refactor: reorganize everything

Signed-off-by: Amneesh Singh <natto@weirdnatto.in>

include/cpu/psr.hh

@@ -0,0 +1,123 @@
+#pragma once
+
+#include <cstdint>
+#include <fmt/ostream.h>
+
+namespace matar {
+enum class Mode {
+    /* M[4:0] in PSR */
+    User       = 0b10000,
+    Fiq        = 0b10001,
+    Irq        = 0b10010,
+    Supervisor = 0b10011,
+    Abort      = 0b10111,
+    Undefined  = 0b11011,
+    System     = 0b11111,
+};
+
+enum class State {
+    Arm   = 0,
+    Thumb = 1
+};
+
+enum class Condition {
+    EQ = 0b0000,
+    NE = 0b0001,
+    CS = 0b0010,
+    CC = 0b0011,
+    MI = 0b0100,
+    PL = 0b0101,
+    VS = 0b0110,
+    VC = 0b0111,
+    HI = 0b1000,
+    LS = 0b1001,
+    GE = 0b1010,
+    LT = 0b1011,
+    GT = 0b1100,
+    LE = 0b1101,
+    AL = 0b1110
+};
+
+constexpr auto
+stringify(Condition cond) {
+
+#define CASE(cond)                                                             \
+    case Condition::cond:                                                      \
+        return #cond;
+
+    switch (cond) {
+        CASE(EQ)
+        CASE(NE)
+        CASE(CS)
+        CASE(CC)
+        CASE(MI)
+        CASE(PL)
+        CASE(VS)
+        CASE(VC)
+        CASE(HI)
+        CASE(LS)
+        CASE(GE)
+        CASE(LT)
+        CASE(GT)
+        CASE(LE)
+        case Condition::AL: {
+            return "";
+        }
+    }
+
+#undef CASE
+
+    return "";
+}
+
+class Psr {
+  public:
+    // clear the reserved bits i.e, [8:27]
+    Psr(uint32_t raw);
+
+    uint32_t raw() const;
+    void set_all(uint32_t raw);
+
+    // Mode : [4:0]
+    Mode mode() const;
+    void set_mode(Mode mode);
+
+    // State : [5]
+    State state() const;
+    void set_state(State state);
+
+#define GET_SET_NTH_BIT_FUNCTIONS(name)                                        \
+    bool name() const;                                                         \
+    void set_##name(bool val);
+
+    // FIQ disable : [6]
+    GET_SET_NTH_BIT_FUNCTIONS(fiq_disabled)
+
+    // IRQ disable : [7]
+    GET_SET_NTH_BIT_FUNCTIONS(irq_disabled)
+
+    // Reserved bits : [27:8]
+
+    // Overflow flag : [28]
+    GET_SET_NTH_BIT_FUNCTIONS(v)
+
+    // Carry flag : [29]
+    GET_SET_NTH_BIT_FUNCTIONS(c)
+
+    // Zero flag : [30]
+    GET_SET_NTH_BIT_FUNCTIONS(z)
+
+    // Negative flag : [30]
+    GET_SET_NTH_BIT_FUNCTIONS(n)
+
+#undef GET_SET_NTH_BIT_FUNCTIONS
+
+    bool condition(Condition cond) const;
+
+  private:
+    static constexpr uint32_t PSR_CLEAR_RESERVED = 0xF00000FF;
+    static constexpr uint32_t PSR_CLEAR_MODE     = 0xFFFFFFE0;
+
+    uint32_t psr;
+};
+}