diff options
Diffstat (limited to 'os/boot/pc/x16.h')
| -rw-r--r-- | os/boot/pc/x16.h | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/os/boot/pc/x16.h b/os/boot/pc/x16.h new file mode 100644 index 00000000..9c204328 --- /dev/null +++ b/os/boot/pc/x16.h @@ -0,0 +1,159 @@ +/* + * Can't write 16-bit code for 8a without getting into + * lots of bother, so define some simple commands and + * output the code directly. + * + * N.B. CALL16(x) kills DI, so don't expect it to be + * saved across calls. + */ +#define rAX 0 /* rX */ +#define rCX 1 +#define rDX 2 +#define rBX 3 +#define rSP 4 /* SP */ +#define rBP 5 /* BP */ +#define rSI 6 /* SI */ +#define rDI 7 /* DI */ + +#define rAL 0 /* rL */ +#define rCL 1 +#define rDL 2 +#define rBL 3 +#define rAH 4 /* rH */ +#define rCH 5 +#define rDH 6 +#define rBH 7 + +#define rES 0 /* rS */ +#define rCS 1 +#define rSS 2 +#define rDS 3 +#define rFS 4 +#define rGS 5 + +#define xSI 4 /* rI (index) */ +#define xDI 5 +#define xBP 6 +#define xBX 7 + +#define rCR0 0 /* rC */ +#define rCR2 2 +#define rCR3 3 +#define rCR4 4 + +#define OP(o, m, ro, rm) BYTE $o; /* op + modr/m byte */ \ + BYTE $(((m)<<6)|((ro)<<3)|(rm)) +#define OPrm(o, r, m) OP(o, 0x00, r, 0x06); /* general r <-> m */ \ + WORD $m; +#define OPrr(o, r0, r1) OP(o, 0x03, r0, r1); /* general r -> r */ + +#define LW(m, rX) OPrm(0x8B, rX, m) /* m -> rX */ +#define LXW(x, rI, r) OP(0x8B, 0x02, r, rI); /* x(rI) -> r */ \ + WORD $x +#define LBPW(x, r) OP(0x8B, 0x02, r, xBP); /* x(rBP) -> r */ \ + WORD $x +#define LB(m, rB) OPrm(0x8A, rB, m) /* m -> r[HL] */ +#define LXB(x, rI, r) OP(0x8A, 0x01, r, rI); /* x(rI) -> r */ \ + BYTE $x +#define LBPB(x, r) OP(0x8A, 0x01, r, xBP); /* x(rBP) -> r */ \ + BYTE $x +#define SW(rX, m) OPrm(0x89, rX, m) /* rX -> m */ +#define SXW(r, x, rI) OP(0x89, 0x02, r, rI); /* r -> x(rI) */ \ + WORD $x +#define SBPW(r, x) OP(0x89, 0x02, r, xBP); /* r -> x(rBP) */ \ + WORD $(x) +#define SBPWI(i, x) OP(0xC7, 0x01, 0, xBP); /* i -> x(rBP) */ \ + BYTE $(x); WORD $(i) +#define STB(rB, m) OPrm(0x88, rB, m) /* rB -> m */ +#define SXB(r, x, rI) OP(0x88, 0x01, r, rI); /* rB -> x(rI) */ \ + BYTE $x +#define SBPB(r, x) OP(0x88, 0x01, r, xBP); /* r -> x(rBP) */ \ + BYTE $x +#define SBPBI(i, x) OP(0xC6, 0x01, 0, xBP); /* i -> x(rBP) */ \ + BYTE $(x); BYTE $(i) +#define LWI(i, rX) BYTE $(0xB8+rX); /* i -> rX */ \ + WORD $i; +#define LBI(i, rB) BYTE $(0xB0+rB); /* i -> r[HL] */ \ + BYTE $i + +#define MW(r0, r1) OPrr(0x89, r0, r1) /* r0 -> r1 */ +#define MFSR(rS, rX) OPrr(0x8C, rS, rX) /* rS -> rX */ +#define MTSR(rX, rS) OPrr(0x8E, rS, rX) /* rX -> rS */ +#define MFCR(rC, rX) BYTE $0x0F; /* rC -> rX */ \ + OP(0x20, 0x03, rC, rX) +#define MTCR(rX, rC) BYTE $0x0F; /* rX -> rC */ \ + OP(0x22, 0x03, rC, rX) + +#define