No debug print after Linux kernel starting OMAPL138

Itamar Fimat1

Other Parts Discussed in Thread: OMAPL138, DA8XX

Hello,

I do not get output after line Starting kernel ...

I have found the relevant Troubleshooting page in the TI Wiki, a couple of posts here but so far failed to get the prints.

My u-boot configuration

bootargs console=ttyS0,115200n8 root=/dev/nfs noinitrd nfsroot=10.0.0.45:/var/www/share/fs,nolock,rsize=1024,wsize=1024 ip=10.0.0.148

In the hardware low level initialization code (head.S) I did following

setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode
@ and irqs disabled

mrc p15, 0, r9, c0, c0 @ get processor id
bl __lookup_processor_type @ r5=procinfo r9=cpuid
movs r10, r5 @ invalid processor (r5=0)?

#if 0
THUMB( it eq ) @ force fixup-able long branch encoding
beq __error_p @ yes, error 'p'
#endif

I tried also to patch hard coded arguments ttyS0 in the file board-omapl138-hawk.c, function omapl138_hawk_console_init()

I will appreciate any help.

Thank you.

over 11 years ago

0 Titusrathinaraj Stalin over 11 years ago

TI__Guru** 116100 points

Hi,

Have you enabled "early printk" support in menuconfig ?

Have you checked machine ID between kernel & u-boot ?

Have you modified the default UART port which is used by both kernel and u-boot?

What are all the changes have you done in linux, u-boot, & from hardware ?

http://processors.wiki.ti.com/index.php/Kernel_-_Common_Problems_Booting_Linux

bootargs console=ttyS0,115200n8 root=/dev/nfs noinitrd nfsroot=10.0.0.45:/var/www/share/fs,nolock,rsize=1024,wsize=1024 ip=10.0.0.148

If you are using UART0 then "console=ttyS0" and if UART1 used as console in your board then "console=ttyS1" respectively.

I presume that you have modified the default UART console port, Please confirm.

0 Itamar Fimat1 over 11 years ago in reply to Titusrathinaraj Stalin

Prodigy 130 points

Hi,

Have you enabled "early printk" support in menuconfig ?

Yes

Have you checked machine ID between kernel & u-boot ?

I closed with #if 0 the code which breaks the start up if the ID is not consistent

I used UART0 in our custom board.

0 Itamar Fimat1 over 11 years ago in reply to Titusrathinaraj Stalin

Prodigy 130 points

BTW,

CONFIG_DEBUG_LL is enabled but still no prints are observed.

0 Titusrathinaraj Stalin over 11 years ago in reply to Itamar Fimat1

TI__Guru** 116100 points

Hi,

Refer the following e2e thread which has the answer to support UART0 as a console.

Have you modified the u-boot source as well for UART0 console ?

http://e2e.ti.com/support/embedded/linux/f/354/t/59241.aspx

0 Itamar Fimat1 over 11 years ago in reply to Titusrathinaraj Stalin

Prodigy 130 points

Hi Titus,

Thank you very much for the quick answer!

I did everything I found in articles you have provided. But the picture is the same:

## Booting kernel from Legacy Image at c0700000 ...

Image Name: Linux-3.1.10-gb6b7318-dirty

Image Type: ARM Linux Kernel Image (uncompressed)

Data Size: 2042792 Bytes = 1.9 MiB

Load Address: c0008000

Entry Point: c0008000

Verifying Checksum ... OK

kernel data at 0xc0700040, len = 0x001f2ba8 (2042792)

## No init Ramdisk

ramdisk start = 0x00000000, ramdisk end = 0x00000000

Loading Kernel Image ... OK

kernel loaded at 0xc0008000, end = 0xc01faba8

## Transferring control to Linux (at address c0008000) ...

Starting kernel ...

I've attached my .config file (renamed to kernel.config) uncompress.h and debug-macro.S.

Thanks again for your help.

files.tar.gz

0 Titusrathinaraj Stalin over 11 years ago in reply to Itamar Fimat1

TI__Guru** 116100 points

Hi,

Have you modified the board file for accessing the UART0 console instead UART2?

1) Shutdown the UART2 & Enable UART0

__raw_writel(0, IO_ADDRESS(DA8XX_UART0_BASE) + 0x30);

__raw_writel(0, IO_ADDRESS(DA8XX_UART2_BASE) + 0x30);

2) Enable UART0 console

return add_preferred_console("ttyS", 2, "115200");

return add_preferred_console("ttyS", 0, "115200");

0 Titusrathinaraj Stalin over 11 years ago in reply to Titusrathinaraj Stalin

TI__Guru** 116100 points

Hi,

In addition to that revert back the changes which you done in 'uncompress.h' and debug-macro.S' files and follow only the above mentioned changes.

Please ensure that you have done proper pinmuxing for UART0 and keep in mind that UART0 is pinmuxed with EMAC(MII).

0 Itamar Fimat1 over 11 years ago in reply to Titusrathinaraj Stalin

Prodigy 130 points

Hi and thanks again,

Did all the things you have suggested, but with the same result.

I've attached my board file with all changes I did.

Thanks.

0 Itamar Fimat1 over 11 years ago in reply to Titusrathinaraj Stalin

Prodigy 130 points

Hi Titus,

The things start work, thanks!

0 Titusrathinaraj Stalin over 11 years ago in reply to Itamar Fimat1

TI__Guru** 116100 points

Hi Itamar,

I'm glad that you able to boot your board through UART0.

Thanks for your update.

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No debug print after Linux kernel starting OMAPL138