf probe 0:1

Description: Initializes the OnBoard SPI Flash

SPI Flash Read

`sf read <SDRAM address> <SPI Flash address> <Bytes>`

Example: sf read 80000000 40000 10000

Description: Copies 64kByte from SPI Flash address 0x4_0000 to SDRAM address 0x8000_0000

SPI Flash Write

`sf write <SDRAM address> <SPI Flash address> <Bytes>`

Example: sf write 80000000 40000 10000

Description: Copies 64kByte from SDRAM address 0x8000_0000 to SPI Flash address 0x4_0000

SPI Flash Erase

`sf erase <SPI Flash address> <Bytes>`

Example: sf erase 40000 10000

Description: Deletes SPI Flash content from address 0x4_0000 to 0x4_FFFF

Note: The Bytes information needs to be sector size aligned!

LCD contoller

Show LCD controller settings

`lcdinfo`

Example output:

 Display Resolution: 800 x 480 pixels
 Display Type:       Active Color Display
 Pixel Clock:        22 MHz
 Bits per Pixel:     16 Bits/Pixel
 Pixel Polarity:     Active High
 VSYNC Polarity:     Active Low
 HSYNC Polarity:     Active Low
 Clock Polarity:     Pos. Edge
 Output En Polarity: Active High
 HSYNC Puls Width:   64 Clock Cycles
 HSYNC Back Porch:   86 Clock Cycles
 HSYNC Front Porch:  42 Clock Cycles
 VSYNC Puls Width:   2 Line Cycles
 VSYNC Back Porch:   33 Line Cycles
 VSYNC Front Porch:  10 Line Cycles

GPIO's

Show DHCOM GPIO settings

`gpioinfo`

Example output:

 GPIO_A: Direction = Input
         State     = 0
 GPIO_B: Direction = Input
         State     = 0
 GPIO_C: Direction = Input
         State     = 0
 GPIO_D: Direction = Input
         State     = 0
 GPIO_E: Direction = Input
         State     = 1
 GPIO_F: Direction = Input
         State     = 1
 GPIO_G: Direction = Output
         State     = 1
 GPIO_H: Direction = Input
         State     = 1
 GPIO_I: Direction = Input
         State     = 1
 GPIO_J: Direction = Input
         State     = 1
 GPIO_K: Direction = Input
         State     = 0

SD/MMC Card

DHCOM iMX25:

Switch between MicroSD and SD Slot

`mmcswitch <Slot number>`

Example: mmcswitch 2

Description: Switch between SD/MMC Slots: 1 --> SD/MMC Slot, 2 --> MicroSD Slot

Initialize SD/MMC Card

`mmcinit`

Description: Initialize new inserted SD Card

DHCOM AM35:

Switch between onboard microSD Slot and external SD - Card interface

`mmc switch <Slot number>`

Example: mmc switch 2

Description: available interfaces

1 --> external SD/MMC Slot
2 --> onboard microSD Slot

Initialize SD/MMC Card

`mmc init`

Description: Initialize new inserted SD Card

FAT - Filesystem

Show Filesystem information

`fatinfo <interface> <device>`

Example: fatinfo mmc 1

Interface: MMC
 Device 1: Vendor: Man 094150 Snr 266e068c Rev: 1.0 Prod: AF UD
           Type: Removable Hard Disk
           Capacity: 121.2 MB = 0.1 GB (248320 x 512)
 Partition 1: Filesystem: FAT16 "NO NAME    "

List files

`fatls <interface> <device> <directory>`

Example 1: fatls mmc 1

Example 2: fatls mmc 1 /folder

Load Files from SD Card to SDRAM

`fatload <interface> <device> <SDRAM address> <directory+filename>`

Example 1: fatload mmc 1 80100000 nk.gz

Example 2: fatload mmc 1 80100000 /folder/nk.gz

Ethernet

Load File via TFTP to SDRAM

`tftp <SDRAM address> <directory+filename>`

Example: tftp 80100000 nk.gz

Example TFTP Server: "Winagents TFTP Server Manager"

Note: For TFTP download it is necessary to config the ENV variables "ipaddr" and "serverip"

Load File via TFTP to SDRAM using DHCP

`dhcp <SDRAM address> <directory+filename>`

Example: dhcp 80100000 nk.gz

Example TFTP Server: "Winagents TFTP Server Manager"

Note: It is necessary to config the ENV variable "serverip" with the ip-address of your TFTP-Server

Ping

`ping <IP address>`

Example: ping 192.168.55.32

Read PHY register via MII interface

`mii dump <PHY address> <PHY register>`

DHCOM iMX25:

Example: mii dump 1 0

Description: Shows PHY control register content.

DHCOM AM35:

Example: mii dump 0 0

Remark: The standard MII registers 0-5 are supported by this command. When you are working with a DHCOM AM35 module only PHY address "0" is allowed.

