# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1456597232 -3600
# Node ID d323b7b054242034056bf9c1f013e1f2746ddcfc
# Parent  4502cd6c72549075041124c1e0f1053dca9e3058
Put the page tables and the stacks in unmapped space, with the stacks occupying
distinct virtual addresses and thus not employing the page tables.

diff -r 4502cd6c7254 -r d323b7b05424 stage2/cpu.c
--- a/stage2/cpu.c	Sat Feb 27 18:34:50 2016 +0100
+++ b/stage2/cpu.c	Sat Feb 27 19:20:32 2016 +0100
@@ -177,7 +177,7 @@
 	/* Wire in the kseg0 mapping and the page tables. */
 
 	asm volatile(
-		"li $t1, 2\n"		/* index of first randomly-replaced entry */
+		"li $t1, 1\n"		/* index of first randomly-replaced entry */
 		"mtc0 $t1, $6\n"	/* CP0_WIRED */
 		"mtc0 $zero, $4\n"	/* CP0_CONTEXT */
 		"mtc0 $zero, $10\n"	/* CP0_ENTRYHI */
@@ -186,10 +186,6 @@
 	/* Map the code, making it globally available. */
 
 	map_page_index(0x80000000, 0x00000000, 16 * 1024 * 1024, 0x1f, 0, 0);
-
-	/* Map the page tables. */
-
-	map_page_index(page_table_start, page_table_start, 64 * 1024, 0x1f, 0, 1);
 }
 
 void map_page_index(u32 virtual, u32 physical, u32 pagesize, u8 flags, u8 asid, u32 index)
diff -r 4502cd6c7254 -r d323b7b05424 stage2/cpu.h
--- a/stage2/cpu.h	Sat Feb 27 18:34:50 2016 +0100
+++ b/stage2/cpu.h	Sat Feb 27 19:20:32 2016 +0100
@@ -17,7 +17,7 @@
 void map_page_index(u32, u32, u32, u8, u8, u32);
 void unmap_page(u32, u32, u32, u8, u8);
 
-#define page_table_start 0x00040000
+#define page_table_start 0x80040000
 #define page_table_task_size 0x00008000
 #define page_table_task_size_log2 15
 
diff -r 4502cd6c7254 -r d323b7b05424 stage2/entry.S
--- a/stage2/entry.S	Sat Feb 27 18:34:50 2016 +0100
+++ b/stage2/entry.S	Sat Feb 27 19:20:32 2016 +0100
@@ -27,7 +27,7 @@
 
 /* NOTE: Duplicated from cpu.h. */
 
-#define page_table_start 0x00040000
+#define page_table_start 0x80040000
 #define page_table_task_size_log2 15
 
 _tlb_entry:
diff -r 4502cd6c7254 -r d323b7b05424 stage2/irq.c
--- a/stage2/irq.c	Sat Feb 27 18:34:50 2016 +0100
+++ b/stage2/irq.c	Sat Feb 27 19:20:32 2016 +0100
@@ -51,7 +51,7 @@
 u32 current_stack_pointer;
 extern u32 _got_copy_start;
 
-const u32 stack_start = 0x00080000;
+const u32 stack_start = 0x80080000;
 const u32 stack_size = 0x00002000;
 const u32 pagesize = 4 * 1024;
 const u32 framesize = 120; /* see the handlers */
@@ -89,7 +89,7 @@
 
 		/* Switch task. */
 
-		/* switch_task(); */
+		switch_task();
 
 		/* Clear interrupt status. */
 
@@ -116,15 +116,11 @@
 	physical memory, but at the same address in virtual memory.
 	*/
 
-	virtual = stack_start;
 	physical = stack_start + stack_size * task;
+	virtual = physical;
 
 	init_page_table(page_table_start, virtual - pagesize * 2, physical - pagesize * 2, pagesize, 0x1e, task);
 
-	/* Map the page for initialisation. */
-
-	map_page(physical, physical, pagesize, 0x1e, 0);
-
 	/*
 	Set the stack for the new task, initialising the global pointer and
 	return address.
diff -r 4502cd6c7254 -r d323b7b05424 stage2/stage2.c
--- a/stage2/stage2.c	Sat Feb 27 18:34:50 2016 +0100
+++ b/stage2/stage2.c	Sat Feb 27 19:20:32 2016 +0100
@@ -50,7 +50,6 @@
 
 	start_task(1);
 	start_task(2);
-	invoke_task(1);
 
 	/* Now, wait for the tasks to be selected as interrupts occur. */