| Message ID | 20130207050434.GA7697@S2101-09.ap.freescale.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 02/06/2013 10:04 PM, Shawn Guo wrote: > On Wed, Feb 06, 2013 at 12:04:19PM -0700, Stephen Warren wrote: >> On 02/06/2013 02:32 AM, Russell King - ARM Linux wrote: >>> On Mon, Feb 04, 2013 at 04:01:33PM +0000, Russell King - ARM Linux wrote: >>>> On Fri, Jan 18, 2013 at 10:45:20AM +0800, Shawn Guo wrote: >>>>> Instead of giving zero support of uncompress debug for multiplatform >>>>> build, the patch turns uncompress debug into one part of DEBUG_LL >>>>> support. When DEBUG_LL is turned on for a particular platform, >>>>> uncompress debug works too for that platform. >>>>> >>>>> It reuses the platform DEBUG_LL macros by creating a simple >>>>> arch/arm/boot/compressed/debug.S with CONFIG_DEBUG_LL_INCLUDE >>>>> included there, and implements a generic putc() using those macros. >>>> >>>> Ok, I've applied this on the previso that _no one_ in future whinges if >>>> the debug infrastructure doesn't quite meet their expectation. The >>>> debug infrastructure remains first and foremost that: a simple debug >>>> infrastructure suitable for use in the early assembly and the like. >>>> >>>> That is its primary concern and trumps any requirements from consoles, >>>> early printk, decompressor output, and the like. >>> >>> ... and now I've dropped the two patches because it causes build failures >>> for all OMAP and PXA platforms. >> >> It also breaks tegra_defconfig. For reference, the (or perhaps just a) >> reason here is that arch/arm/include/debug/tegra.S references symbol >> tegra_uart_config, which is declared in arch/arm/mach-tegra/common.c, >> which isn't part of the decompressor build. Tegra's uncompress.h doesn't >> touch this symbol, hence avoids this problem. >> > Thanks for the info, Stephen. > > From what I see, the patch breaks omap, pxa and tegra build by > different causes. ... >> Perhaps the patch can be re-cast to only affect multi-platform kernels, >> and leave unconverted platforms using uncompress.h (at least, I assume >> that must be the problem). > > Indeed. The arch/arm/boot/compressed/debug.S shouldn't be part of > traditional build but only multiplatform. Let's force that with the > change below. > > 8<--- > diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile > index c9865f6..13bdd10 100644 > --- a/arch/arm/boot/compressed/Makefile > +++ b/arch/arm/boot/compressed/Makefile > @@ -24,9 +24,11 @@ endif > AFLAGS_head.o += -DTEXT_OFFSET=$(TEXT_OFFSET) > HEAD = head.o > OBJS += misc.o decompress.o > +ifeq ($(CONFIG_ARCH_MULTIPLATFORM),y) > ifeq ($(CONFIG_DEBUG_LL),y) > OBJS += debug.o > endif > +endif > FONTC = $(srctree)/drivers/video/console/font_acorn_8x8.c > > # string library code (-Os is enforced to keep it much smaller) > --->8 Yes, that patch fixes the build problem for me, and all decompressor output and earlyprintk works. Thanks.
On Thu, Feb 07, 2013 at 01:04:36PM +0800, Shawn Guo wrote: > === omap === > > AS arch/arm/boot/compressed/debug.o > LD arch/arm/boot/compressed/vmlinux > `.data' referenced in section `.text' of arch/arm/boot/compressed/debug.o: defined in discarded section `.data' of arch/arm/boot/compressed/debug.o > make[3]: *** [arch/arm/boot/compressed/vmlinux] Error 1 > > The following change moving the variables out of stack section seems > fixing the failure, but I'm not quite sure if it works. > > 8<--- > diff --git a/arch/arm/mach-omap2/include/mach/debug-macro.S b/arch/arm/mach-omap2/include/mach/debug > index cfaed13..7b2877e 100644 > --- a/arch/arm/mach-omap2/include/mach/debug-macro.S > +++ b/arch/arm/mach-omap2/include/mach/debug-macro.S > @@ -17,11 +17,9 @@ > > #define UART_OFFSET(addr) ((addr) & 0x00ffffff) > > - .pushsection .data > omap_uart_phys: .word 0 > omap_uart_virt: .word 0 > omap_uart_lsr: .word 0 > - .popsection No, this won't work, because now these variables are located in the text section which may not be writable. I don't know what the answer is to this, but as things stand it's not something that can go into v3.8 until these problems are addressed (because if it does it _will_ cause regressions.) We're basically on the last day of -rc6, so I think it's all too late to try and get this sorted for this merge window.
