In the following section special commandline parameters for the TQMa35 kernel are given:

Selects desplay and configures backlight curve.

video=mx3fb:< EDT480272 | EVERVGG482270 | ETV570 | CLAA070LC0ACW | FG0700K5DSSWBG01 | AUOG104SN02 >

Configures the USB OTG controller

otg_mode=<host | device>

Configures the LVDS Transmitter at power up

default: 0 (Off)

lvds=<0 | 1>

Enable / Disable the eSDHC3 controller at power up

• default: emmc
• emmc: maps the pins, binds the driver and try detect card
• none: do nothing. Pins can be used freely only for TQMa35 without eMMC

emmc_mode=<none | emmc>

Framebuffer console and Bootlogo support are not compiled in. To test fuctionality you can use fbtest utility:

root@tqma35 $ fbtest 

All GPIO pins are exported using sysfs and are accessible using their value node.

To set an output write “0” or “1” to the value node of gpio n:

root@tqma35 $ echo "1" > /sys/class/gpio/gpio<n>/value 
root@tqma35 $ echo "0" > /sys/class/gpio/gpio<n>/value 

To query current state of gpio n:

root@tqma35 $ cat /sys/class/gpio/gpio<n>/value 

To switch the backlight sysfs file nodes are provided. Use

root@tqma35 $ echo "0" > /sys/devices/platform/mx3_sdc_fb/graphics/fb0/mx3_sdc_bl0/bl_power

to switch on and

root@tqma35 $ echo "1" > /sys/devices/platform/mx3_sdc_fb/graphics/fb0/mx3_sdc_bl0/bl_power

to switch off.

To dim the backlight sysfs files are provided.

To query max / current brightness use:

$ cat /sys/devices/platform/mx3_sdc_fb/graphics/fb0/mx3_sdc_bl0/max_brightness
$ cat /sys/devices/platform/mx3_sdc_fb/graphics/fb0/mx3_sdc_bl0/brightness

To dim the backlight use (value in the range of 1 … max_brightness):

$ echo "<value>" > /sys/devices/platform/mx3_sdc_fb/graphics/fb0/mx3_sdc_bl0/brightness

Make sure the following environment variables existing and are configured correctly:

• kernel: Filename for kernel image on TFTP server
• kernel_addr: Offset in NOR-flash where to store the kernel, depends on partitioning scheme

Configure update helper:

MX35 U-Boot > setenv prg_kernel tftpboot ${loadaddr} ${kernel}; erase ${kernel_addr} A02FFFFF; cp.b ${loadaddr} ${kernel_addr} ${filesize}; setenv filesize
MX35 U-Boot > saveenv

Now the kernel image can be updated using the following shortcut:

MX35 U-Boot > run prg_kernel

Make sure the following environment variables existing and are configured correctly:

• rootfs: Filename for rootfs image on TFTP server
• ramdisk_addr: Offset in NOR-flash where to store the rootfs, depends on partitioning scheme

MX35 U-Boot > setenv ramdisk_end a1ffffff (für 32MB Flash)
MX35 U-Boot > setenv prg_rootfs tftpboot ${loadaddr} ${rootfs}; erase ${ramdisk_addr} +${filesize}; ${ramdisk_addr} ${ramdisk_end}; cp.b ${loadaddr} ${ramdisk_addr} ${filesize}; setenv filesize
MX35 U-Boot > saveenv

Now the rootfs can be updated using the following shortcut:

MX35 U-Boot > run prg_rootfs