all repos — xyw @ a37b6851e9265dadbec0aba7a41f25360cf7f488

A minimal virtual machine and assembler for terminals.

devices/system.c

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#include <time.h>
#include <stdlib.h>
#include <stdio.h>
#include "../xyw.h"

#define SYSTEM_STATE 0x00
#define SYSTEM_ERROR 0x01
#define SYSTEM_PAGE 0x02
#define SYSTEM_RANDOM 0x03
#define SYSTEM_IMAGE_EXEC 0x06

void system_setup(xyw_byte *data)
{
    (void)data;
    srand(time(NULL));
}

xyw_byte system_input(xyw_byte *data, xyw_byte addr, xyw_byte *error)
{
    if (addr == SYSTEM_RANDOM)
        return (xyw_byte)(rand() & 0xFF);
    (void)error;
    return data[addr];
}

void system_output(xyw_byte *data, xyw_byte addr, xyw_byte *error)
{
    (void)error;
    if (addr == SYSTEM_IMAGE_EXEC + 1)
    {
        xyw_word target = XYW_PEEKW(&data[SYSTEM_IMAGE_EXEC]);
        if (target != 0)
            xyw_request_exec(target);
    }
}