1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
/* SWI veneers:
* Written by Edward Nevill and Jonathan Roach in an idle moment between projects.
* Hacked by BDB to add flag returning
*/
/* Anonymous Error type */
struct Error { int num; char msg[4]; };
typedef struct Error Error;
/* Generic SWI interface
* swi(swino,mask,regs...)
* swino = SWI number to call as defined in h.swis, X bit set if you wish the
* X form of the SWI to be called, clear if you want the non X form.
* reg_mask = mask of in / out registers
* bits 0-9: Bit N set => Register N specified on input
* Bit N clear => Register N unspecified on input
* bits 22-31: Bit N set => Register N-22 on output stored
* in address specified in varargs list.
* ... In order, input registers followed by output registers,
* starting at r0 and going up.
* returns 0 or errorblock pointer if X-bit set
* returns r0 if X-bit clear
* swix(swino,mask,regs...)
* This behaves identically to 'swi' except that it always calls the X form.
*
* Eg:
* swi(OS_SWINumberToString, IN(R0|R1|R2), n, buf, 255);
* e = swi(XOS_SWINumberFromString, IN(R1)|OUT(R0), str, &n);
* - Error block pointer (or 0) is returned so must get returned R0
* - via argument list.
* e = swix(OS_SWINumberFromString, IN(R1)|OUT(R0), str, &n);
* - As above but uses the swix function rather that setting the X bit
* explicitly (saves one instruction on SWI call).
* e = swi(OS_File, IN(R0|R1|R2|R3)|OUT(R4), 255, name, buff, 0, &len);
* - We don't care about the load, exec or attrs so don't specify
* them in the output registers.
*/
extern Error *swix(int swino, int reg_mask, ...);
extern int swi(int swino, int reg_mask, ...);
/* Register mask macros
* The bits in the register mask are arranged as follows:
* 31 30 29 ... 22 ... 8 ... 2 1 0
* O0 O1 O2 ... O9 I9 ... I2 I1 I0 I(N) = bit set if R(N) used on entry
* O(N) = bit set if R(N) written on exit
* The bits are arranged like this to optimise the case where a SWI is being
* called with a small number of input and output registers. For example, a SWI
* call which uses R0-R5 on entry and R0-R1 on exit will have a register mask
* of 0xC000003f which can be loaded into an ARM register in one instruction
* (the compiler performs this optimisation, even when the constant wraps
* around between bits 0 and 31). Using the more obvious coding of I0-I9 in bits
* 0 - 9 and O0-O9 in bits 16-23 leads to a constant of 0x0003003f which require
* two instructions.
*/
#define IN(m) (m)
/* old, incorrect version
#define OUT(m) ((unsigned)(m&1)<<31|(m&2)<<29|(m&4)<<27|(m&8)<<25|(m&16)<<23|\
(m&32)<<21|(m&64)<<19|(m&128)<<17|(m&256)<<15|(m&512)<<13)
*/
#define OUT(m) ((unsigned)((m)&1)<<31|((m)&2)<<29|((m)&4)<<27|\
((m)&8)<<25|((m)&16)<<23|((m)&32)<<21|((m)&64)<<19|\
((m)&128)<<17|((m)&256)<<15|((m)&512)<<13|((m)&1024)<<11)
/* The register names
* Change these to use different names if you use R0 - R9 elsewhere in your program
*/
#define PSW 0x400 /* Use only in OUT, orders BEFORE others */
#define R0 0x001
#define R1 0x002
#define R2 0x004
#define R3 0x008
#define R4 0x010
#define R5 0x020
#define R6 0x040
#define R7 0x080
#define R8 0x100
#define R9 0x200
|
