[U-Boot] [PATCH] armv7: do not relocate _start twice

[Vincent Stehlé]

The _start symbol is already relocated, so do not add the relocation the second
time in c_runtime_cpu_setup.

This fixes e.g. the abort exception handling path, which ended in double fault
due to bad address in VBAR.

Signed-off-by: Vincent Stehlé <v-stehle at ti.com>
Reported-by: Lubomir Popov <lpopov at mm-sol.com>
---


Hello,

Here is a fix for a bug reported by Lubomir. He noticed that exceptions were
not handled correctly anymore. This can be seen with e.g. the 'dhcp' command on
some OMAP platforms.

Looking at the code, I would says the fix applies to all armv7 platforms except
Tegra but I did only test on OMAP5. On this platform at least the abort is now
handled:

  OMAP5430 EVM # dhcp
  data abort

      MAYBE you should read doc/README.arm-unaligned-accesses

  pc : [<fef9bd78>]          lr : [<fefa1790>]
  sp : feef9dc4  ip : fefed0f8     fp : 00000000
  r10: 00000001  r9 : 00000001     r8 : feef9f48
  r7 : feef9fe0  r6 : 00000000     r5 : 00000000  r4 : 00000014
  r3 : 00000000  r2 : 00000002     r1 : 00000014  r0 : fefed0f4
  Flags: Nzcv  IRQs off  FIQs off  Mode SVC_32
  Resetting CPU ...

  resetting ...

It would be appreciated if folks could verify on other ARMv7 platforms, when
running from flash for example (where relocation may differ?)


 arch/arm/cpu/armv7/start.S |    1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index 6b59529d..d06b35f 100644
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -254,7 +254,6 @@ ENTRY(c_runtime_cpu_setup)
 #if !defined(CONFIG_TEGRA)
 	/* Set vector address in CP15 VBAR register */
 	ldr     r0, =_start
-	add     r0, r0, r9
 	mcr     p15, 0, r0, c12, c0, 0  @Set VBAR
 #endif /* !Tegra */
 
-- 
1.7.10.4