On Mon, Jan 14, 2013 at 05:13:09PM -0500, Nicolas Pitre wrote: > On Fri, 11 Jan 2013, Sascha Hauer wrote: > > > On Thu, Jan 03, 2013 at 04:55:00PM +0100, Tomasz Figa wrote: > > > Hi, > > > > > > I'm observing strange behavior when booting 3.8-rc1 and -rc2 with appended > > > DTB. The kernel hangs very early when the DTB is bigger than some > > > threshold somewhere around 24 KiB. With fullest possible low level UART > > > debugging (and printk patched to use printascii) I'm receiving following > > > output: > > > > > > Uncompressing Linux... done, booting the kernel. > > > Booting Linux on physical CPU 0xa00 > > > Linux version 3.8.0-rc1-00073-gdf6efca-dirty (t.figa@amdc1227) (gcc > > > version 4.5.2 (Gentoo 4.5.2 p1.2, pie-0.4.5) ) #2 SMP PREEMPT Thu Jan 3 > > > 15:37:35 CET 2013 > > > CPU: ARMv7 Processor [413fc090] revision 0 (ARMv7), cr=10c53c7d > > > CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache > > > > > > I tested on two Exynos-based boards (exynos4210-trats and one internal > > > exynos4412-based board) and same happens on both. > > > > > > Do you have any ideas? > > > > Another thing besides the things already mentioned is that the dtb may > > not cross a 1MiB boundary. The Kernel uses a single 1Mib section > > (aligned to 1Mib) to initially map the dtb. Once you cross that boundary > > parts of the dtb won't be accessible for the Kernel anymore. > > Crap. You're right. This patch should fix this issue. Just successfully tested with a devicetree explicitly located just before a 1MiB boundary, so: Tested-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> Sascha > > @Tomasz: please could you confirm this fixes your initial problem? > > > diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S > index 4eee351f46..61fcb18c7e 100644 > --- a/arch/arm/kernel/head.S > +++ b/arch/arm/kernel/head.S > @@ -246,6 +246,7 @@ __create_page_tables: > > /* > * Then map boot params address in r2 if specified. > + * We map 2 sections in case the ATAGs/DTB crosses a section boundary. > */ > mov r0, r2, lsr #SECTION_SHIFT > movs r0, r0, lsl #SECTION_SHIFT > @@ -253,6 +254,8 @@ __create_page_tables: > addne r3, r3, #PAGE_OFFSET > addne r3, r4, r3, lsr #(SECTION_SHIFT - PMD_ORDER) > orrne r6, r7, r0 > + strne r6, [r3], #1 << PMD_ORDER > + addne r6, r6, #1 << SECTION_SHIFT > strne r6, [r3] > > #ifdef CONFIG_DEBUG_LL > -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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