Marek, > -----Original Message----- > From: Marek Vasut [mailto:marek.va...@gmail.com] > Sent: Friday, February 17, 2012 1:57 AM > To: u-boot@lists.denx.de > Cc: Tom Warren; Tom Warren > Subject: Re: [U-Boot] [PATCH] arm: Tegra2: Fix ELDK42 gcc failure with > inline asm stack pointer load > > > The 4.2.2 gcc in the ELDK42 release doesn't like the direct SP load > > using a constant in tegra2_start. Break it up into 4 loads using mov & > > orr. > > > > Tested on my Seaboard T20-A03, U-Boot loads and runs OK. Also compiled > > all tegra2 builds with both gcc 4.2.2 and 4.4.1 OK. > > > > Signed-off-by: Tom Warren <twar...@nvidia.com> > > --- > > arch/arm/cpu/armv7/tegra2/ap20.c | 25 ++++++++++++++++++++----- > > 1 files changed, 20 insertions(+), 5 deletions(-) > > > > diff --git a/arch/arm/cpu/armv7/tegra2/ap20.c > > b/arch/arm/cpu/armv7/tegra2/ap20.c index 4c44bb3..d2bc0d5 100644 > > --- a/arch/arm/cpu/armv7/tegra2/ap20.c > > +++ b/arch/arm/cpu/armv7/tegra2/ap20.c > > @@ -298,11 +298,26 @@ void tegra2_start(void) > > writel(0xC0, &pmt->pmt_cfg_ctl); > > > > /* > > - * If we are ARM7 - give it a different stack. We are about to > > - * start up the A9 which will want to use this one. > > - */ > > - asm volatile("ldr sp, =%c0\n" > > - : : "i"(AVP_EARLY_BOOT_STACK_LIMIT)); > > + * If we are ARM7 - give it a different stack. We are about to > > + * start up the A9 which will want to use this one. > > + */ > > + /* > > + * Note that the 'ldr sp,CONSTANT' version, below, doesn't > > + * work on gcc 4.2.2 (ELDK42), but does on gcc 4.4.1 and above. > > + * The work-around is to use the (ugly) 4-pass mov/orr below. > > + * > > + * asm volatile("ldr sp, =%c0\n" : : > > + * "i"(AVP_EARLY_BOOT_STACK_LIMIT)); > > + */ > > + > > + asm volatile("mov sp, %0" > > + : : "i"(AVP_EARLY_BOOT_STACK_LIMIT & 0xFF)); > > + asm volatile("orr sp, %0" > > + : : "i"(AVP_EARLY_BOOT_STACK_LIMIT & 0xFF00)); > > + asm volatile("orr sp, %0" > > + : : "i"(AVP_EARLY_BOOT_STACK_LIMIT & 0xFF0000)); > > + asm volatile("orr sp, %0" > > + : : "i"(AVP_EARLY_BOOT_STACK_LIMIT & 0xFF000000)); > > > > start_cpu((u32)_start); > > halt_avp(); > > I think you said you'll send an updated patch. Yep. Needed to test w/different compilers first. Posted V2.
Tom -- nvpublic _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