=== omap === AS arch/arm/boot/compressed/debug.o LD arch/arm/boot/compressed/vmlinux `.data' referenced in section `.text' of arch/arm/boot/compressed/debug.o: defined in discarded section `.data' of arch/arm/boot/compressed/debug.o make[3]: *** [arch/arm/boot/compressed/vmlinux] Error 1 The following change moving the variables out of stack section seems fixing the failure, but I'm not quite sure if it works. 8<--- diff --git a/arch/arm/mach-omap2/include/mach/debug-macro.S b/arch/arm/mach-omap2/include/mach/debug index cfaed13..7b2877e 100644 --- a/arch/arm/mach-omap2/include/mach/debug-macro.S +++ b/arch/arm/mach-omap2/include/mach/debug-macro.S @@ -17,11 +17,9 @@ #define UART_OFFSET(addr) ((addr) & 0x00ffffff) - .pushsection .data omap_uart_phys: .word 0 omap_uart_virt: .word 0 omap_uart_lsr: .word 0 - .popsection /* * Note that this code won't work if the bootloader passes --->8 === pxa/mmp === AS arch/arm/boot/compressed/debug.o arch/arm/boot/compressed/debug.S: Assembler messages: arch/arm/boot/compressed/debug.S:8: Error: garbage following instruction -- `ldr r2,=IOMEM(0xfe000000)' make[3]: *** [arch/arm/boot/compressed/debug.o] Error 1 This is fairly easy to fix with the following change. 8<--- diff --git a/arch/arm/boot/compressed/debug.S b/arch/arm/boot/compressed/debug.S index bdb0e25..6e8382d 100644 --- a/arch/arm/boot/compressed/debug.S +++ b/arch/arm/boot/compressed/debug.S @@ -1,4 +1,5 @@ #include <linux/linkage.h> +#include <asm/assembler.h> #include CONFIG_DEBUG_LL_INCLUDE --->8 === tegra === LD arch/arm/boot/compressed/vmlinux arch/arm/boot/compressed/debug.o: In function `putc': arch/arm/boot/compressed/debug.S:7: undefined reference to `tegra_uart_config' make[3]: *** [arch/arm/boot/compressed/vmlinux] Error 1 You have explained the cause clearly. > I'd guess OMAP is broken for similar reasons, since when I created the > tegra_uart_config symbol I was inspired by the OMAP DEBUG_LL code. > > Perhaps the patch can be re-cast to only affect multi-platform kernels, > and leave unconverted platforms using uncompress.h (at least, I assume > that must be the problem). Indeed. The arch/arm/boot/compressed/debug.S shouldn't be part of traditional build but only multiplatform. Let's force that with the change below. 8<--- diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index c9865f6..13bdd10 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -24,9 +24,11 @@ endif AFLAGS_head.o += -DTEXT_OFFSET=$(TEXT_OFFSET) HEAD = head.o OBJS += misc.o decompress.o +ifeq ($(CONFIG_ARCH_MULTIPLATFORM),y) ifeq ($(CONFIG_DEBUG_LL),y) OBJS += debug.o endif +endif FONTC = $(srctree)/drivers/video/console/font_acorn_8x8.c # string library code (-Os is enforced to keep it much smaller)