From ff493e081fd5fda330e478a49612080484099add Mon Sep 17 00:00:00 2001
From: Thom Johansen <thomj@rockbox.org>
Date: Wed, 22 Feb 2006 19:03:20 +0000
Subject: Commit correct file this time.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8786 a1c6a512-1295-4272-9138-f99709370657
---
 firmware/common/memset_a.S | 81 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)

(limited to 'firmware/common/memset_a.S')

diff --git a/firmware/common/memset_a.S b/firmware/common/memset_a.S
index 9403e8d68e..b6a9ca8f71 100644
--- a/firmware/common/memset_a.S
+++ b/firmware/common/memset_a.S
@@ -18,7 +18,11 @@
  ****************************************************************************/
 #include "config.h"
 
+#ifdef CPU_ARM
+    .section    .icode,"ax",%progbits
+#elif
     .section    .icode,"ax",@progbits
+#endif
 
     .align      2
 #if CONFIG_CPU == SH7034        
@@ -234,4 +238,81 @@ memset:
 
 .end:
     .size   memset,.end-memset
+
+#elif defined(CPU_ARM)
+
+/*  The following code is taken from the Linux kernel version 2.6.15.3
+ *  linux/arch/arm/lib/memset.S
+ *
+ *  Copyright (C) 1995-2000 Russell King
+ */
+
+@       .word   0
+1:      subs    r2, r2, #4              @ 1 do we have enough
+        blt     5f                      @ 1 bytes to align with?
+        cmp     r3, #2                  @ 1
+        strltb  r1, [r0], #1            @ 1
+        strleb  r1, [r0], #1            @ 1
+        strb    r1, [r0], #1            @ 1
+        add     r2, r2, r3              @ 1 (r2 = r2 - (4 - r3))
+/*
+ * The pointer is now aligned and the length is adjusted.  Try doing the
+ * memzero again.
+ */
+
+        .global     memset
+        .type       memset,%function
+memset:
+        ands    r3, r0, #3              @ 1 unaligned?
+        bne     1b                      @ 1
+/*
+ * we know that the pointer in r0 is aligned to a word boundary.
+ */
+        orr     r1, r1, r1, lsl #8
+        orr     r1, r1, r1, lsl #16
+        mov     r3, r1
+        cmp     r2, #16
+        blt     4f
+/*
+ * We need an extra register for this loop - save the return address and
+ * use the LR
+ */
+        str     lr, [sp, #-4]!
+        mov     ip, r1
+        mov     lr, r1
+
+2:      subs    r2, r2, #64
+        stmgeia r0!, {r1, r3, ip, lr}   @ 64 bytes at a time.
+        stmgeia r0!, {r1, r3, ip, lr}
+        stmgeia r0!, {r1, r3, ip, lr}
+        stmgeia r0!, {r1, r3, ip, lr}
+        bgt     2b
+        ldmeqfd sp!, {pc}               @ Now <64 bytes to go.
+/*
+ * No need to correct the count; we're only testing bits from now on
+ */
+        tst     r2, #32
+        stmneia r0!, {r1, r3, ip, lr}
+        stmneia r0!, {r1, r3, ip, lr}
+        tst     r2, #16
+        stmneia r0!, {r1, r3, ip, lr}
+        ldr     lr, [sp], #4
+
+4:      tst     r2, #8
+        stmneia r0!, {r1, r3}
+        tst     r2, #4
+        strne   r1, [r0], #4
+/*
+ * When we get here, we've got less than 4 bytes to zero.  We
+ * may have an unaligned pointer as well.
+ */
+5:      tst     r2, #2
+        strneb  r1, [r0], #1
+        strneb  r1, [r0], #1
+        tst     r2, #1
+        strneb  r1, [r0], #1
+        mov     pc, lr
+end:
+        .size   memset,.end-memset
 #endif
+
-- 
cgit