| Message ID | 1374661682-9349-5-git-send-email-ben.dooks@codethink.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jul 24, 2013 at 11:27:52AM +0100, Ben Dooks wrote: > If we are booting in LE and compiled for BE8, then add code to > set the state to bE8. Since the instruction stream is always LE, > we do not need to do anything special to the instruction. > > Also ensure that the secondary processors are started in the same mode. > > Note, we do add about 20 bytes to the kernel image, but it seems easier > to do this than adding another configuration to change. > > Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> > --- > arch/arm/boot/compressed/head.S | 1 + > arch/arm/kernel/head.S | 4 ++++ > arch/arm/kernel/sleep.S | 1 + > 3 files changed, 6 insertions(+) > > diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S > index 4eb8364..4d83bfd 100644 > --- a/arch/arm/boot/compressed/head.S > +++ b/arch/arm/boot/compressed/head.S > @@ -135,6 +135,7 @@ start: > .word _edata @ zImage end address > THUMB( .thumb ) > 1: > + ARM_BE8( setend be ) @ go BE8 if LE, no-op if BE8 I find the comment here slightly confusing as it makes it sound like the macro expands to nothing if we're BE8 (which is clearly not the case). > mrs r9, cpsr > #ifdef CONFIG_ARM_VIRT_EXT > bl __hyp_stub_install @ get into SVC mode, reversibly > diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S > index e40c0b3b..706c441 100644 > --- a/arch/arm/kernel/head.S > +++ b/arch/arm/kernel/head.S > @@ -77,6 +77,7 @@ > > __HEAD > ENTRY(stext) > + ARM_BE8(setend be ) @ ensure we are in BE8 mode Alignment issue here -- please try to align the instruction with the instructions below (it's awkward to read with all the brackets). > > THUMB( adr r9, BSYM(1f) ) @ Kernel is always entered in ARM. > THUMB( bx r9 ) @ If this is a Thumb-2 kernel, > @@ -351,6 +352,9 @@ ENTRY(secondary_startup) > * the processor type - there is no need to check the machine type > * as it has already been validated by the primary processor. > */ > + > + ARM_BE8(setend be) @ if system starts LE, go BE8 > + > #ifdef CONFIG_ARM_VIRT_EXT > bl __hyp_stub_install_secondary > #endif > diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S > index 987dcf3..954c28a 100644 > --- a/arch/arm/kernel/sleep.S > +++ b/arch/arm/kernel/sleep.S > @@ -81,6 +81,7 @@ ENDPROC(cpu_resume_after_mmu) > .data > .align > ENTRY(cpu_resume) > +ARM_BE8(setend be) @ ensure we are in BE mode Any reason to have three different comments for the same thing? I think you probably just need to comment the one in head.S. Will
On 24/07/13 15:41, Will Deacon wrote: > On Wed, Jul 24, 2013 at 11:27:52AM +0100, Ben Dooks wrote: >> If we are booting in LE and compiled for BE8, then add code to >> set the state to bE8. Since the instruction stream is always LE, >> we do not need to do anything special to the instruction. >> >> Also ensure that the secondary processors are started in the same mode. >> >> Note, we do add about 20 bytes to the kernel image, but it seems easier >> to do this than adding another configuration to change. >> >> Signed-off-by: Ben Dooks<ben.dooks@codethink.co.uk> >> --- >> arch/arm/boot/compressed/head.S | 1 + >> arch/arm/kernel/head.S | 4 ++++ >> arch/arm/kernel/sleep.S | 1 + >> 3 files changed, 6 insertions(+) >> >> diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S >> index 4eb8364..4d83bfd 100644 >> --- a/arch/arm/boot/compressed/head.S >> +++ b/arch/arm/boot/compressed/head.S >> @@ -135,6 +135,7 @@ start: >> .word _edata @ zImage end address >> THUMB( .thumb ) >> 1: >> + ARM_BE8( setend be ) @ go BE8 if LE, no-op if BE8 > > I find