parisc: Skip HPMC during bootup
We may trigger HPMCs (= trap #1) while probing various I/O addresses for
devices. If suc a HPMC is reported by qemu, simply ignore it and return
to the next address behind the caller.
Signed-off-by: Helge Deller <deller@gmx.de>
diff --git a/src/parisc/head.S b/src/parisc/head.S
index c5da942..4f2b5b5 100644
--- a/src/parisc/head.S
+++ b/src/parisc/head.S
@@ -441,17 +441,43 @@
.endr
END(smp_ivt)
+/*******************************************************
+ Fault detection & reporting Interrupt vector table (IVT)
+ *******************************************************/
+
+/* fault happened at bootup. Return to instruction after fault. */
+ENTRY(fault_return_to_caller)
+ mfctl %cr18,TEMP
+ ldo 4(TEMP),TEMP
+ mtctl TEMP,%cr18 /* IIAOQ head */
+ ldo 4(TEMP),TEMP
+ mtctl TEMP,%cr18 /* IIAOQ tail */
+ rfi
+ nop
+END(fault_return_to_caller)
+
+/* call firmware_fault_handler in parisc.c and halt. */
+ENTRY(fault_call_firmware)
+ load32_firmware firmware_fault_handler,TEMP
+ loadgp
+ bv,n 0(TEMP)
+END(fault_call_firmware)
+
.align 32
ENTRY(firmware_default_ivt) /* to detect crashes */
.set loop,0
.import firmware_fault_handler,code
.rept 32
- .align 32
- load32_firmware firmware_fault_handler,%arg0
- loadgp
- bv 0(%arg0)
- ldi loop,%arg0
+ /* Make sure to use shadow registers only! */
+ /* While booting up we check if various devices are available.
+ Allow such checks and do not raise an HPMC. */
+ ldi loop,TEMP /* trap# into TEMP */
+ cmpib,= 1,TEMP,fault_return_to_caller
+ nop
+ b fault_call_firmware
+ ldi loop,%arg0 /* trap# into arg0 */
.set loop,loop+1
+ .align 32
.endr
END(smp_ivt)
