hacks/NEDsim/simulator.h

/* (c) 2021 Aaron Taylor <ataylor at subgeniuskitty dot com>                  */
/* See LICENSE.txt file for copyright and license details.                    */

#include <stdbool.h>

/* Bytes per word. */
#define BPW 4

/* Syllables per word. */
#define SPW 5

/* Storage definitions. */
#define STACK_LENGTH     65536
#define RAM_LENGTH       67108864
#define RAM_BASE_ADDRESS 0x20000000

struct NEDpsw {
    bool zero;
    bool negative;
};

struct NEDthread {
    uint32_t stack[STACK_LENGTH];
    uint32_t sp;
    uint32_t pc;
    uint8_t sc;
    struct NEDpsw * psw;
};

struct NEDhack {
    uint32_t iw;
    bool resume_word;
};

struct NEDstate {
    bool halted;
    uint8_t ram[RAM_LENGTH];
    /* Although NED is multi-threaded, this screensaver is restricted to a single thread. */
    struct NEDthread * thread[1];
    struct NEDthread * active_thread;
    struct NEDhack * hack;
};

enum syllables {
    MVSTCK  = 0b00001111,
    JMP     = 0b00001110,
    SWAP    = 0b00001101,
    ADD     = 0b00001100,
    XOR     = 0b00001011,
    NOT     = 0b00001010,
    OR      = 0b00001001,
    AND     = 0b00001000,
    BRZ     = 0b00000111,
    TEST    = 0b00000110,
    CMPSWP  = 0b00000101,
    SHIFT   = 0b00000100,
    STORE   = 0b00000011,
    LOAD    = 0b00000010,
    NOP     = 0b00000001,
    HALT    = 0b00000000
};

struct NEDstate * init_simulator(char * input_file);
struct NEDstate * run_simulator(struct NEDstate * state);
uint32_t ram_r_word(struct NEDstate * state, uint32_t address);