On Thu, May 08, 2008 at 11:49:37AM -0500, Menon, Nishanth wrote:

Hi Sascha, Based on http://sourceforge.net/mailarchive/forum.php?thread_name=20080508151609.GB94... This is the second separate patch which introducing Machine dependent init lowlevel config.

Regards, Nishanth Menon

This introduces CONFIG_MACH_HAS_INIT_LOWLEVEL which is the opposite of the current CONFIG_SKIP_LOWLEVEL_INIT. CONFIG_SKIP_LOWLEVEL_INIT which was used by ARM platform configurations previously, is made platform independent configuration.

CONFIG_MACH_HAS_INIT_LOWLEVEL can be enabled to do board level initialization and disabled to allow U-Boot to function as the second level boot loader in certain scenarios by skipping SDRAM initialization.

Signed-off-by: Nishanth Menon x0nishan@ti.com

Index: u-boot-v2.git/arch/arm/cpu/start-arm.S

--- u-boot-v2.git.orig/arch/arm/cpu/start-arm.S 2008-05-08 11:22:08.000000000 -0500 +++ u-boot-v2.git/arch/arm/cpu/start-arm.S 2008-05-08 11:23:16.000000000 -0500 @@ -156,7 +156,7 @@ * because memory timing is board-dependend, you will * find a lowlevel_init.S in your board directory. */ -#ifndef CONFIG_SKIP_LOWLEVEL_INIT +#ifdef CONFIG_MACH_HAS_INIT_LOWLEVEL bl board_init_lowlevel #endif

Index: u-boot-v2.git/arch/m68k/cpu/start-mcfv4e.S

--- u-boot-v2.git.orig/arch/m68k/cpu/start-mcfv4e.S 2008-05-08 11:23:17.000000000 -0500 +++ u-boot-v2.git/arch/m68k/cpu/start-mcfv4e.S 2008-05-08 11:23:38.000000000 -0500 @@ -448,7 +448,7 @@ * * Do not jump/call other u-boot code here! */ -#ifndef CONFIG_SKIP_LOWLEVEL_INIT +#ifdef CONFIG_MACH_HAS_INIT_LOWLEVEL bsr.l board_init_lowlevel nop #endif @@ -512,7 +512,7 @@ nop #endif

-#ifndef CONFIG_SKIP_LOWLEVEL_INIT +#ifdef CONFIG_MACH_HAS_INIT_LOWLEVEL /* * Call other half of initcode in relocated code * Index: u-boot-v2.git/common/Kconfig =================================================================== --- u-boot-v2.git.orig/common/Kconfig 2008-05-08 11:24:02.000000000 -0500 +++ u-boot-v2.git/common/Kconfig 2008-05-08 11:27:07.000000000 -0500 @@ -72,6 +72,14 @@ Architectures that have additional initialization can enable this functionality.

+config MACH_HAS_INIT_LOWLEVEL

• bool
• default y
• prompt "Board has low level init"
• help

•  This entry skips the SDRAM initialising on many platforms.
  

•  It enables using U-boot as a second stage bootloader.
  

This has the same problems as stated in my last mail about ARCH_HAS_INIT_LOWLEVEL, although the situation is slightly different here. The user cannot decide whether the machine actually _has_ a lowlevel init function, it simply has or has not. The user only can decide whether he wants to use it after reading the help text (which describes the situation the wrong way around btw).

I have a feeling that this option is unnessecary anyway because when you look at the board_init_lowlevel functions you'll see that the board code detects at runtime whether or not they run from SDRAM and thus have to skip initialization. This way you can start the same U-Boot binary from SDRAM Flash or whatever which is a convenient thing to have.

I tend to remove these two options completely. Architectures and boards which do not need lowlevel init functions can just provide an empty function here. If we end up introducing many similar options on a board or architecture level we can still decide to turn them into common options.

So far arch_init_lowlevel is unused. I only introduced it because the original start.S had some S3C2400 #ifdefs here and I did not want to encourage anyone to put more architecture dependent stuff here.

BTW you can skip the defconfig bits in your patches. It's probably better when I regenerate them from time to time myself because otherwise we'll increase the risk of merge conflicts.

Regards, Sascha