From a1f49718aee378fa075303c86106309091d56b80 Mon Sep 17 00:00:00 2001
From: Christian Cunningham <cc@localhost>
Date: Mon, 31 Jan 2022 19:05:50 -0700
Subject: Break exceptions off to own files

---
 src/exceptions/undefined.S | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 src/exceptions/undefined.S

(limited to 'src/exceptions/undefined.S')

diff --git a/src/exceptions/undefined.S b/src/exceptions/undefined.S
new file mode 100644
index 0000000..b8eab29
--- /dev/null
+++ b/src/exceptions/undefined.S
@@ -0,0 +1,34 @@
+.section ".text.exceptions"
+.globl undefined
+undefined:
+	cpsid aif
+	stmfd sp!, {r0-r12,lr}
+	ldr r4, [lr, #-4]
+	mov r0, #0
+	mov r1, #17
+	ldr r2, =undefined_msg
+	bl draw_string
+	mov r0, #18
+	mov r1, #17
+	mov r2, r4
+	bl draw_hex32
+	mov r0, #27
+	mov r1, #17
+	ldr r2, =undefined_at
+	bl draw_string
+	// Output lr
+	mov r1, #0x1000
+	ldr r0, [r1, #-4]
+	sub r2, r0, #4
+	mov r0, #31
+	mov r1, #17
+	bl draw_hex32
+	// Skip instruction for now
+	// In future, 
+	//  ldmfd sp!, {r0-r12,lr} // Note the lack of ^ since subs will handle it
+	//  subs pc, lr, #4
+	ldmfd sp!, {r0-r12,pc}^
+
+.section .data
+undefined_msg:	.asciz "Undefined Handler"
+undefined_at:	.asciz "@ 0x"
-- 
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