From f3125a2b0bf1c95a6fa587317c205f3d0197cdba Mon Sep 17 00:00:00 2001
From: Tobias Gunkel <tobias.gunkel@gmx.de>
Date: Sun, 24 Aug 2025 09:08:58 +0200
Subject: [PATCH] add rom boot read

---
 .gitignore   |  5 ++++-
 src/gb.cpp   | 29 +++++++++++++++++++++++++----
 src/gb.h     |  2 +-
 src/main.cpp |  6 +-----
 4 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/.gitignore b/.gitignore
index d512e27..fe0f632 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,7 @@ build
 uf2
 .pio
 .vscode
-*_bin.h
\ No newline at end of file
+*_bin.h
+*.bin
+*.gb
+*.gbc
diff --git a/src/gb.cpp b/src/gb.cpp
index 6aadd35..9ed3f44 100644
--- a/src/gb.cpp
+++ b/src/gb.cpp
@@ -63,8 +63,29 @@ static void gb_error(struct gb_s* gb, const enum gb_error_e gb_err, const uint16
   error(String("Error ") + gb_err + " occurred: " + gb_err_str[gb_err] + " at 0x" + String(addr, 16));
 }
 
-gb_init_error_e initGbContext() {
-  memcpy(rom_bank0, rom, sizeof(rom_bank0));
-  return gb_init(&gb, &gb_rom_read, &gb_cart_ram_read,
-      &gb_cart_ram_write, &gb_error, NULL);
+#ifdef USE_BOOT_ROM
+#include "boot_cgb_bin.h"
+#include "boot_gb_bin.h"
+static uint8_t gb_bootrom_read(struct gb_s* gb, const uint_fast16_t addr) {
+	if (gb->cgb.cgbMode) {
+    return CGB_BOOT_ROM[addr];
+  } else {
+    return GB_BOOT_ROM[addr];
+  }
+}
+#endif
+
+void initGbContext() {
+  memcpy(rom_bank0, rom, sizeof(rom_bank0));
+
+  auto ret = gb_init(&gb, &gb_rom_read, &gb_cart_ram_read, &gb_cart_ram_write, &gb_error, NULL);
+  if (ret != GB_INIT_NO_ERROR) {
+    error(String("Error initializing emulator: ") + ret);
+  }
+
+#ifdef USE_BOOT_ROM
+  // gb_bootrom_read has to be set after gb_init(), as it sets it to NULL
+  gb_set_bootrom(&gb, &gb_bootrom_read);
+  gb_reset(&gb);
+#endif
 }
diff --git a/src/gb.h b/src/gb.h
index b968942..6be0601 100644
--- a/src/gb.h
+++ b/src/gb.h
@@ -13,4 +13,4 @@ extern const uint8_t* rom;
 #define RAM_SIZE 32768
 extern uint8_t ram[RAM_SIZE];
 
-gb_init_error_e initGbContext();
+void initGbContext();
diff --git a/src/main.cpp b/src/main.cpp
index 51ec2ac..e826e1e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -64,11 +64,7 @@ void startEmulator() {
 #endif
 
   Serial.println("Init GB context ...");  
-  auto ret = initGbContext();
-  if (ret != GB_INIT_NO_ERROR) {
-    Serial.printf("Error: %d\n", ret);
-    reset();
-  }
+  initGbContext();
 
   /* Automatically assign a colour palette to the game */
   char rom_title[16];