[PATCH 10/30] ARM: head.S: use PC relative insn sequence to calculate PHYS_OFFSET
Ard Biesheuvel
ard.biesheuvel at linaro.org
Mon Aug 14 05:53:51 PDT 2017
Replace the open coded arithmetic with a simple adr_l/sub pair. This
ensures these quantities are invariant under runtime relocation.
Cc: Russell King <linux at armlinux.org.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
---
arch/arm/kernel/head.S | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index f607e290ef4b..62c961849035 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -106,10 +106,8 @@ ENTRY(stext)
#endif
#ifndef CONFIG_XIP_KERNEL
- adr r3, 2f
- ldmia r3, {r4, r8}
- sub r4, r3, r4 @ (PHYS_OFFSET - PAGE_OFFSET)
- add r8, r8, r4 @ PHYS_OFFSET
+ adr_l r8, _text @ __pa(_text)
+ sub r8, r8, #TEXT_OFFSET @ PHYS_OFFSET
#else
ldr r8, =PLAT_PHYS_OFFSET @ always constant in this case
#endif
@@ -161,10 +159,6 @@ ENTRY(stext)
1: b __enable_mmu
ENDPROC(stext)
.ltorg
-#ifndef CONFIG_XIP_KERNEL
-2: .long .
- .long PAGE_OFFSET
-#endif
/*
* Setup the initial page tables. We only setup the barest
--
2.11.0
More information about the linux-arm-kernel
mailing list