the comment here slightly confusing as it makes it sound like the > macro expands to nothing if we're BE8 (which is clearly not the case). I've changed it to "go BE8 if compiled for BE8" >> mrs r9, cpsr >> #ifdef CONFIG_ARM_VIRT_EXT >> bl __hyp_stub_install @ get into SVC mode, reversibly >> diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S >> index e40c0b3b..706c441 100644 >> --- a/arch/arm/kernel/head.S >> +++ b/arch/arm/kernel/head.S >> @@ -77,6 +77,7 @@ >> >> __HEAD >> ENTRY(stext) >> + ARM_BE8(setend be ) @ ensure we are in BE8 mode > > Alignment issue here -- please try to align the instruction with the > instructions below (it's awkward to read with all the brackets). If I move it one to the left, then it gets coloured blue by my editor, as it is the first thing on the line like the ENTRY() macro. >> >> THUMB( adr r9, BSYM(1f) ) @ Kernel is always entered in ARM. >> THUMB( bx r9 ) @ If this is a Thumb-2 kernel, >> @@ -351,6 +352,9 @@ ENTRY(secondary_startup) >> * the processor type - there is no need to check the machine type >> * as it has already been validated by the primary processor. >> */ >> + >> + ARM_BE8(setend be) @ if system starts LE, go BE8 >> + >> #ifdef CONFIG_ARM_VIRT_EXT >> bl __hyp_stub_install_secondary >> #endif >> diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S >> index 987dcf3..954c28a 100644 >> --- a/arch/arm/kernel/sleep.S >> +++ b/arch/arm/kernel/sleep.S >> @@ -81,6 +81,7 @@ ENDPROC(cpu_resume_after_mmu) >> .data >> .align >> ENTRY(cpu_resume) >> +ARM_BE8(setend be) @ ensure we are in BE mode > > Any reason to have three different comments for the same thing? I think you > probably just need to comment the one in head.S. I've changed the comments to match in.
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 4eb8364..4d83bfd 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -135,6 +135,7 @@ start: .word _edata @ zImage end address THUMB( .thumb ) 1: + ARM_BE8( setend be ) @ go BE8 if LE, no-op if BE8 mrs r9, cpsr #ifdef CONFIG_ARM_VIRT_EXT bl __hyp_stub_install @ get into SVC mode, reversibly diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index e40c0b3b..706c441 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -77,6 +77,7 @@ __HEAD ENTRY(stext) + ARM_BE8(setend be ) @ ensure we are in BE8 mode THUMB( adr r9, BSYM(1f) ) @ Kernel is always entered in ARM. THUMB( bx r9 ) @ If this is a Thumb-2 kernel, @@ -351,6 +352,9 @@ ENTRY(secondary_startup) * the processor type - there is no need to check the machine type * as it has already been validated by the primary processor. */ + + ARM_BE8(setend be) @ if system starts LE, go BE8 + #ifdef CONFIG_ARM_VIRT_EXT bl __hyp_stub_install_secondary #endif diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S index 987dcf3..954c28a 100644 --- a/arch/arm/kernel/sleep.S +++ b/arch/arm/kernel/sleep.S @@ -81,6 +81,7 @@ ENDPROC(cpu_resume_after_mmu) .data .align ENTRY(cpu_resume) +ARM_BE8(setend be) @ ensure we are in BE mode #ifdef CONFIG_SMP adr r0, sleep_save_sp ALT_SMP(mrc p15, 0, r1, c0, c0, 5)
If we are booting in LE and compiled for BE8, then add code to set the state to bE8. Since the instruction stream is always LE, we do not need to do anything special to the instruction. Also ensure that the secondary processors are started in the same mode. Note, we do add about 20 bytes to the kernel image, but it seems easier to do this than adding another configuration to change. Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> --- arch/arm/boot/compressed/head.S | 1 + arch/arm/kernel/head.S | 4 ++++ arch/arm/kernel/sleep.S | 1 + 3 files changed, 6 insertions(+)