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8bitworkshop/presets/astrocade-bios/bios.c

632 lines
18 KiB
C
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#define TEST
#include <string.h>
typedef unsigned char byte;
typedef signed char sbyte;
typedef unsigned short word;
typedef signed short sword;
/// HARDWARE
__sfr __at(0x00) hw_col0r; // palette 0
__sfr __at(0x01) hw_col1r;
__sfr __at(0x02) hw_col2r;
__sfr __at(0x03) hw_col3r;
__sfr __at(0x04) hw_col0l;
__sfr __at(0x05) hw_col1l;
__sfr __at(0x06) hw_col2l;
__sfr __at(0x07) hw_col3l; // palette 7
__sfr __at(0x08) hw_intst; // intercept test feedback
__sfr __at(0x09) hw_horcb; // horiz color boundary
__sfr __at(0x0a) hw_verbl; // vertical blanking line * 2
__sfr __at(0x0c) hw_magic; // magic register
__sfr __at(0x0d) hw_infbk; // interrupt feedback
__sfr __at(0x0e) hw_inmod; // interrupt enable
__sfr __at(0x0f) hw_inlin; // interrupt line
__sfr __at(0x19) hw_xpand; // expander register
__sfr __at(0x10) hw_p1ctrl; // player controls
__sfr __at(0x11) hw_p2ctrl; // player controls
__sfr __at(0x12) hw_p3ctrl; // player controls
__sfr __at(0x13) hw_p4ctrl; // player controls
#define M_SHIFT0 0x00
#define M_SHIFT1 0x01
#define M_SHIFT2 0x02
#define M_SHIFT3 0x03
#define M_XPAND 0x08
#define M_MOVE 0x00
#define M_OR 0x10
#define M_XOR 0x20
#define M_FLOP 0x40
#define M_SHIFT(x) ((x)&3)
#define XPAND_COLORS(off,on) (((off)&3) | (((on)&3)<<2))
/// GRAPHICS FUNCTIONS
#define VHEIGHT 89 // number of scanlines
#define VBWIDTH 40 // number of bytes per scanline
#define PIXWIDTH 160 // 4 pixels per byte
#define EXIT_CLIPDEST(addr) if ((((word)addr)&0xfff) >= 0xe10) return
byte __at (0x0000) vmagic[VHEIGHT][VBWIDTH];
byte __at (0x4000) vidmem[VHEIGHT][VBWIDTH];
// start @ $4FCE
volatile word MUZPC; // music PC
volatile word MUZSP; // music SP
volatile byte PVOLAB; // channels A and B volume
volatile byte PVOLMC; // channel C volume and noise mask
volatile byte VOICES; // voice smask
volatile byte CT[8]; // counter timers
volatile byte CNT;
volatile byte SEMI4S;
volatile byte OPOT[4];
volatile byte KEYSEX;
volatile byte OSW[4];
volatile word COLLST;
volatile byte DURAT; // note duration
volatile byte TMR60; // 1/60 sec timer
volatile byte TIMOUT; // blackout timer
volatile byte GTSECS; // seconds timer
volatile byte GTMINS; // minutes timer
unsigned long RANSHT; // RNG
byte NUMPLY; // # players
byte ENDSCR[3]; // end score
byte MRLOCK; // magic register lock out
byte GAMSTB; // game status
byte PRIOR; // music protect
byte SENFLG; // sentry control
byte* UMARGT; // user mask table (-64 bytes)
word* USERTB; // user routine table (-128 bytes)
// start routine @ 0x0
void bios_start() __naked {
__asm
DI ; disable interrupts
LD HL,#0x2000
