jank-mmb3-isr-debug.patch

$ git diff
diff --git a/src/arm/arm.c b/src/arm/arm.c
index 37dfe726c..89ad3d900 100644
--- a/src/arm/arm.c
+++ b/src/arm/arm.c
@@ -4,6 +4,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include <mgba/internal/arm/arm.h>
+#include <mgba-util/common.h>

 #include <mgba/internal/arm/isa-arm.h>
 #include <mgba/internal/arm/isa-inlines.h>
@@ -216,8 +217,31 @@ static inline void ARMStep(struct ARMCore* cpu) {
        instruction(cpu, opcode);
 }

+static struct ARMCore* g_bound_cpu;
+static bool g_is_tracing = false;
+
 static inline void ThumbStep(struct ARMCore* cpu) {
+       struct ARMCore* bound_cpu = NULL;
+       if (ATOMIC_CMPXCHG(g_bound_cpu, bound_cpu, cpu)) {
+               fprintf(stderr, "bound cpu @ %p\n", cpu);
+               bound_cpu = cpu;
+       }
+
        uint32_t opcode = cpu->prefetch[0];
+       if (bound_cpu == cpu) {
+               if (cpu->gprs[ARM_PC] == 0x08006440) {
+                       ATOMIC_STORE(g_is_tracing, true);
+               } else if (cpu->gprs[ARM_PC] == 0x08006442) {
+                       ATOMIC_STORE(g_is_tracing, false);
+                       fprintf(stderr, "trace end\n");
+               }
+               bool is_tracing;
+               ATOMIC_LOAD(is_tracing, g_is_tracing);
+               if (is_tracing) {
+                       fprintf(stderr, "trace: pc = %08x, lr = %08x, opcode = %04x\n", cpu->gprs[ARM_PC], cpu->gprs[14], opcode);
+               }
+       }
+
        cpu->prefetch[0] = cpu->prefetch[1];
        cpu->gprs[ARM_PC] += WORD_SIZE_THUMB;
        LOAD_16(cpu->prefetch[1], cpu->gprs[ARM_PC] & cpu->memory.activeMask, cpu->memory.activeRegion);
diff --git a/src/debugger/debugger.c b/src/debugger/debugger.c
index cc6beab9c..da160bb9d 100644
--- a/src/debugger/debugger.c
+++ b/src/debugger/debugger.c
@@ -9,6 +9,7 @@

 #include <mgba/internal/debugger/cli-debugger.h>
 #include <mgba/internal/debugger/symbols.h>
+#include <mgba/internal/arm/debugger/debugger.h>

 #ifdef USE_GDB_STUB
 #include <mgba/internal/debugger/gdb-stub.h>
@@ -67,6 +68,8 @@ struct mDebugger* mDebuggerCreate(enum mDebuggerType type, struct mCore* core) {
        return &debugger->d;
 }

+void ARMRunFake(struct ARMCore* cpu, uint32_t opcode);
+
 void mDebuggerAttach(struct mDebugger* debugger, struct mCore* core) {
        debugger->d.id = DEBUGGER_ID;
        debugger->d.init = mDebuggerInit;
diff --git a/src/gba/gba.c b/src/gba/gba.c
index de79671c5..3b272ecde 100644
--- a/src/gba/gba.c
+++ b/src/gba/gba.c
@@ -813,6 +813,7 @@ void GBAIllegal(struct ARMCore* cpu, uint32_t opcode) {

 void GBABreakpoint(struct ARMCore* cpu, int immediate) {
        struct GBA* gba = (struct GBA*) cpu->master;
+       if (immediate == 0xef) { ARMRunFake(cpu, 0x1c04); }
        if (immediate >= CPU_COMPONENT_MAX) {
                return;
        }
@@ -968,6 +969,7 @@ void GBASetBreakpoint(struct GBA* gba, struct mCPUComponent* component, uint32_t
                value |= immediate & 0xFF;
                GBAPatch16(gba->cpu, address, value, &old);
                *opcode = (uint16_t) old;
+               fprintf(stderr, "trace: set breakpoint at %08x, old = %04x, new = %04x\n", address, *opcode, value);
        }
 }

STUFF.md

replace 0x0000643E in MEGA_EXE3_BLA3XE with EF BE (should be 04 1C originally)