arm7_9: Fix broken halfword/byte memory reads
[openocd.git] / tcl / bitsbytes.tcl
1 #----------------------------------------
2 # Purpose - Create some $BIT variables
3 # Create $K and $M variables
4 # and some bit field extraction variables.
5 # Creat helper variables ...
6 # BIT0.. BIT31
7
8 for { set x 0 } { $x < 32 } { set x [expr $x + 1]} {
9 set vn [format "BIT%d" $x]
10 global $vn
11 set $vn [expr (1 << $x)]
12 }
13
14 # Create K bytes values
15 # __1K ... to __2048K
16 for { set x 1 } { $x < 2048 } { set x [expr $x * 2]} {
17 set vn [format "__%dK" $x]
18 global $vn
19 set $vn [expr (1024 * $x)]
20 }
21
22 # Create M bytes values
23 # __1M ... to __2048K
24 for { set x 1 } { $x < 2048 } { set x [expr $x * 2]} {
25 set vn [format "__%dM" $x]
26 global $vn
27 set $vn [expr (1024 * 1024 * $x)]
28 }
29
30 proc create_mask { MSB LSB } {
31 return [expr (((1 << ($MSB - $LSB + 1))-1) << $LSB)]
32 }
33
34 # Cut Bits $MSB to $LSB out of this value.
35 # Example: % format "0x%08x" [extract_bitfield 0x12345678 27 16]
36 # Result: 0x02340000
37
38 proc extract_bitfield { VALUE MSB LSB } {
39 return [expr [create_mask $MSB $LSB] & $VALUE]
40 }
41
42
43 # Cut bits $MSB to $LSB out of this value
44 # and shift (normalize) them down to bit 0.
45 #
46 # Example: % format "0x%08x" [normalize_bitfield 0x12345678 27 16]
47 # Result: 0x00000234
48 #
49 proc normalize_bitfield { VALUE MSB LSB } {
50 return [expr [extract_bitfield $VALUE $MSB $LSB ] >> $LSB]
51 }
52
53 proc show_normalize_bitfield { VALUE MSB LSB } {
54 set m [create_mask $MSB $LSB]
55 set mr [expr $VALUE & $m]
56 set sr [expr $mr >> $LSB]
57 echo [format "((0x%08x & 0x%08x) -> 0x%08x) >> %2d => (0x%x) %5d " $VALUE $m $mr $LSB $sr $sr]
58 return $sr
59 }
60
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