LD A,(HL) ; A <- mem[0x2000]
CP #0x55 ; found sentinel byte? ($55)
JP Z,FoundSentinel ; yes, load program
#ifndef TEST
JP 0x2000 ; jump to $2000
#else
JP _main ; jump to test program
#endif
FoundSentinel:
LD SP,#0x4fce ; position stack below BIOS vars
CALL _bios_init ; misc. bios init routines
LD HL,#0x2005 ; cartridge start vector
LD A,(HL)
INC HL
LD H,(HL)
LD L,A
JP (HL) ; jump to cart start vector
.ds 0x38 - 0x1b ; eat up space until 0x38
__endasm;
}
void interrupt_0x38() __naked {
__asm
push hl
push af
push bc
push de
push ix
push iy
ld hl,#0
add hl,sp
push hl ; HL points to context block
call _SYSCALL ; syscall handler
pop hl
pop iy
pop ix
pop de
pop bc
pop af
pop hl
ret
__endasm;
}
void _predope() __naked {
__asm
.ds 0x200-0x52 ; skip to 0x200
__endasm;
}
// DOPE vector @ 0x200
void DOPE() __naked {
__asm
JP _STIMER
JP _CTIMER
.db 0x20, 8, 8, 1, 7 ; Font descriptor (big font)
.dw _BIGFONT
.db 0xa0, 4, 6, 1, 5 ; Font descriptor (small font)
.dw _SMLFONT
__endasm;
}
typedef struct {
byte base_ch;
byte frame_x;
byte frame_y;
byte pattern_x;
byte pattern_y;
const byte* chartab;
} FontDescriptor;
#define LOCHAR 0x20
#define HICHAR 0x63
extern const char BIGFONT[HICHAR-LOCHAR+1][7];
extern const char SMLFONT[HICHAR-LOCHAR+1][5];
const FontDescriptor __at(0x206) FNTSYS; // = { 0x20, 8, 8, 1, 7, (byte*)BIGFONT };
const FontDescriptor __at(0x20d) FNTSML; // = { 0xa0, 4, 6, 1, 5, (byte*)SMLFONT };
void hw_interrupt() __interrupt {
CT[0]++;
CT[1]++;
CT[2]++;
CT[3]++;
if (++TMR60 == 60) {
TMR60 = 0;
if (++GTSECS == 60) {
GTMINS++;
}
}
}
const void* const actint_vec = &hw_interrupt;
void STIMER() {
}
void CTIMER() {
}
void bios_init() {
memset((void*)0x4fce, 0, 0x5000-0x4fce);
}
///// INTERPRETER
typedef struct {
union {
struct {
word iy,ix,de,bc,af,hl;
} w;
struct {
byte iyl,iyh,ixl,ixh,e,d,c,b,f,a,l,h;
} b;
} regs;
byte* params;
} ContextBlock;
#define REG_IY 0x1
#define REG_E 0x2
#define REG_D 0x4
#define REG_C 0x8
#define REG_B 0x10
#define REG_IX 0x20
#define REG_A 0x40
#define REG_HL 0x80
#define REG_DE (REG_D|REG_E)
#define REG_BC (REG_B|REG_C)
typedef void (Routine)();
typedef void (SysRoutine)(ContextBlock *ctx);
typedef struct {
SysRoutine* routine;
byte argmask;
} SysCallEntry;
void SYSCALL(ContextBlock *ctx);
void INTPC(ContextBlock *ctx) {
while (ctx->params[0] != 2) { // 2 = exit
SYSCALL(ctx);
}
}
// never called, hopefully
void EXIT(ContextBlock *ctx) {
ctx;
}
// jumps to HL
void RCALL(ContextBlock *ctx) {
((Routine*)ctx->regs.w.hl)();
}
// start interpreting at HL
void MCALL(ContextBlock *ctx) {
ctx; // TODO
}
// exit MCALL loop
void MRET(ContextBlock *ctx) {
ctx; // TODO
}
// jump within MCALL
void MJUMP(ContextBlock *ctx) {
ctx->params = (byte*) ctx->regs.w.hl; // TODO?
