On 1/6/26 1:53 PM, Sascha Hauer wrote: > Create position-independent exception vectors using relative branches > instead of absolute addresses. This works on ARMv7 onwards which > supports setting the address of the exception vectors. > > New .text_inplace_exceptions section contains PC-relative branches, > enabling barebox proper to start with MMU already configured using > ELF segment addresses. > > Signed-off-by: Sascha Hauer <[email protected]>
Reviewed-by: Ahmad Fatoum <[email protected]> > --- > arch/arm/cpu/exceptions_32.S | 20 ++++++++++++++++++++ > arch/arm/cpu/interrupts_32.c | 7 ++----- > arch/arm/cpu/no-mmu.c | 11 +---------- > arch/arm/include/asm/sections.h | 1 + > arch/arm/lib/pbl.lds.S | 6 +++--- > arch/arm/lib32/barebox.lds.S | 4 ++++ > 6 files changed, 31 insertions(+), 18 deletions(-) > > diff --git a/arch/arm/cpu/exceptions_32.S b/arch/arm/cpu/exceptions_32.S > index > dc3d42663cbedd37947e27d449eb4ac8c3d8c3f1..85ee4ca3fd4e5aff8e1e02aa3d7375173a923072 > 100644 > --- a/arch/arm/cpu/exceptions_32.S > +++ b/arch/arm/cpu/exceptions_32.S > @@ -155,6 +155,26 @@ ENTRY(arm_fixup_vectors) > ENDPROC(arm_fixup_vectors) > #endif > > +.section .text_inplace_exceptions > +1: b 1b /* barebox_arm_reset_vector */ > +#ifdef CONFIG_ARM_EXCEPTIONS > + b undefined_instruction /* undefined instruction */ > + b software_interrupt /* software interrupt (SWI) */ > + b prefetch_abort /* prefetch abort */ > + b data_abort /* data abort */ > +1: b 1b /* (reserved) */ > + b irq /* irq (interrupt) */ > + b fiq /* fiq (fast interrupt) */ > +#else > +1: b 1b /* undefined instruction */ > +1: b 1b /* software interrupt (SWI) */ > +1: b 1b /* prefetch abort */ > +1: b 1b /* data abort */ > +1: b 1b /* (reserved) */ > +1: b 1b /* irq (interrupt) */ > +1: b 1b /* fiq (fast interrupt) */ > +#endif > + > .section .text_exceptions > .globl extable > extable: > diff --git a/arch/arm/cpu/interrupts_32.c b/arch/arm/cpu/interrupts_32.c > index > 0b88db10fe487378fe08018701bc672f63139fc1..5dc4802fafbfdbcd54707b84835f40177e10742b > 100644 > --- a/arch/arm/cpu/interrupts_32.c > +++ b/arch/arm/cpu/interrupts_32.c > @@ -231,10 +231,8 @@ static __maybe_unused int arm_init_vectors(void) > * First try to use the vectors where they actually are, works > * on ARMv7 and later. > */ > - if (!set_vector_table((unsigned long)__exceptions_start)) { > - arm_fixup_vectors(); > + if (!set_vector_table((unsigned long)__inplace_exceptions_start)) > return 0; > - } > > /* > * Next try high vectors at 0xffff0000. > @@ -264,7 +262,6 @@ void arm_pbl_init_exceptions(void) > if (cpu_architecture() < CPU_ARCH_ARMv7) > return; > > - set_vbar((unsigned long)__exceptions_start); > - arm_fixup_vectors(); > + set_vbar((unsigned long)__inplace_exceptions_start); > } > #endif > diff --git a/arch/arm/cpu/no-mmu.c b/arch/arm/cpu/no-mmu.c > index > c4ef5d1f9d55136d606c244309dbeeb8fd988784..68246d71156c7c84b9faff452cebb37132b83573 > 100644 > --- a/arch/arm/cpu/no-mmu.c > +++ b/arch/arm/cpu/no-mmu.c > @@ -21,8 +21,6 @@ > #include <asm/sections.h> > #include <asm/cputype.h> > > -#define __exceptions_size (__exceptions_stop - __exceptions_start) > - > static bool has_vbar(void) > { > u32 mainid; > @@ -41,7 +39,6 @@ static bool has_vbar(void) > > static int nommu_v7_vectors_init(void) > { > - void *vectors; > u32 cr; > > if (cpu_architecture() < CPU_ARCH_ARMv7) > @@ -58,13 +55,7 @@ static int nommu_v7_vectors_init(void) > cr &= ~CR_V; > set_cr(cr); > > - arm_fixup_vectors(); > - > - vectors = xmemalign(PAGE_SIZE, PAGE_SIZE); > - memset(vectors, 0, PAGE_SIZE); > - memcpy(vectors, __exceptions_start, __exceptions_size); > - > - set_vbar((unsigned int)vectors); > + set_vbar((unsigned int)__inplace_exceptions_start); > > return 0; > } > diff --git a/arch/arm/include/asm/sections.h b/arch/arm/include/asm/sections.h > index > 15b1a6482a5b148284ab47de2db1c2653909da09..bf4fb7b109a7a22d9a298257af23a11b9efe6861 > 100644 > --- a/arch/arm/include/asm/sections.h > +++ b/arch/arm/include/asm/sections.h > @@ -13,6 +13,7 @@ extern char __dynsym_start[]; > extern char __dynsym_end[]; > extern char __exceptions_start[]; > extern char __exceptions_stop[]; > +extern char __inplace_exceptions_start[]; > > #endif > > diff --git a/arch/arm/lib/pbl.lds.S b/arch/arm/lib/pbl.lds.S > index > 9c51f5eb3a3d8256752a78e03fed851c84d92edb..53b21084cff2e3d916cd37485281f2f78166c37d > 100644 > --- a/arch/arm/lib/pbl.lds.S > +++ b/arch/arm/lib/pbl.lds.S > @@ -53,9 +53,9 @@ SECTIONS > *(.text_bare_init*) > __bare_init_end = .; > . = ALIGN(0x20); > - __exceptions_start = .; > - KEEP(*(.text_exceptions*)) > - __exceptions_stop = .; > + __inplace_exceptions_start = .; > + KEEP(*(.text_inplace_exceptions*)) > + __inplace_exceptions_stop = .; > *(.text*) > } > > diff --git a/arch/arm/lib32/barebox.lds.S b/arch/arm/lib32/barebox.lds.S > index > c704dd6d70f3ab157ceb67dfb14760e03f2a5d62..17e0970ba4989e5213ed38ea5ff87bdf5bfa2740 > 100644 > --- a/arch/arm/lib32/barebox.lds.S > +++ b/arch/arm/lib32/barebox.lds.S > @@ -26,6 +26,10 @@ SECTIONS > __exceptions_start = .; > KEEP(*(.text_exceptions*)) > __exceptions_stop = .; > + . = ALIGN(0x20); > + __inplace_exceptions_start = .; > + KEEP(*(.text_inplace_exceptions*)) > + __inplace_exceptions_stop = .; > *(.text*) > } > BAREBOX_BARE_INIT_SIZE > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
