From cc4d044f2827e10a58c15002a95d1e78dc819fa3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Magalh=C3=A3es?= <joamag@gmail.com>
Date: Mon, 14 Nov 2022 23:59:17 +0000
Subject: [PATCH] feat: more generic boot loading
---
src/gb.rs | 6 +++++-
src/mmu.rs | 11 ++++++++++-
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/src/gb.rs b/src/gb.rs
index 1dcc81e3..70234c9c 100644
--- a/src/gb.rs
+++ b/src/gb.rs
@@ -124,7 +124,11 @@ impl GameBoy {
}
pub fn load_boot_default(&mut self) {
- self.load_boot_static(BootRom::DmgBootix);
+ self.load_boot_dmg();
+ }
+
+ pub fn load_boot_dmg(&mut self) {
+ self.load_boot_static(BootRom::Cgb);
}
pub fn load_boot_cgb(&mut self) {
diff --git a/src/mmu.rs b/src/mmu.rs
index abe5aa46..be0c48b6 100644
--- a/src/mmu.rs
+++ b/src/mmu.rs
@@ -1,6 +1,6 @@
use crate::{debugln, pad::Pad, ppu::Ppu, rom::Cartridge, timer::Timer};
-pub const BOOT_SIZE: usize = 256;
+pub const BOOT_SIZE: usize = 2304;
pub const RAM_SIZE: usize = 8192;
pub struct Mmu {
@@ -30,7 +30,16 @@ pub struct Mmu {
/// the boot sequence has been finished.
boot_active: bool,
+ /// Buffer to be used to store the boot ROM, this is the code
+ /// that is going to be executed at the beginning of the Game
+ /// Boy execution. The buffer effectively used is of 256 bytes
+ /// for the "normal" Game Boy (MGB) and 2308 bytes for the
+ /// Game Boy Color (CGB). Note that in the case of the CGB
+ /// the bios which is 2308 bytes long is in fact only 2048 bytes
+ /// as the 256 bytes in range 0x100-0x1FF are meant to be
+ /// overwritten byte the cartridge header.
boot: [u8; BOOT_SIZE],
+
ram: [u8; RAM_SIZE],
}
--
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