getting conditional branch now

core/broadway/instructions.cpp

@@ -1,6 +1,17 @@
 #include <broadway/utils.hpp>
+#include "ircolib/log.hpp"
+#include <mem.hpp>
 
 namespace weee::core {
+void broadway::addi(ircolib::u32 instr) {
+    if (utils::RA(instr) == 0) { // lis
+        gpr[utils::RD(instr)] = ircolib::s32(utils::SIMM(instr));
+        return;
+    }
+
+    gpr[utils::RD(instr)] = gpr[utils::RA(instr)] + (ircolib::s32(utils::SIMM(instr)));
+}
+
 void broadway::addis(ircolib::u32 instr) {
     if (utils::RA(instr) == 0) { // lis
         gpr[utils::RD(instr)] = ircolib::s32(utils::SIMM(instr)) << 16;
@@ -11,4 +22,76 @@ void broadway::addis(ircolib::u32 instr) {
 }
 
 void broadway::ori(ircolib::u32 instr) { gpr[utils::RA(instr)] = gpr[utils::RS(instr)] | utils::UIMM(instr); }
+
+void broadway::bx(ircolib::u32 instr) {
+    const bool link = instr & 1;
+    const bool absolute = instr & 2;
+
+    ircolib::s32 LI = (ircolib::s32(instr << 6) >> 6) & 0x03FFFFFC;
+    if (!absolute)
+        LI += pc - 4;
+
+    if (link)
+        lr = pc;
+
+    pc = LI;
+}
+
+void broadway::move_spr(ircolib::u32 instr) {
+    const size_t spr_field = (instr >> 12) & 0x3FF;
+    const size_t direction = (instr >> 1) & 0x3FF;
+
+    if (direction == 339) {
+        switch (spr_field) {
+        case 0x80:
+            gpr[utils::RD(instr)] = lr;
+            break;
+        case 0x90:
+            gpr[utils::RD(instr)] = ctr;
+            break;
+        default:
+            ircolib::panic("broadway::mfspr with unimplemented spr field of value {}", spr_field);
+        }
+
+        return;
+    }
+
+    if (direction == 467) {
+        switch (spr_field) {
+        case 0x80:
+            lr = gpr[utils::RS(instr)];
+            break;
+        case 0x90:
+            ctr = gpr[utils::RS(instr)];
+            break;
+        default:
+            ircolib::panic("broadway::mtspr with unimplemented spr field of value {}", spr_field);
+        }
+
+        return;
+    }
+
+    ircolib::panic("broadway::move_spr with unknown sub op {}", direction);
+}
+
+void broadway::stwu(ircolib::u32 instr, mem &mem) {
+    if (utils::RA(instr) == 0)
+        ircolib::panic("broadway::stwu with ra == 0");
+
+    const ircolib::s32 d = utils::SIMM(instr);
+    const ircolib::u32 EA = gpr[utils::RA(instr)] + d;
+    mem.write(EA, gpr[utils::RS(instr)]);
+    gpr[utils::RA(instr)] = EA;
+}
+
+void broadway::sth(ircolib::u32 instr, mem &mem) {
+    ircolib::u32 b = gpr[utils::RA(instr)];
+    if (utils::RA(instr) == 0)
+        b = 0;
+
+    const ircolib::s32 d = utils::SIMM(instr);
+    const ircolib::u32 EA = b + d;
+
+    mem.write(EA, ircolib::u16(gpr[utils::RS(instr)]));
+}
 } // namespace weee::core

core/broadway/mmio/vi.cpp

@@ -0,0 +1,15 @@
+#include <broadway/mmio/vi.hpp>
+#include "ircolib/log.hpp"
+
+namespace weee::core {
+void video_interface::write(ircolib::u32 addr, ircolib::u16 value) {
+    addr -= 0x0c002000;
+    switch (addr) {
+    case 2:
+        dcr.raw = value;
+        break;
+    default:
+        ircolib::panic("video_interface::write to unimplemented addr 0x{:04X} with value 0x{:04X}", addr, value);
+    }
+}
+} // namespace weee::core

core/broadway/mmio/vi.hpp

@@ -0,0 +1,26 @@
+#pragma once
+#include <ircolib/types.hpp>
+
+namespace weee::core {
+union DCR {
+    struct {
+        unsigned e : 1;
+        unsigned r : 1;
+        unsigned i : 1;
+        unsigned d : 1;
+        unsigned le0 : 2;
+        unsigned le1 : 2;
+        unsigned fmt : 2;
+        unsigned : 6;
+    };
+
+    ircolib::u16 raw;
+};
+
+struct video_interface {
+    void write(ircolib::u32, ircolib::u16);
+
+    private:
+    DCR dcr{};
+};
+} // namespace weee::core