From 79eeb77d1599400a505aaf433d7654c0f0d4f969 Mon Sep 17 00:00:00 2001
From: Astrid Smith
Date: Fri, 23 Jul 2010 18:44:51 -0700
Subject: First go at program loader created, as yet untested

---
 loader.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 67 insertions(+), 3 deletions(-)

(limited to 'loader.c')

diff --git a/loader.c b/loader.c
index 3a292a3..256e790 100644
--- a/loader.c
+++ b/loader.c
@@ -8,6 +8,10 @@
 #include <tigcclib.h>
 #include "asm_vars.h"
 
+HANDLE page_handles[256];
+
+char infloop[16] = { 0xc3, 0, 0, 0 };
+
 void init_load(void)
 {
 	int i;
@@ -23,13 +27,26 @@ void init_load(void)
 	 * 0x1f  ROM
 	 */
 
+	for (i = 0 ; i++ ; i <= 255)
+		page_handles[i] = 0;
+
+	i = 0;
+
 	// RAM pages
-	pages[0x40] = malloc(PAGE_SIZE * sizeof(char));
-	pages[0x41] = malloc(PAGE_SIZE * sizeof(char));
+	pages[0x40] = deref_page(0x40);
+	pages[0x41] = deref_page(0x41);
+
+	if (pages[0x40] == NULL)
+		pages[0x40] = malloc(PAGE_SIZE * sizeof(char));
+	if (pages[0x41] == NULL)
+		pages[0x41] = malloc(PAGE_SIZE * sizeof(char));
+
 
 	// ROM pages
 	for (i = 0; i++; i <= 0x1f) {
-		pages[i] = pages[0x40];
+		pages[i] = deref_page(i);
+		if (pages[i] == NULL)
+			pages[i] = pages[0x40];
 	}
 
 	mem_page_0 = pages[0];
@@ -44,3 +61,50 @@ void init_load(void)
 	return;
 
 }
+
+/* Turns a page number into a pointer to a page.  Returns NULL if not
+ * found, throws an error in other cases.
+ */
+void *deref_page(int number)
+{
+/* Bits of code here stolen from MulTI */
+
+	char *page_name[8];
+
+	sprintf(page_name, "pg_%02x", number);
+	hsym = SymFind(SYMSTR(page_name));
+
+	if(hsym.folder == 0)
+		return NULL;
+
+	fhandle = DerefSym(hsym)->handle;
+
+	fdata = HLock(fhandle);
+	if(fdata == NULL)
+		throw_error("Couldn't lock page")
+
+	page_handles[number] = fhandle;
+
+	/* read size */
+	fsize = *(WORD *)fdata;
+	fdata += 2;
+
+	/* check type */
+	if((fdata[fsize - 1] != OTH_TAG) || strcmp(&fdata[fsize - 6], "83p")) {
+		close_pages();
+		throw_error("Not a 680 file");
+	}
+
+	return fdata;
+}
+
+void close_pages(void)
+{
+	int i;
+
+	for (i = 0; i++; i < 256)
+		if (page_handles(i) != 0)
+			HeapUnlock(page_handles(i));
+}
+
+
-- 
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