| Message ID | 20140721175432.GB4179@bivouac.eciton.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 21 July 2014 19:54, Leif Lindholm <leif.lindholm@linaro.org> wrote: > Reported-by: Roy Franz <roy.franz@linaro.org> > > The current code in boot/compressed/head.S executes pretty much > sequentially from "start", all the way until the end of > "dtb_check_done". However, shortly after the "not_angel" symbol, there > is a section change, in the form of a ".text" directive. > > This means any literal pools in .start end up getting inserted into > the middle of the instruction stream. > > Would something like the below (pardon the semantic silliness) be an > acceptable fix? > > diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S > index 3a8b32d..8ee05e9 100644 > --- a/arch/arm/boot/compressed/head.S > +++ b/arch/arm/boot/compressed/head.S > @@ -149,6 +149,10 @@ start: > mov r0, #0x17 @ angel_SWIreason_EnterSVC > ARM( swi 0x123456 ) @ angel_SWI_ARM > THUMB( svc 0xab ) @ angel_SWI_THUMB > + b angel The idea appears to be that code in .start sections from other platform specific object files gets put there, so it gets executed extremely early. Jumping over it kind of defeats the purpose here. Instead, adding an explicit .ltorg and jumping over /that/ should do the trick, I think, but perhaps it's better just to open code the literal pool in this case.
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 3a8b32d..8ee05e9 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -149,6 +149,10 @@ start: mov r0, #0x17 @ angel_SWIreason_EnterSVC ARM( swi 0x123456 ) @ angel_SWI_ARM THUMB( svc 0xab ) @ angel_SWI_THUMB + b angel + + .text +angel: not_angel: safe_svcmode_maskall r0 msr spsr_cxsf, r9 @ Save the CPU boot mode in @@ -163,8 +167,6 @@ not_angel: * by the linker here, but it should preserve r7, r8, and r9. */ - .text - #ifdef CONFIG_AUTO_ZRELADDR @ determine final kernel image address mov r4, pc