Unable to get SCC 4 working as a console port on a 8260ADS

Stan Partridge SPartridge at CTDI.COM
Fri Apr 30 08:47:45 EST 2004

I am a newbie to Embedded linux and I am unable to get SCC4 working as my
console device for my custom board.  I am using Linux 2.4.24 from ELDK 3.0.
U-boot works greats with SCC4 defined as my console device.  I must use SCC4
as my console device because my board has no more pins left that I can use.
In addition, I can not use the hardware handshaking pins as well.  I only
have the 2 wires - Rx and Tx available. I am using all 3 FCCs and using an
SMC as a serial port is not an option due to its intensive FSM and drag on
the CP.

I attemptted to boot linux but it traps at console_printk.  After the trap,
the SCC4 Registers look good to me so I guess the port has been initialized:

GSMR_L4    00028034    Tx and Rx enabled
GSMR_H4    00000020
PSMR4        B000
TODR4         8000
DSR4           7E7E
SCCE4         0107
SCCM4        0000
SCCS4         03

The log_buf contains the following:

devfs: v1.12c (20020818) Richard Gooch (rgooch at atnf.csiro.au)
devfs: boot_options: 0x1
CPU UART driver version 0.01
ttyS0 on SCC1 at 0x8000 BRG7
ttyS1 on SCC2 at 0x8100 BRG1
pty: 256 Unix98 ptys configured
Serial driver version 5.05c (2001-07-08) with MANY_PORTS enabled
Oops: kernel access of bad area, sig: 11
NIP: C00E8EF4  XER: 0000000 LR: C00ED804 SP: C039FE90 REGS: C039FDE0
TRAP:0300 Not tainted
TASK= c039e000[1] 'swapper' Last syscall: 120
last math 00000000 last altivec 00000000
GPR0: ......
Call backtrace:
 c0198e60 - console_printk
 c01b7e58 - early_serial_setup
 c01af63c - do_initcalls
 c01af684 - do_basic_setup
 c00039d0 - init
 c0008338 - arch_kernel_thread
Kernel panic: Attempted to kill init!
Rebooting in 180 seconds.

A few seconds later the console terminal spews pages and pages of the
following junk:


I'm using the uRamdisk (SELF) image found in ELDK 3.0 as my ram disk.  My
boot session and config files are attached

Any suggestions on how I should preceed?

Thanks in advance!
Stan Partridge

 <<bootSession.txt>>  <<ads8260-fs.config>> 

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