// The OS/K Team licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

#include <sys/time.h>

#include <signal.h>
#include <pc/dev.h>

#define FWPROGSIZE (1024 * 1024 * 1024)
static ssize_t fwsize;
static ushort *fwprog;

ushort bget(ctx_t *ctx)
{
    ulong addr = rip + cr1;

/*
    if (addr % 2) {
        _except(ctx, E_ALI, "Misaligned RIP and/or CR1: "
            "rip=0x%lX cr1=0x%lX",
            rip, cr1);
    }
*/

    if (addr2real(addr) >= ctx->mz) {
        _except(ctx, E_ACC, "Executing out of memory: "
            "rip=0x%lX cr1=0x%lX",
            rip, cr1);
    }

    ushort c = ctx->mp[addr2real(addr)];

    rip += 2;

    return c;
}

ctx_t main_ctx;

void sigcommon(void)
{
    dying = 1;

    enable_stdin_echoing();

    //
    // Shut down devices
    //
    devfiniall(&main_ctx);

    exit(-13);
}

void sigint(int _)
{
    sigcommon();
}

void sigsegv(int _)
{
    log("Segmentation fault\n");
    sigcommon();
}

void main_loop(void)
{
    //
    // Start decoding
    //
    while (1) {
        decode(&main_ctx);

        if (main_ctx.step)
            getchar();
    }
}

int main(int argc, char **argv)
{
    FILE *fwfile;

    main_ctx.r = arch_r;
    main_ctx.i = arch_i;

    //
    // srand
    //
    struct timeval time;
    gettimeofday(&time, NULL);
    srandom((time.tv_sec * 1000) + (time.tv_usec / 1000));

    //
    // Signal handling
    //
    signal(SIGINT, sigint);
    signal(SIGBUS, sigsegv);
    signal(SIGSEGV, sigsegv);

    //
    // Load program
    //
    if (argc < 2) {
        log("Not enough arguments\n");
        exit(-3);
    }

    fwfile = fopen(argv[1], "rb");

    if (!fwfile) {
        log("Couldn't open program file\n");
        exit(-2);
    }

    fwprog = malloc(FWPROGSIZE);

    if (!fwprog) {
        log("Couldn't allocate firmware buffer\n");
        exit(-1);
    }

    fwsize = fread(fwprog, 1, FWPROGSIZE, fwfile);

    if (fwsize < 2) {
        log("Program file too small or empty\n");
        free(fwprog);
        exit(-3);
    }

    fclose(fwfile);

    //
    // Register frame allocation
    //
    main_ctx.rf = calloc(NREGS, sizeof(ulong));

    //
    // Memory allocation
    //
    main_ctx.mp = malloc(MEMSIZE + 16);
    main_ctx.mz = MEMSIZE;

    main_ctx.get = bget;

    main_ctx.rf[RIP] = MEMOFF;

    if (main_ctx.mp == 0) {
        log("Couldn't allocate RAM\n");
        free(main_ctx.rf);
        free(fwprog);
        exit(-1);
    }

    memcpy(&main_ctx.mp[addr2real(main_ctx.rf[RIP])], fwprog, fwsize);

    //
    // Devices initialization
    //
    main_ctx.dh = 0;
    if (devinitall(&main_ctx) < 0) {
        log("Couldn't initialize devices\n");
        free(main_ctx.rf);
        free(fwprog);
        exit(-10);
    }

    disable_stdin_echoing();
    main_loop();
}