how to start serial console on imx53 linux?

[hiromitakano]

Hello,

I'm using a custom board, based on the START-R board, and I can succesfully start u-boot and kernel 2.6.35 on it. I load uImage, u-boot and initramfs on an sd-card, I send the boot command and then I see the output from the kernel, until it arrives at the message "feed watchdog", which is written periodically on the output. I would expect a serial console, like the one given by the quick start board...

Please, could anybody help me to find out what I could have missed?

[lily_zhang]

You had better check your "console" setting into bootloader. And use the right console output.

[hiromitakano]

Do you mean the console environment variable in u-boot? I've set it at console=ttymxc1, i.e. UART2, and I'm sure it works, because other messages from the kernel are correctly sent to this serial interface (e.g. the "feed watchdog" one).

[lily_zhang]

So I guess you flash the ram rootfs for MFGTool instead of the normal rootfs for booting.

Please flash the right default rootfs.

[hiromitakano]

Thank you for your answer, after compiling and depoloying I load these files onto sd-card for booting:

ltib/rootfs/boot/u-boot.bin

ltib/rootfs/boot/uImage

ltib/initramfs.cpio.gz.uboot.

If the latter is not the right initramfs where should I find the right one?

[lily_zhang · Accepted solution]

I assumed that you are using ltib. So you can input the following command line:

./ltib -m selectype

Select as the followings:

│ │          --- Choose the platform type                              │ │

  │ │              Selection (imx5x)  --->                                │ │

  │ │          --- Choose the packages profile                            │ │

  │ │              Selection (FSL gnome release package)  --->

If you just want to try a minimum rootfs, you can select “Minimum bootable root filesystem”.

Then “Save” it. You can see another prompt menu. Select as the followings:

│--- Target System Configuration                                      │ │

  │ │    Options  --->

You can see the followings:

│(freescale) target hostname                                          │ │

  │ │[*] boot up with a tty and login                                    │ │

  │ │(::respawn:/sbin/getty -L ttymxc0 115200 vt100)