[U-Boot-Users] ARM, bootm and bootargs

[U-Boot-Users] ARM, bootm and bootargs

[Curt Brune]

Hello,

I'm trying to pass command line arguments from u-boot to the kernel
for an ARM-based board.  Following the README I'm setting the
environment variable "bootargs" to the command line I want and booting
with the "bootm" command.

When the kernel boots it prints it's command line, which is still the
default command line.  I was expecting to the see the command line I
stored in the "bootargs" variable.

I poked around in u-boot/lib_arm/armlinux.c and it looks like I needed
to have CONFIG_CMDLINE_TAG defined in my config, which I did.

Is there anything else I need to do?  Something I'm missing?

Cheers,
Curt

-- 

========================================================================
 Curt Brune           | Phone   1.650.380.2528 |     Managing Principal
 curt at cucy.com        | WWW       www.cucy.com |           Cucy Systems
========================================================================
             Cucy Systems -- Software. Integration. Training.
========================================================================

[U-Boot-Users] ARM, bootm and bootargs

[George G. Davis]

On Tue, Jun 01, 2004 at 09:33:16AM -0700, Curt Brune wrote:
> Hello,
> 
> I'm trying to pass command line arguments from u-boot to the kernel
> for an ARM-based board.  Following the README I'm setting the
> environment variable "bootargs" to the command line I want and booting
> with the "bootm" command.
> 
> When the kernel boots it prints it's command line, which is still the
> default command line.  I was expecting to the see the command line I
> stored in the "bootargs" variable.
> 
> I poked around in u-boot/lib_arm/armlinux.c and it looks like I needed
> to have CONFIG_CMDLINE_TAG defined in my config, which I did.
> 
> Is there anything else I need to do?  Something I'm missing?

Grep & google around for BOOT_PARAMS. The phys address used for your target's
boot params area must agree between U-Boot and Linux sources.

HTH!

--
Regards,
George
> 
> Cheers,
> Curt
> 
> -- 
> 
> ========================================================================
>  Curt Brune           | Phone   1.650.380.2528 |     Managing Principal
>  curt at cucy.com        | WWW       www.cucy.com |           Cucy Systems
> ========================================================================
>              Cucy Systems -- Software. Integration. Training.
> ========================================================================
> 
> 
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[U-Boot-Users] ARM, bootm and bootargs

[Friedrich, Lars]

Curt Brune wrote something slightly offtopic and may the gods forgive me
for answering here, but hopefully this answer will prevent further
similiar questions:

> I'm trying to pass command line arguments from u-boot to the kernel
> for an ARM-based board.  Following the README I'm setting the
> environment variable "bootargs" to the command line I want and booting
> with the "bootm" command.
> 
> When the kernel boots it prints it's command line, which is still the
> default command line.  I was expecting to the see the command line I
> stored in the "bootargs" variable.
> 
> I poked around in u-boot/lib_arm/armlinux.c and it looks like I needed
> to have CONFIG_CMDLINE_TAG defined in my config, which I did.
> 
> Is there anything else I need to do?  Something I'm missing?

Assuming you are trying to boot uClinux and the 2.4.x kernel, then
you need to modify uClinux-dist/linux-2.4.x/arch/armnommu/kernel/arch.c

There you'll find MACHINE_START(NETARM, "NET+ARM). Within the MACHINE_START
and MACHINE_END sequence you need to add BOOT_PARAMS(<value>) (no semicolon at the
end please). And the value you have to enter is whatever is set in
file: u-boot/board/xxxx(modnet50?)/xxxx(modnet50?).c
function: int board_init (void)
variable: gd->bd->bi_boot_params=<value>

If compiled with bdinfo support, you can also type bdinfo at the u-boot command prompt.
boot_params is the currently set <value>.

The default value for the modnet50 board is f.e. 0x800. You just have to make sure
that it is indeed a valid ram address for your custom board (and that of course it
doesn't get overwritten when you boot linux).

Best regards,
Lars Friedrich

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