When booting from ROM, early exceptions can't be handled properly. Instead of busy-looping give the developer the possibilty to examine the situation. Thus issue a SDBBP instruction to transfer control to hardware debugger if one is attached.
Signed-off-by: Daniel Schwierzeck daniel.schwierzeck@gmail.com ---
arch/mips/cpu/start.S | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-)
diff --git a/arch/mips/cpu/start.S b/arch/mips/cpu/start.S index 108d2df..6886036 100644 --- a/arch/mips/cpu/start.S +++ b/arch/mips/cpu/start.S @@ -79,30 +79,30 @@ ENTRY(_start) #endif
#if defined(CONFIG_ROM_EXCEPTION_VECTORS) + /* + * Exception vector entry points. When running from ROM, an exception + * cannot be handled. Halt execution and transfer control to debugger, + * if one is attached. + */ .org 0x200 /* TLB refill, 32 bit task */ -1: b 1b - nop + sdbbp
.org 0x280 /* XTLB refill, 64 bit task */ -1: b 1b - nop + sdbbp
.org 0x300 /* Cache error exception */ -1: b 1b - nop + sdbbp
.org 0x380 /* General exception */ -1: b 1b - nop + sdbbp
.org 0x400 /* Catch interrupt exceptions */ -1: b 1b - nop + sdbbp
.org 0x480 /* EJTAG debug exception */ @@ -222,6 +222,7 @@ reset:
move a0, zero # a0 <-- boot_flags = 0 PTR_LA t9, board_init_f + jr t9 move ra, zero