armv7m: update crc/erase_check loaders for cortex-m0

[openocd.git] / contrib / loaders / checksum / armv7m_crc.s

diff --git a/contrib/loaders/checksum/armv7m_crc.s b/contrib/loaders/checksum/armv7m_crc.s
index e50db0a7bde0266319f61d065b45542c63624069..8dfc40ad5398406209caa39bbf8794ea4ad87cec 100644 (file)
--- a/contrib/loaders/checksum/armv7m_crc.s
+++ b/contrib/loaders/checksum/armv7m_crc.s
@@ -26,41 +26,46 @@
 
        .text
        .syntax unified
-       .cpu cortex-m3
+       .cpu cortex-m0
        .thumb
        .thumb_func
-       
+
        .align  2
 
 _start:
-main:  
+main:
        mov             r2, r0
-       mov             r0, #0xffffffff /* crc */
+       movs    r0, #0
+       mvns    r0, r0
+       ldr             r6, CRC32XOR
        mov             r3, r1
-       mov             r4, #0
+       movs    r4, #0
        b               ncomp
 nbyte:
        ldrb    r1, [r2, r4]
-
-       ldr             r7, CRC32XOR
-       eor             r0, r0, r1, asl #24
-       mov             r5, #0
+       lsls    r1, r1, #24
+       eors    r0, r0, r1
+       movs    r5, #0
 loop:
        cmp             r0, #0
-       mov             r6, r0, asl #1
-       add             r5, r5, #1
-       mov             r0, r6
-       it              lt
-       eorlt   r0, r6, r7
+       bge             notset
+       lsls    r0, r0, #1
+       eors    r0, r0, r6
+       b               cont
+notset:
+       lsls    r0, r0, #1
+cont:
+       adds    r5, r5, #1
        cmp             r5, #8
        bne             loop
-       
-       add             r4, r4, #1
+       adds    r4, r4, #1
 ncomp:
        cmp             r4, r3
        bne             nbyte
        bkpt    #0
 
+       .align  2
+
 CRC32XOR:      .word   0x04c11db7
 
        .end