vram manipulation

Makefile

@@ -16,7 +16,7 @@ bootinfo.txt: load.fth
 	echo "</boot-script></chrp-boot>" >> bootinfo.txt
 kernel.elf: start.elf boot.elf 
 	$(PPC)-ld -Ttext=0x200000 start.elf boot.elf -o kernel.elf
-boot.elf: boot.c memory.h 
+boot.elf: boot.c 
 	$(PPC)-gcc -c boot.c -o boot.elf
 start.elf: start.s
 	$(PPC)-as -c start.s -o start.elf

boot.c

@@ -1,30 +1,71 @@
-#include "memory.h"
-#define beige 0xBE
-#define mac99 0x5A
+#define beige         0xBE
+#define mac99         0x5A
+#define __VRAM__BEIGE 0x80000000
+#define __VRAM__MAC99 0x81000000
+#define __BIOS__BEIGE 0xFFC00000
+#define __BIOS__MAC99 0xFFF00000
 
-void begin(void)
+
+
+unsigned char IO_TYPE;
+unsigned char* p_vram;
+unsigned char* p_bios;
+
+
+
+void get_io_type(void)
 {
-	unsigned char *ptr_beige = 0x80000000;
-	unsigned char *ptr_mac99 = 0x81000000;
-	if (*ptr_beige == beige) IO_TYPE = beige;
-	if (*ptr_mac99 == mac99) IO_TYPE = mac99;
-	init_ptr();
-	clearscreen();
+        if (*(unsigned char*)__VRAM__BEIGE == beige) IO_TYPE = beige;
+	else if (*(unsigned char*)__VRAM__MAC99 == mac99) IO_TYPE = mac99;
+
+}
+void init(void)
+{
+	if (IO_TYPE == beige)
+	{
+                p_vram = __VRAM__BEIGE;
+		p_bios = __BIOS__BEIGE;
+
+	}
+	else if (IO_TYPE == mac99)
+	{
+		p_vram = __VRAM__MAC99;
+		p_bios = __BIOS__MAC99;
+	}
+}
+
+void main(void)
+{
+	get_io_type();
+	init();
+	clearscreen(0x81, 0x83);
 	for(;;);
 }
 
-void init_ptr(void)
+void clearscreen(unsigned char a, unsigned char b)
 {
-	if (IO_TYPE == beige) vram_ptr = beige_vram;
-	if (IO_TYPE == mac99) vram_ptr = mac99_vram;
-}
-
-void clearscreen(void)
-{
-	for (int i = 0; i<10000000; i++)
+	init();
+	for (unsigned int i = 0; i<0x100000; i++)
 	{
-		*vram_ptr = 0xFF;
-		i++;
-		vram_ptr++;
+		*p_vram = a; 
+		p_vram++;
+		*p_vram = b; 
+		p_vram++;
+	}
+}
+
+void noisescreen(void)
+{
+	init();
+	switch(IO_TYPE)
+	{
+		case beige: p_vram = __VRAM__BEIGE;
+		case mac99: p_vram = __VRAM__MAC99;
+	}
+	for (unsigned int i = 0; i<0x200000; i++)
+	{
+		*p_vram = *(p_bios+0x2F0000+i);
+		p_vram++;
+
 	}
 }

memory.h

@@ -1,6 +0,0 @@
-#define beige_vram 0x80000000
-#define mac99_vram 0x81000000
-
-unsigned char IO_TYPE;
-
-unsigned char* vram_ptr;

start.s

@@ -1,3 +1,3 @@
 .globl _start
 _start: 
-b begin 
+b main