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- /* 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
-