From: Brett Gordon <beretta42@gmail.com>
Date: Thu, 2 Jun 2016 17:53:21 +0000 (-0400)
Subject: coco3: autodetect and use up to 2M of RAM
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=2699cd1ca4a83d6ded2c7b4ac4766c6af761d4ca;p=FUZIX.git

coco3: autodetect and use up to 2M of RAM
---

diff --git a/Kernel/platform-coco3/coco3.s b/Kernel/platform-coco3/coco3.s
index a44e45d1..405c05b2 100644
--- a/Kernel/platform-coco3/coco3.s
+++ b/Kernel/platform-coco3/coco3.s
@@ -37,6 +37,7 @@
 	    .globl nmi_handler
 	    .globl null_handler
 	    .globl video_init
+	    .globl _scanmem
 
             include "kernel.def"
             include "../kernel09.def"
@@ -142,9 +143,16 @@ init_hardware:
 	;; High speed poke
 	sta	0xffd9		; high speed poke
 	;; set system RAM size
-	ldd 	#512
+	jsr	_scanmem	; X = number of pages
+	tfr 	x,d
+	lslb
+	rola
+	lslb
+	rola
+	lslb
+	rola
 	std 	_ramsize
-	ldd 	#512-64
+	subd	#64+16
 	std 	_procmem
 	;; set initial user mmu
 	ldd	#8
diff --git a/Kernel/platform-coco3/config.h b/Kernel/platform-coco3/config.h
index 35649783..d9108dce 100644
--- a/Kernel/platform-coco3/config.h
+++ b/Kernel/platform-coco3/config.h
@@ -17,7 +17,7 @@
 /* We use flexible 16K banks so use the helper */
 #define CONFIG_BANK16
 #define CONFIG_BANKS	4
-#define MAX_MAPS 32-3
+#define MAX_MAPS 128-3
 #define MAPBASE 0x0000
 /* And swapping */
 /* #define SWAPDEV  2051	 */
diff --git a/Kernel/platform-coco3/main.c b/Kernel/platform-coco3/main.c
index 39fcb749..34d95574 100644
--- a/Kernel/platform-coco3/main.c
+++ b/Kernel/platform-coco3/main.c
@@ -33,6 +33,27 @@ void do_beep(void)
 {
 }
 
+/* Scan memory return number of 8k pages found */
+__attribute__((section(".discard")))
+int scanmem(void)
+{
+	volatile uint8_t *mmu=(uint8_t *)0xffa8;
+	volatile uint8_t *ptr=(uint8_t *)0x0100;
+	int i;
+	for( i = 0; i<256; i++ ){
+		*mmu=i;
+		*ptr=0;
+	}
+	*mmu=0;
+	*ptr=0xff;
+	*mmu=1;
+	for( i = 1; i<256 && !*ptr ; )
+		*mmu=++i;
+	*mmu=0;
+	return i;
+}
+
+
 /*
  Map handling: We have flexible paging. Each map table consists
  of a set of pages with the last page repeated to fill any holes.
@@ -41,15 +62,18 @@ void do_beep(void)
 void pagemap_init(void)
 {
     int i;
+    int max = scanmem();
+    
     /*  We have 64 8k pages for a CoCo3 so insert every other one
      *  into the kernel allocator map.
      */
-    for (i = 10; i < 64; i+=2)
+    for (i = 10; i < max ; i+=2)
         pagemap_add(i);
     /* add common page last so init gets it */
     pagemap_add(6);
 }
 
+
 void map_init(void)
 {
 }