}
void suckParams(ContextBlock *ctx, byte argmask) {
byte* dest = (byte*) ctx;
byte* src = ctx->params;
if (argmask & REG_IX) {
ctx->regs.b.ixl = *src++;
ctx->regs.b.ixh = *src++;
}
if (argmask & REG_E)
ctx->regs.b.e = *src++;
if (argmask & REG_D)
ctx->regs.b.d = *src++;
if (argmask & REG_C)
ctx->regs.b.c = *src++;
if (argmask & REG_B)
ctx->regs.b.b = *src++;
if (argmask & REG_A)
ctx->regs.b.a = *src++;
if (argmask & REG_HL) {
ctx->regs.b.l = *src++;
ctx->regs.b.h = *src++;
}
ctx->params = src;
}
void SUCK(ContextBlock* ctx) {
suckParams(ctx, ctx->regs.b.b);
}
void ACTINT(ContextBlock *ctx) {
ctx;
hw_inlin = 200;
hw_infbk = (byte) &actint_vec;
hw_inmod = 8;
__asm
LD A,#0x2 ; I = 0x200
LD I,A
IM 2 ; mode 2
EI ; enable interrupts
__endasm;
}
// Outputs D to port 0A, B to port 09, A to port 0E.
void SETOUT(ContextBlock *ctx) {
hw_verbl = ctx->regs.b.d;
hw_horcb = ctx->regs.b.b;
hw_inmod = ctx->regs.b.a;
}
// sets color palettes from (HL)
void COLSET(ContextBlock *ctx) {
byte* palette = (byte*) ctx->regs.w.hl;
hw_col0r = *palette++;
hw_col1r = *palette++;
hw_col2r = *palette++;
hw_col3r = *palette++;
hw_col0l = *palette++;
hw_col1l = *palette++;
hw_col2l = *palette++;
hw_col3l = *palette++;
}
// Stores A in BC bytes starting at location DE.
void FILL(ContextBlock *ctx) {
byte* dest = (byte*) ctx->regs.w.de;
word count = ctx->regs.w.bc;
byte val = ctx->regs.b.a;
memset(dest, val, count);
}
const char BIGFONT[HICHAR-LOCHAR+1][7] = {/*{count:68,w:8,h:7,brev:1}*/
{ 0x00,0x00,0x00,0x00,0x00,0x00,0x00 },{ 0x00,0x20,0x20,0x20,0x00,0x20,0x00 },{ 0x50,0x50,0x50,0x00,0x00,0x00,0x00 },{ 0x00,0x50,0xF8,0x50,0xF8,0x50,0x00 },{ 0x00,0xF8,0xA0,0xF8,0x28,0xF8,0x00 },{ 0x00,0xC8,0xD0,0x20,0x58,0x98,0x00 },{ 0x00,0xE0,0xA8,0xF8,0x90,0xF8,0x00 },{ 0x40,0x40,0x40,0x00,0x00,0x00,0x00 },{ 0x30,0x20,0x20,0x20,0x20,0x20,0x30 },{ 0x60,0x20,0x20,0x20,0x20,0x20,0x60 },{ 0x00,0x20,0xA8,0x70,0xA8,0x20,0x00 },{ 0x00,0x20,0x20,0xF8,0x20,0x20,0x00 },{ 0x00,0x00,0x00,0x00,0x60,0x60,0x40 },{ 0x00,0x00,0x00,0xF8,0x00,0x00,0x00 },{ 0x00,0x00,0x00,0x00,0x60,0x60,0x00 },{ 0x00,0x08,0x10,0x20,0x40,0x80,0x00 },{ 0x00,0xF8,0x88,0xE8,0x88,0xF8,0x00 },{ 0x00,0x10,0x30,0x50,0x10,0x10,0x00 },{ 0x00,0xF8,0x08,0xF8,0x80,0xF8,0x00 },{ 0x00,0xF8,0x08,0xF8,0x08,0xF8,0x00 },{ 0x00,0x38,0x48,0x88,0xF8,0x08,0x00 },{ 