# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1462443564 -7200
# Node ID 739db6eca61a4a7f7462318fae8b74c10dfb83ac
# Parent  174153b3fcbc9ec2775d5f29a52e74ec868caffa
Permit entry into user mode by avoiding calling udelay which needs access to a
timer in a privileged address space.

diff -r 174153b3fcbc -r 739db6eca61a stage2/cpu_op.S
--- a/stage2/cpu_op.S	Wed May 04 23:59:04 2016 +0200
+++ b/stage2/cpu_op.S	Thu May 05 12:19:24 2016 +0200
@@ -35,6 +35,7 @@
 .globl enable_interrupts
 .globl init_interrupts
 .globl invoke_task
+.globl enter_task
 .globl configure_tlb
 .globl map_page_set_index
 .globl map_page_index_op
@@ -126,8 +127,10 @@
 	lw $t9, 100($t3)
 	lw $gp, 104($t3)
 	mtc0 $t9, CP0_EPC
+
+enter_task:
 	mfc0 $t3, CP0_STATUS
-	ori $t3, $t3, STATUS_EXL
+	ori $t3, $t3, STATUS_EXL | STATUS_UM
 	mtc0 $t3, CP0_STATUS
 	eret
 	nop
diff -r 174153b3fcbc -r 739db6eca61a stage2/example.c
--- a/stage2/example.c	Wed May 04 23:59:04 2016 +0200
+++ b/stage2/example.c	Thu May 05 12:19:24 2016 +0200
@@ -55,10 +55,12 @@
 
 void plot_pattern(unsigned short pixel_type, unsigned short x, unsigned short y)
 {
+	int i;
+
 	while (1) {
 		test_pixel(x, y, pixel_type);
 		next_pixel(&x, &y);
-		udelay(100);
+		for (i = 0; i < 10000; i++);
 	}
 }
 
diff -r 174153b3fcbc -r 739db6eca61a stage2/handlers.S
--- a/stage2/handlers.S	Wed May 04 23:59:04 2016 +0200
+++ b/stage2/handlers.S	Thu May 05 12:19:24 2016 +0200
@@ -25,8 +25,8 @@
 .extern current_registers
 .extern current_stack_pointer
 .extern current_task
+.extern enter_task
 .globl interrupt_handler
-.globl enter_task
 .set noreorder
 .set noat
 
@@ -150,8 +150,7 @@
 	lw $k0, 124($k1)
 	mthi $k0
 
-enter_task:
-	eret
+	j enter_task
 	nop
 
 .set reorder