X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=KernelLand%2FKernel%2Farch%2Farmv7%2Fstart.S;h=1fe0fd866fb3551fd6a1bbcd129e115fb67aca7b;hb=85362e8a4c919b58cd261345d29f26bae4ad75e2;hp=113c8a43cdcddcb10bf009b166988304fbdec283;hpb=51ab5f489bc356940c95cc936fd0508e8f07ea97;p=tpg%2Facess2.git

diff --git a/KernelLand/Kernel/arch/armv7/start.S b/KernelLand/Kernel/arch/armv7/start.S
index 113c8a43..1fe0fd86 100644
--- a/KernelLand/Kernel/arch/armv7/start.S
+++ b/KernelLand/Kernel/arch/armv7/start.S
@@ -16,8 +16,17 @@ ivt_unused:	b .     	@ 0x14 Not Used
 ivt_irq:	b IRQHandler	@ 0x18 IRQ
 ivt_fiq:	b .     	@ 0x1C FIQ (Fast interrupt)
 
+init_lock:	.long 0
+
+.extern SHORTLOCK
 .globl _start
 _start:
+	ldr r1, =init_lock
+	mov r0, #1
+	swp r0, r0, [r1]
+	tst r0,r0
+	bne .smp_halt
+	
 	ldr r2, =UART0_PADDR
 	mov r1, #'A'
 	str r1, [r2]	
@@ -67,13 +76,17 @@ _start:
 	@
 	mrc p15, 0, r0, c0, c1, 1
 	and r0, #0xF0
+	beq .no_sec_ext
 	@ - Present
-	ldrne r0,=KERNEL_BASE
-	mcrne p15, 0, r0, c12, c0, 0	@ Set the VBAR (brings exceptions into high memory)
+	ldr r0,=KERNEL_BASE
+	mcr p15, 0, r0, c12, c0, 0	@ Set the VBAR (brings exceptions into high memory)
+	b .exceptions_vectored
+.no_sec_ext:
 	@ - Absent
-	mrceq p15, 0, r0, c1, c0, 0	@ Set SCTLR.V
-	orreq r0, #0x2000
-	mcreq p15, 0, r0, c1, c0, 0
+	mrc p15, 0, r0, c1, c0, 0	@ Set SCTLR.V
+	orr r0, #0x2000
+	mcr p15, 0, r0, c1, c0, 0
+.exceptions_vectored:
 
 	mov r1, #'-'
 	str r1, [r2]	
@@ -112,6 +125,8 @@ _start:
 	ldr r0, =kmain
 	mov pc, r0
 1:	b 1b	@ Infinite loop
+.smp_halt:
+1:	b 1b
 
 .comm irqstack, 0x1000	@ ; 4KiB Stack
 .comm abortstack, 0x1000	@ ; 4KiB Stack
@@ -194,12 +209,21 @@ DataAbort:
 @	cpsid ifa, #19
 	PUSH_GPRS
 
+	@ Get the user's LR value (and push to stack)
+	cps #31	@ Go to system mode
+	mov r1, lr
+	cps #19	@ Go to supervisor
+	mov r0, lr
+	cps #23	@ back to exception
+	push {r0,r1}
+	
 	mov r3, #0	@ not a prefetch abort
 	mrc p15, 0, r2, c5, c0, 0	@ Read DFSR (Data Fault Status Register) to R2
 	mrc p15, 0, r1, c6, c0, 0	@ Read DFAR (Data Fault Address Register) into R1
 	mov r0, lr	@ PC
 	ldr r4, =MM_PageFault
 	blx r4
+	add sp, #8	@ Undo push of the user/system LR
 
 	POP_GPRS
 	rfeia sp!	@ Pop state (actually RFEFD)
@@ -211,17 +235,24 @@ PrefetchAbort:
 @	cpsid ifa, #19
 	PUSH_GPRS
 
-	ldr r0, =csAbort_Tag
-	ldr r1, =csPrefetchAbort_Fmt
-#	mov r2, lr
-	mrc p15, 0, r2, c6, c0, 2	@ Read IFAR (Instruction Fault Address Register) into R3
-	mrc p15, 0, r3, c5, c0, 1	@ Read IFSR (Instruction Fault Status Register) into R3
-	ldr r5, =Log_Error
-	blx r5
 
-.loop:
-	wfi
-	b .loop
+	@ Get the user's LR value (and push to stack)
+	cps #31	@ Go to system mode
+	mov r0, lr
+	cps #23	@ back to supervisor
+	push {r0}
+	
+	mrc p15, 0, r2, c5, c0, 1	@ Read IFSR (Instruction Fault Status Register) into R3
+	mrc p15, 0, r1, c6, c0, 2	@ Read IFAR (Instruction Fault Address Register) into R3
+	mov r0, r1
+	mov r3, #1	@ IS a prefetch abort
+	ldr r4, =MM_PageFault
+	blx r4
+	add sp, #4	@ Undo push of the user LR
+
+	POP_GPRS
+	rfeia sp!	@ Pop state (actually RFEFD)
+
 .globl Undef_Handler
 Undef_Handler:
 	wfi
@@ -238,7 +269,7 @@ csIRQ_Fmt:
 csDataAbort_Fmt:
 	.asciz "Data Abort - %p accessed %p, DFSR=%x Unk:%x Unk:%x"
 csPrefetchAbort_Fmt:
-	.asciz "Prefetch Abort at %p, IFSR=%x"
+	.asciz "Prefetch Abort at %p, IFSR=%x, UserLR:0x%x"
 csSyscallPrintRetAddr:
 	.asciz "Syscall ret to %p"