0x00,0xF8,0x80,0xF8,0x08,0xF8,0x00 },{ 0x00,0xF8,0x80,0xF8,0x88,0xF8,0x00 },{ 0x00,0xF8,0x08,0x10,0x20,0x40,0x00 },{ 0x00,0xF8,0x88,0xF8,0x88,0xF8,0x00 },{ 0x00,0xF8,0x88,0xF8,0x08,0xF8,0x00 },{ 0x00,0x30,0x30,0x00,0x30,0x30,0x00 },{ 0x00,0x30,0x30,0x00,0x30,0x30,0x20 },{ 0x08,0x10,0x20,0x40,0x20,0x10,0x08 },{ 0x00,0x00,0xF8,0x00,0xF8,0x00,0x00 },{ 0x40,0x20,0x10,0x08,0x10,0x20,0x40 },{ 0x00,0xF8,0x08,0x78,0x00,0x60,0x00 },{ 0x00,0xF8,0xA8,0xB8,0x80,0xF8,0x00 },{ 0x00,0xF8,0x88,0xF8,0x88,0x88,0x00 },{ 0x00,0xF0,0x90,0xF8,0x88,0xF8,0x00 },{ 0x00,0xF8,0x80,0x80,0x80,0xF8,0x00 },{ 0x00,0xE0,0x90,0x88,0x88,0xF8,0x00 },{ 0x00,0xF8,0x80,0xF8,0x80,0xF8,0x00 },{ 0x00,0xF8,0x80,0xF8,0x80,0x80,0x00 },{ 0x00,0xF8,0x80,0xB8,0x88,0xF8,0x00 },{ 0x00,0x88,0x88,0xF8,0x88,0x88,0x00 },{ 0x00,0x40,0x40,0x40,0x40,0x40,0x00 },{ 0x00,0x08,0x08,0x88,0x88,0xF8,0x00 },{ 0x00,0x88,0x90,0xA0,0x90,0x88,0x00 },{ 0x00,0x80,0x80,0x80,0x80,0xF8,0x00 },{ 0x00,0xFE,0x92,0x92,0x92,0x92,0x00 },{ 0x00,0x88,0xC8,0xA8,0x98,0x88,0x00 },{ 0x00,0xF8,0x88,0x88,0x88,0xF8,0x00 },{ 0x00,0xF8,0x88,0x88,0xF8,0x80,0x00 },{ 0x00,0xF8,0x88,0xA8,0xA8,0xF8,0x10 },{ 0x00,0xF8,0x88,0xF8,0x90,0x88,0x00 },{ 0x00,0xF8,0x80,0xF8,0x08,0xF8,0x00 },{ 0x00,0xF8,0x20,0x20,0x20,0x20,0x00 },{ 0x00,0x88,0x88,0x88,0x88,0xF8,0x00 },{ 0x00,0x88,0x88,0x90,0xA0,0xC0,0x00 },{ 0x00,0x92,0x92,0x92,0x92,0xFE,0x00 },{ 0x00,0x88,0x50,0x20,0x50,0x88,0x00 },{ 0x00,0x88,0x88,0xF8,0x08,0xF8,0x00 },{ 0x00,0xF8,0x10,0x20,0x40,0xF8,0x00 },{ 0x38,0x20,0x20,0x20,0x20,0x20,0x38 },{ 0x00,0x80,0x40,0x20,0x10,0x08,0x00 },{ 0x70,0x10,0x10,0x10,0x10,0x10,0x70 },{ 0x00,0x20,0x70,0xA8,0x20,0x20,0x00 },{ 0x00,0x20,0x40,0xF8,0x40,0x20,0x00 },{ 0x00,0x20,0x20,0xA8,0x70,0x20,0x00 },{ 0x00,0x20,0x10,0xF8,0x10,0x20,0x00 },{ 0x00,0x88,0x50,0x20,0x50,0x88,0x00 },{ 0x00,0x20,0x00,0xF8,0x00,0x20,0x00 }};
const char SMLFONT[HICHAR-LOCHAR+1][5] = {/*{count:68,w:5,h:5,brev:1}*/
{ 0x00,0x00,0x00,0x00,0x00 },{ 0x40,0x40,0x00,0x40,0x00 },{ 0xA0,0xA0,0x00,0x00,0x00 },{ 0x60,0xF0,0xF0,0x60,0x00 },{ 0x40,0xE0,0xE0,0x40,0x00 },{ 0x90,0x20,0x40,0x90,0x00 },{ 0xC0,0xB0,0xE0,0xD0,0x00 },{ 0x20,0x40,0x00,0x00,0x00 },{ 0x20,0x40,0x40,0x20,0x00 },{ 0x40,0x20,0x20,0x40,0x00 },{ 0x40,0xE0,0x40,0xA0,0x00 },{ 0x00,0x40,0xE0,0x40,0x00 },{ 0x00,0x00,0x00,0x60,0x20 },{ 0x00,0x00,0xE0,0x00,0x00 },{ 