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-rw-r--r--kernel/arch/avr32/lib/io-readsb.S49
1 files changed, 49 insertions, 0 deletions
diff --git a/kernel/arch/avr32/lib/io-readsb.S b/kernel/arch/avr32/lib/io-readsb.S
new file mode 100644
index 000000000..cb2d86945
--- /dev/null
+++ b/kernel/arch/avr32/lib/io-readsb.S
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+ .text
+.Lnot_word_aligned:
+1: ld.ub r8, r12[0]
+ sub r10, 1
+ st.b r11++, r8
+ reteq r12
+ tst r11, r9
+ brne 1b
+
+ /* fall through */
+
+ .global __raw_readsb
+ .type __raw_readsb,@function
+__raw_readsb:
+ cp.w r10, 0
+ mov r9, 3
+ reteq r12
+
+ tst r11, r9
+ brne .Lnot_word_aligned
+
+ sub r10, 4
+ brlt 2f
+
+1: ldins.b r8:t, r12[0]
+ ldins.b r8:u, r12[0]
+ ldins.b r8:l, r12[0]
+ ldins.b r8:b, r12[0]
+ st.w r11++, r8
+ sub r10, 4
+ brge 1b
+
+2: sub r10, -4
+ reteq r12
+
+3: ld.ub r8, r12[0]
+ sub r10, 1
+ st.b r11++, r8
+ brne 3b
+
+ retal r12