Debugging OMAP kernel

Use early printk
Starting with v2.6.33-rc, early printk works on ARM. Recent earlier kernels should work if you apply commit 93fd03a8c6728b58879f8af20ffd55d9c32a778b.

To use the earlyprintk, just do the following:

1. Make sure you have the necessary .config options set

CONFIG_DEBUG_LL=y CONFIG_EARLY_PRINTK=y CONFIG_OMAP_LL_DEBUG_UART1=y
 * 1) CONFIG_OMAP_LL_DEBUG_UART2 is not set
 * 2) CONFIG_OMAP_LL_DEBUG_UART3 is not set

The LL_DEBUG_UART above is typically 1, but it's 3 on Nokia boards.

2. Edit the kernel CMDLINE in your .config to have "debug earlyprintk"

Optionally if you have a JTAG console, you can use CONFIG_DEBUG_ICEDCC instead LL_DEBUG_UART.