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

#include "arch.h"

// Boot firware, loaded at MEMOFF (1MB)
ushort fwprog[] = {
    I_MOV_R_I, RBP, A_IMM32, FWSTACK>>16, FWSTACK&0xFF,
    I_MOV_R_I, RSP, A_IMM32, FWSTACK>>16, FWSTACK&0xFF,
    
    I_MOV_M_I, A_MEM, RBP, A_IMM16, 0xAC,
    I_SUB_R_I, RBP, A_IMM16, 8,
    I_ADD_M_R, A_OFF, 8, RBP, RSP,
    I_MOV_R_M, RAX, A_MEM, RBP, 
};

ushort bget(ctx_t *ctx)
{
    if (addr2real(ctx->r[RIP].val) >= MEMSIZE) {
        _except(ctx, E_ACC, "Executing out of memory");
    }
    
    ushort c = ctx->mp[addr2real(ctx->r[RIP].val)];
    
    ctx->r[RIP].val++;
    
    return c;
}

extern reg_t arch_r[NREGS];
extern instr_t arch_i[NINSTRS];

int main(void)
{
    static ctx_t main_ctx;
    
    main_ctx.r = arch_r;
    main_ctx.i = arch_i;
    
    main_ctx.mp = malloc(MEMSIZE);
    main_ctx.mz = MEMSIZE;
    
    main_ctx.get = bget;
    
    main_ctx.r[RIP].val = MEMOFF;
    
    if (main_ctx.mp == 0) {
        log("Couldn't allocate RAM");
        exit(-1);
    }
    
    memcpy(&main_ctx.mp[addr2real(main_ctx.r[RIP].val)], fwprog, sizeof(fwprog));
    memset(&main_ctx.mp[addr2real(main_ctx.r[RIP].val) + sizeof(fwprog)/2], 0xFF, 0xFF);

    while (1) {
        decode(&main_ctx);
    }

    return 0;
}