| Message ID | 1328086496-31184-1-git-send-email-u.kleine-koenig@pengutronix.de |
|---|---|
| State | New |
| Headers | show |
On Wed, Feb 01, 2012 at 09:54:56AM +0100, Uwe Kleine-K??nig wrote: > This fixes a linker error when the kernel image gets bigger than approx. > 1 MiB. > > This is done analogous to the change to head.S in commit > > a75e524 (ARM: 6504/1: Thumb-2: Fix long-distance conditional branches in head.S for Thumb-2.) > > Signed-off-by: Uwe Kleine-K??nig <u.kleine-koenig@pengutronix.de> > --- > Hello, > > compared to a75e524 I didn't put the it instruction into THUMB(). I > think this is OK? If so I can follow up with a patch that removes these > THUMB()s from head.S, too. I believe it can be outside THUMB()... there are macros in <asm/unified.h> which expand to nothing if necessary. However, after the original patch, I think that it may be better to code it like this: ldreq pc, =___error_p This may end up being slightly less efficient, but on an error path that doesn't really matter. The good part is that we don't need any ARM or Thumb special-case code. Because the target address is loaded from the literal pool, it can be relocated to absolutely any address without difficulty. From my point of view, this also cleaner and more manitainable in the source code, since it uses a traditional, well- understood method of achieving the long branch. If you want to keep to your existing suggestion for consistency, I'd be happy with that too, though. > > And I wonder if it's correct that head-nommu.S doesn't check the machine > type. I don't know the answer to that -- it does sound a bit strange though. Maybe that check happens somewhere else in the nommu case? (Or maybe people just never got around to adding the check, since the kernel build and hardware tend to be very tightly coupled for nommu.) > > I don't see a need to get this in before the next merge window. > > Best regards > Uwe > > > arch/arm/kernel/head-nommu.S | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S > index d46f259..1aca35d 100644 > --- a/arch/arm/kernel/head-nommu.S > +++ b/arch/arm/kernel/head-nommu.S > @@ -51,6 +51,7 @@ ENTRY(stext) > #endif > bl __lookup_processor_type @ r5=procinfo r9=cpuid > movs r10, r5 @ invalid processor (r5=0)? > + it eq > beq __error_p @ yes, error 'p' > > adr lr, BSYM(__after_proc_init) @ return (PIC) address > -- > 1.7.8.3 >
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S index d46f259..1aca35d 100644 --- a/arch/arm/kernel/head-nommu.S +++ b/arch/arm/kernel/head-nommu.S @@ -51,6 +51,7 @@ ENTRY(stext) #endif bl __lookup_processor_type @ r5=procinfo r9=cpuid movs r10, r5 @ invalid processor (r5=0)? + it eq beq __error_p @ yes, error 'p' adr lr, BSYM(__after_proc_init) @ return (PIC) address
This fixes a linker error when the kernel image gets bigger than approx. 1 MiB. This is done analogous to the change to head.S in commit a75e524 (ARM: 6504/1: Thumb-2: Fix long-distance conditional branches in head.S for Thumb-2.) Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> --- Hello, compared to a75e524 I didn't put the it instruction into THUMB(). I think this is OK? If so I can follow up with a patch that removes these THUMB()s from head.S, too. And I wonder if it's correct that head-nommu.S doesn't check the machine type. I don't see a need to get this in before the next merge window. Best regards Uwe arch/arm/kernel/head-nommu.S | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)