From e4abf1dbcc23bb0d2849072df4e86f5109a3b10a Mon Sep 17 00:00:00 2001
From: meepingsnesroms <guicrith@gmail.com>
Date: Fri, 3 Feb 2017 11:23:58 -0800
Subject: [PATCH] Bootloader and gba mode work together,fixed string = null bug

---
 libgambatte/src/bootloader.cpp | 16 ++++++++++++++--
 libgambatte/src/bootloader.h   |  2 +-
 libgambatte/src/gambatte.cpp   | 12 ++++++------
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/libgambatte/src/bootloader.cpp b/libgambatte/src/bootloader.cpp
index 2af98ab..e0349c3 100644
--- a/libgambatte/src/bootloader.cpp
+++ b/libgambatte/src/bootloader.cpp
@@ -25,10 +25,17 @@ static bool gbc_mode;
 
 
 
+static void patch_gbc_to_gba_mode(){
+   /*moves one jump over another and puts ld b,0x01 into the original position*/
+   uint16_t patchloc = 0xF2;
+   uint8_t patch[0x7] = {0xCD,0xD0,0x05/*<-call systemsetup*/,0x06,0x01/*<-ld b,0x1*/,0x00/*<-nop*/,0x00/*<-nop*/};
+   memcpy(bootromswapspace + patchloc,patch,0x7);
+}
+
 //this is the only retroarch specific function,everything else can just be copied over
 static std::string get_bootloader_path(std::string bootloadername){
    std::string path;
-   if(bootrompath != NULL){
+   if(bootrompath[0] != 0){
       path = bootrompath;
       if(path[path.length() - 1] != '/')path += '/';
       path += bootloadername;
@@ -47,7 +54,7 @@ bool have_bootloader(bool isgbc){
    return exist(path);
 }
 
-bool loadbootloader(bool isgbc){
+bool loadbootloader(bool isgbc,bool isgba){
    unsigned int size;
    std::string path;
    int n = 0;
@@ -71,6 +78,10 @@ bool loadbootloader(bool isgbc){
    using_bootloader = true;
    gbc_mode = isgbc;
    
+   if(isgba){//patch bootloader to fake gba mode
+      patch_gbc_to_gba_mode();
+   }
+   
    //backup rom segment that is shared with bootloader
    memcpy(rombackup,(uint8_t*)addrspace_start,size);
    
@@ -88,6 +99,7 @@ void resetbootloader(){
    has_called_FF50 = false;
    addrspace_start = NULL;
    using_bootloader = false;
+   gbc_mode = false;
 }
 
 void set_bootrom_directory(char* dir){
diff --git a/libgambatte/src/bootloader.h b/libgambatte/src/bootloader.h
index 27a8dc3..77f86e8 100644
--- a/libgambatte/src/bootloader.h
+++ b/libgambatte/src/bootloader.h
@@ -1,6 +1,6 @@
 //load the rom then call the loadbootloader() function before execution starts
 bool have_bootloader(bool isgbc);
-bool loadbootloader(bool isgbc);
+bool loadbootloader(bool isgbc,bool isgba);
 void resetbootloader();
 
 void set_bootrom_directory(char* dir);
diff --git a/libgambatte/src/gambatte.cpp b/libgambatte/src/gambatte.cpp
index 1499a97..b16a8d8 100644
--- a/libgambatte/src/gambatte.cpp
+++ b/libgambatte/src/gambatte.cpp
@@ -61,13 +61,13 @@ void GB::reset() {
    p_->cpu.setStatePtrs(state);
    setInitState(state, p_->cpu.isCgb(), p_->gbaCgbMode);
    
-   if(bootloaderexists && !p_->gbaCgbMode){
+   if(bootloaderexists){
       resetbootloader();
       set_address_space_start((void*)p_->cpu.rombank0_ptr());
-      loadbootloader(p_->cpu.isCgb());
+      loadbootloader(p_->cpu.isCgb(), p_->gbaCgbMode);
       state.cpu.pc = 0x0000;
       //the hw registers must be zeroed out to prevent the logo from being garbled
-      memset((void*)(state.mem.ioamhram.get() + 0x100),0x00,0x100);
+      memset((void*)(state.mem.ioamhram.get() + 0x100), 0x00, 0x100);
    }
 
    p_->cpu.loadState(state);
@@ -93,13 +93,13 @@ void GB::Priv::on_load_succeeded(unsigned flags)
    cpu.setStatePtrs(state);
    setInitState(state, cpu.isCgb(), gbaCgbMode);
    
-   if(bootloaderexists && !gbaCgbMode){
+   if(bootloaderexists){
       resetbootloader();
       set_address_space_start((void*)cpu.rombank0_ptr());
-      loadbootloader(cpu.isCgb());
+      loadbootloader(cpu.isCgb(), gbaCgbMode);
       state.cpu.pc = 0x0000;
       //the hw registers must be zeroed out to prevent the logo from being garbled
-      memset((void*)(state.mem.ioamhram.get() + 0x100),0x00,0x100);
+      memset((void*)(state.mem.ioamhram.get() + 0x100), 0x00, 0x100);
    }
    
    cpu.loadState(state);