ADC(r0, r1) OPrr(0x11, r0, r1) /* r0 + r1 -> r1 */ +#define ADD(r0, r1) OPrr(0x01, r0, r1) /* r0 + r1 -> r1 */ +#define ADDI(i, r) OP(0x81, 0x03, 0x00, r);/* i+r -> r */ \ + WORD $i; +#define AND(r0, r1) OPrr(0x21, r0, r1) /* r0&r1 -> r1 */ +#define ANDI(i, r) OP(0x81, 0x03, 0x04, r);/* i&r -> r */ \ + WORD $i; +#define CLR(r) OPrr(0x31, r, r) /* r^r -> r */ +#define CLRB(r) OPrr(0x30, r, r) /* r^r -> r */ +#define CMP(r0, r1) OPrr(0x39, r0, r1) /* r1-r0 -> flags */ +#define CMPI(i, r) OP(0x81, 0x03, 0x07, r);/* r-i -> flags */ \ + WORD $i; +#define CMPBR(r0, r1) OPrr(0x38, r0, r1) /* r1-r0 -> flags */ +#define DEC(r) BYTE $(0x48|r) /* r-1 -> r */ +#define DIV(r) OPrr(0xF7, 0x06, r) /* rDX:rAX/r -> rAX, rDX:rAX%r -> rDX */ +#define INC(r) BYTE $(0x40|r) /* r+1 -> r */ +#define MUL(r) OPrr(0xF7, 0x04, r) /* r*rAX -> rDX:rAX */ +#define IMUL(r0, r1) BYTE $0x0F; /* r0*r1 -> r1 */ \ + OPrr(0xAF, r1, r0) /* (signed) */ +#define OR(r0, r1) OPrr(0x09, r0, r1) /* r0|r1 -> r1 */ +#define ORB(r0, r1) OPrr(0x08, r0, r1) /* r0|r1 -> r1 */ +#define ORI(i, r) OP(0x81, 0x03, 0x01, r);/* i|r -> r */ \ + WORD $i; +#define ROLI(i, r) OPrr(0xC1, 0x00, r); /* r<<>>i -> r */ \ + BYTE $i; +#define SHLI(i, r) OPrr(0xC1, 0x04, r); /* r<<i -> r */ \ + BYTE $i; +#define SHLBI(i, r) OPrr(0xC0, 0x04, r); /* r<<i -> r */ \ + BYTE $i; +#define SHRI(i, r) OPrr(0xC1, 0x05, r); /* r>>i -> r */ \ + BYTE $i; +#define SHRBI(i, r) OPrr(0xC0, 0x05, r); /* r>>i -> r */ \ + BYTE $i; +#define SUB(r0, r1) OPrr(0x29, r0, r1) /* r1-r0 -> r1 */ +#define SUBI(i, r) OP(0x81, 0x03, 0x05, r);/* r-i -> r */ \ + WORD $i; + +#define STOSW STOSL + +#define CALL16(f) LWI(f, rDI); /* &f -> rDI */ \ + BYTE $0xFF; /* (*rDI) */ \ + BYTE $0xD7; +#define FARJUMP16(s, o) BYTE $0xEA; /* jump to ptr16:16 */ \ + WORD $o; WORD $s +#define FARJUMP32(s, o) BYTE $0x66; /* jump to ptr32:16 */ \ + BYTE $0xEA; LONG $o; WORD $s +#define DELAY BYTE $0xEB; /* jmp .+2 */ \ + BYTE $0x00 +#define BIOSCALL(b) INT $b /* INT $b */ + +#define PEEKW BYTE $0x26; /* MOVW rES:[rBX], rAX */ \ + BYTE $0x8B; BYTE $0x07 +#define POKEW BYTE $0x26; /* MOVW rAX, rES:[rBX] */ \ + BYTE $0x89; BYTE $0x07 +#define OUTPORTB(p, d) LBI(d, rAL); /* d -> I/O port p */ \ + BYTE $0xE6; \ + BYTE $p; DELAY +#define PUSHA BYTE $0x60 +#define PUSHR(r) BYTE $(0x50|r) /* r -> (--rSP) */ +#define PUSHS(rS) BYTE $(0x06|((rS)<<3)) /* rS -> (--rSP) */ +#define PUSHI(i) BYTE $0x68; WORD $i; /* i -> --(rSP) */ +#define POPA BYTE $0x61 +#define POPR(r) BYTE $(0x58|r) /* (rSP++) -> r */ +#define POPS(rS) BYTE $$(0x07|((rS)<<3)) /* (rSP++) -> r */ +#define NOP BYTE $0x90 /* nop */ + +#define LGDT(gdtptr) BYTE $0x0F; /* LGDT */ \ + BYTE $0x01; BYTE $0x16; \ + WORD $gdtptr + +/* operand size switch. */ +#define OPSIZE BYTE $0x66 + |