move to new directory

git-svn-id: https://svn.openpcd.org:2342/trunk@191 6dc7ffe9-61d6-0310-9af1-9938baff3ed1

1 files changed, 33 insertions, 0 deletions

diff --git a/firmware/lib/bitops.h b/firmware/lib/bitops.h
new file mode 100644
index 0000000..428c9a6
--- /dev/null
+++ b/firmware/lib/bitops.h
@@ -0,0 +1,33 @@
+	.macro	bitop, instr
+	and	r2, r0, #7
+	mov	r3, #1
+	mov	r3, r3, lsl r2
+	save_and_disable_irqs ip
+	ldrb	r2, [r1, r0, lsr #3]
+	\instr	r2, r2, r3
+	strb	r2, [r1, r0, lsr #3]
+	restore_irqs ip
+	mov	pc, lr
+	.endm
+
+/**
+ * testop - implement a test_and_xxx_bit operation.
+ * @instr: operational instruction
+ * @store: store instruction
+ *
+ * Note: we can trivially conditionalise the store instruction
+ * to avoid dirting the data cache.
+ */
+	.macro	testop, instr, store
+	add	r1, r1, r0, lsr #3
+	and	r3, r0, #7
+	mov	r0, #1
+	save_and_disable_irqs ip
+	ldrb	r2, [r1]
+	tst	r2, r0, lsl r3
+	\instr	r2, r2, r0, lsl r3
+	\store	r2, [r1]
+	restore_irqs ip
+	moveq	r0, #0
+	mov	pc, lr
+	.endm