Am Dienstag, den 07.08.2012, 15:28 -0700 schrieb Allen Martin:
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.
Yes I can confirm this fixes the issue without further workarounds. Thanks, and:
Tested-by: Lucas Stach dev@lynxeye.de
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,memorymov lr, ip @ restore linkmov pc, lr @ back to my caller-ENDPROC(cpu_init_crit) -#endif
#ifndef CONFIG_SPL_BUILD /*