0x00,0x00,0x00,0x40,0x00 },{ 0x20,0x20,0x40,0x40,0x00 },{ 0xE0,0xA0,0xA0,0xE0,0x00 },{ 0xC0,0x40,0x40,0xE0,0x00 },{ 0xE0,0x20,0xC0,0xE0,0x00 },{ 0xE0,0x60,0x20,0xE0,0x00 },{ 0xA0,0xA0,0xE0,0x20,0x00 },{ 0xE0,0xC0,0x20,0xE0,0x00 },{ 0xC0,0x80,0xE0,0xE0,0x00 },{ 0xE0,0x20,0x40,0x40,0x00 },{ 0x60,0xE0,0xA0,0xE0,0x00 },{ 0xE0,0xE0,0x20,0x60,0x00 },{ 0x00,0x40,0x00,0x40,0x00 },{ 0x00,0x40,0x00,0x60,0x20 },{ 0x00,0x20,0x40,0x20,0x00 },{ 0x00,0xE0,0x00,0xE0,0x00 },{ 0x00,0x40,0x20,0x40,0x00 },{ 0xE0,0x20,0x60,0x00,0x40 },{ 0xF0,0x90,0x10,0xD0,0xF0 },{ 0x60,0xA0,0xE0,0xA0,0x00 },{ 0xC0,0xE0,0xA0,0xE0,0x00 },{ 0x60,0x80,0x80,0xE0,0x00 },{ 0xC0,0xA0,0xA0,0xC0,0x00 },{ 0xE0,0xC0,0x80,0xE0,0x00 },{ 0xE0,0xC0,0x80,0x80,0x00 },{ 0x60,0x80,0xA0,0xE0,0x00 },{ 0xA0,0xA0,0xE0,0xA0,0x00 },{ 0xE0,0x40,0x40,0xE0,0x00 },{ 0x60,0x20,0xA0,0xE0,0x00 },{ 0xA0,0xC0,0xC0,0xA0,0x00 },{ 0x80,0x80,0x80,0xE0,0x00 },{ 0xE0,0xE0,0xE0,0xA0,0x00 },{ 0xE0,0xA0,0xA0,0xA0,0x00 },{ 0xE0,0xA0,0xA0,0xE0,0x00 },{ 0xE0,0xA0,0xE0,0x80,0x00 },{ 0xE0,0xA0,0xE0,0xF0,0x00 },{ 0xE0,0xA0,0xC0,0xA0,0x00 },{ 0xE0,0x80,0x60,0xE0,0x00 },{ 0xE0,0x40,0x40,0x40,0x00 },{ 0xA0,0xA0,0xA0,0xE0,0x00 },{ 0xA0,0xA0,0xC0,0x80,0x00 },{ 0xA0,0xE0,0xE0,0xE0,0x00 },{ 0xA0,0x40,0xA0,0xA0,0x00 },{ 0xA0,0xE0,0x40,0x40,0x00 },{ 0xE0,0x20,0x40,0xE0,0x00 },{ 0x60,0x40,0x40,0x60,0x00 },{ 0x40,0x40,0x20,0x20,0x00 },{ 0x60,0x20,0x20,0x60,0x00 },{ 0x40,0xA0,0x00,0x00,0x00 },{ 0x00,0x00,0x00,0x00,0xF0 },{ 0x80,0x40,0x00,0x00,0x00 },{ 0x00,0x60,0xA0,0xE0,0x00 },{ 0x80,0xE0,0xA0,0xE0,0x00 },{ 0x00,0x60,0x80,0xE0,0x00 }};
// draw a letter
void draw_char(const FontDescriptor* font, byte ch, byte x, byte y, byte op) {
const byte* src = font->chartab + (ch-font->base_ch)*font->pattern_y;
byte xb = x>>2; // divide x by 4
byte* dest = &vmagic[y][xb]; // destination address
hw_magic = M_SHIFT(x) | M_XPAND | op;
for (byte i=0; i<font->pattern_y; i++) {
char b = *src++;
EXIT_CLIPDEST(dest);
*dest++ = b; // expand lower nibble -> 1st byte
*dest++ = b; // expand upper nibble -> 2nd byte
*dest++ = 0; // leftover -> 3rd byte
*dest = 0; // reset upper/lower flag
dest += VBWIDTH-3; // we incremented 3 bytes for this line
}
}
#define FONT_IX ((const FontDescriptor*)ctx->regs.w.ix)
void draw_string(ContextBlock *ctx, const char* str, byte x, byte y, byte op) {
do {
