// 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/device.h>
#include <pc/console.h>

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

ushort bget(ctx_t *ctx)
{
    ulong addr = R(RIP) + R(CR1);

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

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

    R(RIP) += 2;

    return c;
}

ctx_t main_ctx;

void sigcommon(void)
{
    _except(&main_ctx, E_BRK, "SIGNAL'ed");
}

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

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

jmp_buf exc_jmp_buf;

//
// Main loop
//
void main_loop(void)
{
    if (main_ctx.dumpsw)
        trace("\n\n\n");

    setjmp(exc_jmp_buf);

    //
    // Start decoding
    //
    while (!dying) {
        // Execute one instruction
        decode(&main_ctx);

        console_update(&main_ctx);
    }

    die(0);
}

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

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

#if 0 && defined(NDEBUG)
    main_ctx.dumpsw = 1;
#endif

    //
    // 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 < 3) {
        logerr("Not enough arguments\n");
        exit(-3);
    }

    create_symtab(argv[2]);

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

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

    fwprog = malloc(FWPROGSIZE);

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

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

    if (fwsize < 2) {
        logerr("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) {
        logerr("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) {
        logerr("Couldn't initialize devices\n");
        free(main_ctx.rf);
        free(fwprog);
        exit(-10);
    }

    // To be moved to some screen device
    console_init(&main_ctx);

    main_loop();
}