On Tue, Aug 07, 2012 at 10:53:00AM -0700, Lucas Stach wrote:
> Hi Allen,
>
> And to answer Tom's question: the failure was that the real U-Boot would
> not come up after the SPL. All I could see was the one line printed by
> the SPL and nothing more.
I think I found the problem. It's the following code from start.S:
ENTRY(cpu_init_crit)
/*
* Jump to board specific initialization...
* The Mask ROM will have already initialized
* basic memory. Go here to bump up clock rate and handle
* wake up conditions.
*/
mov ip, lr @ persevere link reg across
call
bl lowlevel_init @ go setup pll,mux,memory
mov lr, ip @ restore link
mov pc, lr @ back to my caller
ENDPROC(cpu_init_crit)
The "ip" register is not preserved across function calls, and the
CodeSourcery compiler is using it in lowlevel_init or one of the
functions it calls. This code was there before the SPL changes, but
wasn't being called because CONFIG_SKIP_LOWLEVEL_INIT was set, but now
it isn't.
Lucas, can you try the following change? I tested it on seaboard with
CodeSourcery arm-2011.09-70-arm-none-linux-gnueabi and I'm able to
boot a kernel.
Tom if this works we probably want to get it into your pull request to
Albert. CodeSourcery toolchain is probably used by a lot of people.
-Allen
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index 2506f27..02e47fa 100644
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -152,7 +152,7 @@ reset:
/* the mask ROM code should have PLL and others stable */
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
bl cpu_init_cp15
- bl cpu_init_crit
+ bl lowlevel_init @ go setup pll,mux,memory
#endif
/* Set stackpointer in internal RAM to call board_init_f */
@@ -339,29 +339,6 @@ ENTRY(cpu_init_cp15)
mov pc, lr @ back to my caller
ENDPROC(cpu_init_cp15)
-#ifndef CONFIG_SKIP_LOWLEVEL_INIT
-/*************************************************************************
- *
- * CPU_init_critical registers
- *
- * setup important registers
- * setup memory timing
- *
- *************************************************************************/
-ENTRY(cpu_init_crit)
- /*
- * Jump to board specific initialization...
- * The Mask ROM will have already initialized
- * basic memory. Go here to bump up clock rate and handle
- * wake up conditions.
- */
- mov ip, lr @ persevere link reg across
-call
- bl lowlevel_init @ go setup pll,mux,memory
- mov lr, ip @ restore link
- mov pc, lr @ back to my caller
-ENDPROC(cpu_init_crit)
-#endif
-
#ifndef CONFIG_SPL_BUILD
/*
*************************************************************************
--
nvpublic
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