byte ch = *str++;
if (!ch) {
ctx->regs.b.e = x;
break;
}
if (ch < 0x20) {
x += 8 * ch;
} else if (ch < 0x64) {
draw_char(&FNTSYS, ch, x, y, op);
x += 8;
} else if (ch >= 0x80) {
draw_char(FONT_IX, ch, x, y, op);
x += FONT_IX->frame_x;
} else {
/*
if (ch & 0x10) {
ctx->regs.b.ixl = *str++;
ctx->regs.b.ixh = *str++;
}
if (ch & 0x1)
ctx->regs.b.e = *str++;
if (ch & 0x2)
ctx->regs.b.d = *str++;
if (ch & 0x4)
ctx->regs.b.c = *str++;
*/
// TODO: only can change font
}
} while (1);
}
// String display routine (pass pointer to string)
void STRDIS2(ContextBlock *ctx, char *str) {
byte opts = ctx->regs.b.c;
byte x = ctx->regs.b.e;
byte y = ctx->regs.b.d;
void* fontdesc = (void*) ctx->regs.w.ix;
hw_xpand = opts & 0xf;
draw_string(ctx, str, x, y, 3&(opts>>4)); // TODO: opts
}
// String display routine
void STRDIS(ContextBlock *ctx) {
char* str = (char*) ctx->regs.w.hl;
STRDIS2(ctx, str);
}
// Character display routine
void CHRDIS(ContextBlock *ctx) {
char chstr[2];
chstr[0] = ctx->regs.b.a;
chstr[1] = 0;
STRDIS2(ctx, chstr);
}
// BCD routine
const char BCDTAB[17] = "0123456789*+,-./";
void DISNUM(ContextBlock *ctx) {
// TODO: options, B
word oldhl = ctx->regs.w.hl;
byte val = *(byte*) oldhl;
char bcdstr[3];
bcdstr[0] = BCDTAB[val >> 4];
bcdstr[1] = BCDTAB[val & 15];
bcdstr[2] = 0;
STRDIS2(ctx, bcdstr);
}
typedef struct {
sbyte xofs, yofs;
byte xsize, ysize;
byte pattern[0];
} PatternBlock;
// TODO
void wait_vsync() {
byte x = TMR60;
while (x == TMR60) ; // wait until timer/60 changes
}
void PAWS(ContextBlock *ctx) {
while (ctx->regs.b.b--) {
wait_vsync();
}
}
// MATH
void RANGED(ContextBlock *ctx) {
/* Algorithm "xor" from p. 4 of Marsaglia, "Xorshift RNGs" */
RANSHT ^= RANSHT << 13;
RANSHT ^= RANSHT >> 17;
RANSHT ^= RANSHT << 5;
if (ctx->regs.b.a == 0) {
ctx->regs.b.a = (byte)RANSHT;
} else {
ctx->regs.b.a = (byte)(RANSHT % ctx->regs.b.a);
}
}
const SysCallEntry SYSCALL_TABLE[64] = {
/* 0 */
{ &INTPC, 0 },
{ &EXIT, 0 },
{ &RCALL, REG_HL },
{ &MCALL, REG_HL },
{ &MRET, 0 },
/* 10 */
{ &MJUMP, REG_HL },
{ &SUCK, REG_B },
{ &ACTINT, 0 },
{ 0, 0 },
{ 0, 0 },
/* 20 */
{ 0, 0 },
{ &SETOUT, REG_D|REG_B|REG_A },
{ &COLSET, REG_HL },
{ &FILL, REG_A|REG_BC|REG_DE },
{ 0, 0 },
/* 30 */
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
/* 40 */
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
