Mini2440 questions

Sat Apr 2 11:31:53 EDT 2011

Hi Zoltán,

Zoltán Kócsi wrote:
> I've got two issues. One is barebox related:
>
> Does the current git master branch supposed to boot from NAND?
> Download, config (mini2440 defconfig + very little personalisation),
> compile. Boot from NAND *is* enabled in the config.

As long Sascha release a new barebox, the NAND boot feature of the mini2440 is 
still in next. Its going to be released in the May release.

So, you must still use the 'next' branch to get all S3C2440 related NAND boot 
changes.

> Load to RAM and start: starts up just fine.
> Boot from NAND: nothing.

Sure. The NAND driver for the S3C2440 CPU is still broken for other NAND types 
than small page ones.

> I looked at the actual binary image with objdump -d and it seems to
> initialise the PLL, the SDRAM controller and load the NAND into the
> RAM, then jump onto it. All that code is within the 4K StepStone range.
> However, nothing happens, the board is dead.

Yes, because the S3C2440 NAND driver loads the wrong content from the NAND.

> The other problem is not barebox related, but considering the audience
> of the list someone might have some ideas.
>
> Linux kernel, 2.6.37.2. Defconfig for mini2440. A fairly minimalistic
> kernel is then configured, dev. drivers for on-board stuff are static,
> everything else is modules. Low-level debug messages are enabled.
>
> Booting the kernel (using vivi...) hangs, just after the console is
> initialised:
>
> Copy linux kernel from 0x00060000 to 0x30008000, size = 0x002a0000 ...
> done
> zImage magic = 0x016f2818
> Setup linux parameters at 0x30000100
> linux command line is: "noinitrd root=/dev/mtdblock3 init=/linuxrc
> console=ttySAC0,115200"
> MACH_TYPE = 1999
> NOW, Booting Linux......
> Uncompressing Linux... done, booting the kernel.
> s3c24xx_serial_initconsole
> s3c24xx_serial_init_ports: initialising ports...
> s3c24xx_serial_init_port: port=c03a6378, platdev=c03b9ab0
> s3c24xx_serial_init_port: c03a6378 (hw 0)...
> resource c0397b10 (50000000..50003fff)
> port: map=50000000, mem=f7000000, irq=70 (70,71), clock=1
> s3c2440_serial_resetport: port=c03a6378 (50000000), cfg=c03b9a24
> s3c24xx_serial_init_port: port=c03a6434, platdev=c0398d00
> s3c24xx_serial_init_port: c03a6434 (hw 1)...
> resource c0397b48 (50004000..50007fff)
> port: map=50004000, mem=f7004000, irq=73 (73,74), clock=1
> s3c2440_serial_resetport: port=c03a6434 (50004000), cfg=c03b9a44
> s3c24xx_serial_init_port: port=c03a64f0, platdev=c0398db8
> s3c24xx_serial_init_port: c03a64f0 (hw 2)...
> resource c0397b80 (50008000..5000bfff)
> port: map=50008000, mem=f7008000, irq=76 (76,77), clock=1
> s3c2440_serial_resetport: port=c03a64f0 (50008000), cfg=c03b9a64
> s3c24xx_serial_init(c03a665c,c03a6628)
> s3c2440_serial_probe: dev=c03b9ab0
> s3c24xx_serial_probe(c03b9ab0, c03a6628) 0
> s3c24xx_serial_probe: initialising port c03a6354...
> s3c24xx_serial_init_port: port=c03a6378, platdev=c03b9ab0
> s3c24xx_serial_probe: adding port
> s3c2440_serial_probe: dev=c0398d00
> s3c24xx_serial_probe(c0398d00, c03a6628) 1
> s3c24xx_serial_probe: initialising port c03a6410...
> s3c24xx_serial_init_port: port=c03a6434, platdev=c0398d00
> s3c24xx_serial_probe: adding port
> s3c2440_serial_probe: dev=c0398db8
> s3c24xx_serial_probe(c0398db8, c03a6628) 2
> s3c24xx_serial_probe: initialising port c03a64cc...
> s3c24xx_serial_init_port: port=c03a64f0, platdev=c0398db8
> s3c24xx_serial_probe: adding port
>
> and then nothing. A LED on the board is blinking (two blinks, maybe
> 100ms apart, then about 200ms pause) but nothing comes out of the
> serial port. The LCD backlight is off and there doesn't seem to be
> either a splash image or debug info on it (console on LCD is enabled).
>
> The build environment is the latest buildroot, 4.5.2 gcc, 0.9.31 uClibc,
> everything is built from scratch (that's actually the aim of the whole
> excercise, to build a working Linux system on a Mini2440 HW from clean,
> up-to-date sources, not pre-built toolchains and pre-compiled packages
> or binary images).
>
> Any pointers would be highly appreciated.

1) do you use the mini2440 kernel command line parameter?

In the 'next' branch I added this comment into mini2440's config:
#
# "mini2440" kernel parameter
# 0 .. 9 = screen type
# b = backlight enabled
# t = touch enabled
# c = camera enabled
# Note: can be "minit2440= " if nothing of these components are connected
#
bootargs="console=ttySAC0,115200 mini2440=0tbc"

2) in 2.6.37 and 2.6.38 the serial console name is totally broken. There is a 
patch around to fix it.

From: Darius Augulis <augulis.darius at gmail.com>
Subject: serial: samsung: fix device name

Without this patch you must use a serial UART name of "/dev/s3c2410_serial0" 
to make it work. Ugly.

I will send you this patch offline.

Regards,
Juergen

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