From 57bcf43b1dd7d10aa1389be288a7193efb16f56c Mon Sep 17 00:00:00 2001
From: sorgelig <pour.garbage@gmail.com>
Date: Thu, 13 Dec 2018 20:02:01 +0800
Subject: [PATCH] SNES: update parser with chip detection.

---
 support/snes/snes.cpp | 102 +++++++++++++++++++++++++++++++++++++-----
 1 file changed, 90 insertions(+), 12 deletions(-)

diff --git a/support/snes/snes.cpp b/support/snes/snes.cpp
index 0f897e8..85616f1 100644
--- a/support/snes/snes.cpp
+++ b/support/snes/snes.cpp
@@ -126,35 +126,113 @@ static uint32_t find_header(const uint8_t *data, uint32_t size)
 uint8_t* snes_get_header(fileTYPE *f)
 {
 	memset(hdr, 0, sizeof(hdr));
-	uint8_t *buf = (uint8_t*)malloc(f->size);
-	if (buf)
+	uint32_t size = f->size;
+	uint8_t *prebuf = (uint8_t*)malloc(size);
+	if (prebuf)
 	{
 		FileSeekLBA(f, 0);
-		if (FileReadAdv(f, buf, f->size))
+		if (FileReadAdv(f, prebuf, size))
 		{
-			uint32_t addr = find_header(buf, f->size);
+			uint8_t *buf = prebuf;
+
+			if (size & 512)
+			{
+				buf += 512;
+				size -= 512;
+			}
+
+			*(uint32_t*)(&hdr[8]) = size;
+
+			uint32_t addr = find_header(buf, size);
 			if (addr)
 			{
-				uint8_t romsz = buf[addr + RomSize];
 				uint8_t ramsz = buf[addr + RamSize];
-				if (romsz >= 0x10) romsz = 0;
 				if (ramsz >= 0x08) ramsz = 0;
-				hdr[0] = (ramsz << 4) | romsz;
 
-				hdr[1] = (addr == 0x00ffc0) ? 1 : (addr == 0x40ffc0) ? 5 : 0; //LHRom type
+				//Rom type: 0-Low, 1-High, 2-ExHigh
+				hdr[1] = (addr == 0x00ffc0) ? 1 : (addr == 0x40ffc0) ? 2 : 0;
 
-				hdr[2] = buf[addr + RomType];
+				//DSPn types 8..B
+				if ((buf[addr + Mapper] == 0x20 || buf[addr + Mapper] == 0x21) && buf[addr + RomType] == 0x03)
+				{	//DSP1
+					hdr[1] |= 0x80;
+				}
+				else if (buf[addr + Mapper] == 0x30 && buf[addr + RomType] == 0x05 && buf[addr + Company] != 0xb2)
+				{	//DSP1
+					hdr[1] |= 0x80;
+				}
+				else if (buf[addr + Mapper] == 0x31 && (buf[addr + RomType] == 0x03 || buf[addr + RomType] == 0x05))
+				{	//DSP1
+					hdr[1] |= 0x80;
+				}
+				else if (buf[addr + Mapper] == 0x20 && buf[addr + RomType] == 0x05)
+				{	//DSP2
+					hdr[1] |= 0x90;
+				}
+				else if (buf[addr + Mapper] == 0x30 && buf[addr + RomType] == 0x05 && buf[addr + Company] == 0xb2)
+				{	//DSP3
+					hdr[1] |= 0xA0;
+				}
+				else if (buf[addr + Mapper] == 0x30 && buf[addr + RomType] == 0x03)
+				{	//DSP4
+					hdr[1] |= 0xB0;
+				}
 
+				//CX4 4
+				if (buf[addr + Mapper] == 0x20 && buf[addr + RomType] == 0xf3)
+				{
+					hdr[1] |= 0x40;
+				}
+
+				//SDD1 5
+				if (buf[addr + Mapper] == 0x32 && (buf[addr + RomType] == 0x43 || buf[addr + RomType] == 0x45))
+				{
+					hdr[1] |= 0x50;
+				}
+
+				//SA1 6
+				if (buf[addr + Mapper] == 0x23 && (buf[addr + RomType] == 0x32 || buf[addr + RomType] == 0x34 || buf[addr + RomType] == 0x35))
+				{
+					hdr[1] |= 0x60;
+				}
+
+				//GSU 7
+				if (buf[addr + Mapper] == 0x20 && (buf[addr + RomType] == 0x13 || buf[addr + RomType] == 0x14 || buf[addr + RomType] == 0x15 || buf[addr + RomType] == 0x1a))
+				{
+					ramsz = buf[addr - 3];
+					if (ramsz == 0xFF) ramsz = 5; //StarFox
+					if (ramsz > 6) ramsz = 6;
+					hdr[1] |= 0x70;
+				}
+
+				//1..3,C..F - reserved for other mappers.
+
+				hdr[2] = 0;
+
+				//PAL Regions
 				if ((buf[addr + CartRegion] >= 0x02 && buf[addr + CartRegion] <= 0x0C) || buf[addr + CartRegion] == 0x11)
-				{ //PAL Regions
+				{	
 					hdr[3] |= 1;
 				}
 
-				*(uint32_t*)(&hdr[4]) = addr;
+				//re-calc rom size
+				uint8_t romsz = 15;
+				size--;
+				if (!(size & 0xFF000000))
+				{
+					while (!(size & 0x1000000))
+					{
+						romsz--;
+						size <<= 1;
+					}
+				}
+				hdr[0] = (ramsz << 4) | romsz;
+				printf("Size from header: 0x%X, calculated size: 0x%X\n", buf[addr + RomSize], romsz);
 			}
+			*(uint32_t*)(&hdr[4]) = addr;
 		}
 		FileSeekLBA(f, 0);
-		free(buf);
+		free(prebuf);
 	}
 	return hdr;
 }