/* 50 */
{ &CHRDIS, REG_E|REG_D|REG_C|REG_A },
{ &STRDIS, REG_E|REG_D|REG_C|REG_HL },
{ &DISNUM, REG_E|REG_D|REG_C|REG_HL },
{ 0, 0 },
{ 0, 0 },
/* 60 */
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
/* 70 */
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
/* 80 */
{ &PAWS, REG_B },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
/* 90 */
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
/* 100 */
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
/* 110 */
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ &RANGED, REG_A },
/* 120 */
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
};
void SYSCALL(ContextBlock *ctx) {
byte op = *ctx->params++;
byte argmask;
SysRoutine* routine;
// user-defined?
if (op & 0x80) {
argmask = UMARGT[op>>1];
routine = (SysRoutine*) USERTB[op>>1];
} else {
const SysCallEntry* entry = &SYSCALL_TABLE[op>>1];
argmask = entry->argmask;
routine = entry->routine;
}
// suck params into context block?
if (op & 1) {
suckParams(ctx, argmask);
}
// call the routine
if (routine) {
routine(ctx);
}
}
#ifdef TEST
void main() {
__asm
LD SP,#0x4fce ; position stack below BIOS vars
ld hl,#0x20d
push hl
pop ix
RST 0x38
.db 0 ; INTPC
.db 22+1 ; SETOUT
.db 102*2, 0x1c, 0x08
.db 14 ; ACTINT
.db 24+1 ; COLSET
.dw _main ; palette???
.db 26+1 ; FILL
.dw 0x4000
.dw 90*40
.db 0xaa
.db 52+1 ; draw string
.db 0
.db 32
.db 0x0c
.dw HelloString
.db 52+1 ; draw string
.db 0
.db 48
.db 0x0c
.dw HelloString
.db 50+1 ; draw char
.db 0
.db 64
.db 0x0c
.db 0x40
.db 2 ; EXIT
.loop:
ld hl,#0x4FED
ld a,(hl)
add a,#0x30
RST 0x38
.db 50 ; draw char
jp .loop
HelloString:
.ascii "HELLO WORLD! "
.db 0xc1, 0xc2, 0xc3, 0xc4, 0xc5
.db 0
; Critter Pattern
; Color 0 = White and Color 2 = Black
;
PATERN: .DB 0,0 ; (0,0) Position
.DB 0x02,0x08 ; 2 byte, 8 line pattern size
.DB 0x0A,0xA0 ; 0000101010100000 - . . 2 2 2 2 . .
.DB 0x22,0x88 ; 0010001010001000 - . 2 . 2 2 . 2 .
.DB 0xAA,0xAA ; 1010101010101010 - 2 2 2 2 2 2 2 2
.DB 0x2A,0xA8 ; 0010101010101000 - . 2 2 2 2 2 2 .
.DB 0x08,0x20 ; 0000100000100000 - . . 2 . . 2 . .
.DB 0x20,0x08 ; 0010000000001000 - . 2 . . . . 2 .
.DB 0x08,0x20 ; 0000100000100000 - . . 2 . . 2 . .
.DB 0x00,0x00 ; 0000000000000000 - . . . . . . . .
__endasm;
while (1) ;
}
#endif
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