Environment

Show ENV variables

`printenv`

bootdelay=0
baudrate=38400
ipaddr=192.168.55.230
serverip=192.168.55.36
gatewayip=192.168.55.36
netmask=255.255.255.0
frias=5
kernel=uImage
bootargs=console=ttymxc0,115200 root=/dev/mmcblk0p2
nandbootwince=update;bootwince 00200000
splashimage=0x000c0000
save_ENV_to_flash=setenv ENVinFlash 1; saveenv
ENVinFlash=1
ethaddr=00:04:a3:34:b6:0d
ethact=FEC0
winceimagetype=nk.gz
winceimagesize=00ba55ee
loadaddr=00200000
bootcmd=run nandbootwince
filesize=212050
Environment size: 449/262140 bytes

Set ENV variables

`setenv <ENV name> <ENV value>`

Example: setenv ipaddr 192.168.55.2

Note: If you need to edit "bootcmd" it is necessary to insert ";" between the unique commands. You can enter ";" at the command line with "\;".

Save ENV variables

`saveenv`

Erase all ENV variables

`eraseenv`

Note: It is necessary to restart the system after "eraseenv", to restore the default ENV settings.

Update

`update <type> [filename]`

Type:

auto = Start the automatic update with a DHupdate.ini file.

wince = WinCE image update (default file names nk.gz or nk.bin) + ENV update

linux = Linux image update (default file name uImage) + ENV update (default script file name uImage.env)

Remark:The ENV update script must have the same filename as the linux-kernel with the ending ".env". It is possible to update the environment of u-boot without a kernel update by inserting the filename of the ENV script.

rootfs = Create or replace the root-filesystem in the NAND-Flash (default file name fsroot.tar.gz). The rootfs update has to be the last item (or second to last item if you insert the reset command) in the DHupdate.ini file.

Remark: To run a "NAND-Flash root-filesystem update" you need a special linux-kernel which must have the filename "uImage.update" and must be available in the same diretory on your update-media as the DHupdate.ini file.

flash = Complete flash image update

bootloader = Bootloader update (default file name u-boot.bin)

splash = Bootbitmap update (default file name splash.bmp)

settings = Settings block update (default file name settings.bin)

eeprom = Display-Settings block update (default file name eeprom.bin)

reset = Execute a reset after a successfull update. A reset can only be the last item in a DHupdate.ini file.

Remark: Be careful with the reset command. You can easily build a endless update loop by mistake.

For further information look at DHCOM Flash Update.

I2C

List available devices

`i2c probe`

Valid chip addresses: 00 57 6F
0x5F = DHCOM i.MX25 Core Module EEPROM
0x6F = DHCOM i.MX25 Core Module Real Time Clock

Read

`i2c md <I2C address> <start address> <end address>`

Example: i2c md 57 10 20

Description: Reads 16 Bytes from the address 0x10 to address 0x20.

Write

`i2c mw <I2C address> <I2C register> <Value> <Bytes>`

Example: i2c mw 57 0 aa 5

Description: Writes 0xaa to 5 Bytes from the offset 0.

OS Boot

WinCE

`bootwince <Image address> [debug]`

Example: bootwince 200000

Description: The address 0x20_0000 specifies NAND Flash image address. The image is loaded from NAND flash to SDRAM. Next to that u-boot starts WinCE. The "debug" option make sure that the image wouldn't be started after uncompressing.

Note: The Image address could also be an SDRAM address. But it is necessary to copy the Image (via tftp or nand flash commands) to the SDRAM before calling "bootwince".

`bootwince tftp`

Note: The ENV variables "loadaddr" and "bootfile" needs to be set before calling the command. For *.gz image types the "loadaddr" should be set to 0x8290_0000 and for *.bin images the address should be 0x8100_0000.

Linux

`bootm <Kernel address> [arg]`

Note: When booting a Linux kernel,‘arg' can be the address of an initrd image.

Unzip

`unzip <source address> <destination address>`

Example: unzip 82900000 80100000

Note: The unzip command is supporting the gzip file format.

Bitmap

Information

`bmp info <Bitmap address>`

Image size    : 800 x 480
Bits per pixel: 8
Compression   : 0

Display

`bmp display <Bitmap SDRAM address> [x y]`

Memory

Display

`md[.b, .w, .l] <address> [count]`

Example: md.b 80100000 100

Write

`mw[.b, .w, .l] <address> <value> [count]`

Example: mw.b 80100000 aa 100

Description: Writes the value 0xaa to the next 0x100 bytes from the address 0x8010_0000.

Copy

`cp[.b, .w, .l] <source> <destination> <count>`

Show DHCOM Settings

`settings`

Example:

 VALIDATION_ID:    "DH"
 DISPLAY_ID:       0x00
 LENGTH:           0x2c
 X_RESOLUTION:     800 pixel
 Y_RESOLUTION:     480 pixel
 PIXEL_CLOCK:      22200 kHz
 LCD_CONFIG_FLAGS: 0x3e3
 HSW:              64 pixel clocks
 VSW:              2 line clocks
 HFP:              42 pixel clocks
 HBP:              86 pixel clocks
 VFP:              10 line clocks
 VBP:              33 line clocks
 DATALINES:        16
 ACB:              0
 ACBI:             0
 GPIO_DIR:         0x01ff
 GPIO_STATE:       0x0000
 HW_CONFIG_FLAGS:  0x001e

NAND Flash allocation