[pxe] Switch back to real mode on exit

Signed-off-by: Michael Brown <mcb30@ipxe.org>

5 files changed, 126 insertions, 6 deletions

diff --git a/Makefile b/Makefile
index baf60e1..eb5fedb 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,7 @@ CC=gcc
 CFLAGS= -Wall -march=i486 -m32 -O1 -fomit-frame-pointer -fno-builtin \
 	-ffreestanding -fPIC $(SMP_FL) -fno-stack-protector 
 	
-OBJS= head.o reloc.o main.o test.o init.o lib.o patn.o screen_buffer.o \
+OBJS= head.o exit.o reloc.o main.o test.o init.o lib.o patn.o screen_buffer.o \
       config.o cpuid.o linuxbios.o pci.o memsize.o spd.o error.o dmi.o controller.o \
       smp.o vmem.o random.o
       
@@ -48,6 +48,9 @@ setup.s: setup.S config.h defs.h
 pxe.s: pxe.S config.h defs.h
 	$(CC) -E -traditional $< -o $@
 
+exit.s: exit.S config.h defs.h
+	$(CC) -E -traditional $< -o $@
+
 memtest.bin: memtest_shared.bin bootsect.o setup.o memtest.bin.lds
 	$(LD) -T memtest.bin.lds bootsect.o setup.o -b binary \
 	memtest_shared.bin -o memtest.bin
diff --git a/exit.S b/exit.S
new file mode 100644
index 0000000..23858da
--- /dev/null
+++ b/exit.S
@@ -0,0 +1,81 @@
+/*
+ *	exit.S		Copyright (C) 2012 Michael Brown <mcb30@ipxe.org>
+ *
+ */
+
+#include "defs.h"
+
+.text
+.code32
+.globl exit
+exit:
+	/* Exit status to %eax */
+	movl	4(%esp), %eax
+
+	/* Load IDT and GDT and switch to 16-bit code segment */
+	cli
+	lidt	idt_descr
+	lgdt	gdt_descr
+	ljmp	$REAL_CS, $(1f - LOW_TEST_ADR)
+1:
+	.code16
+	/* Load 16-bit limits for other segment registers */
+	movw	$REAL_DS, %bx
+	movw	%bx, %ds
+	movw	%bx, %es
+	movw	%bx, %fs
+	movw	%bx, %gs
+	movw	%bx, %ss
+	movl	$LOW_TEST_ADR, %esp
+
+	/* Switch to real mode */
+	movl	%cr0, %ebx
+	andb	$~0x01, %bl
+	movl	%ebx, %cr0
+	ljmp	$(LOW_TEST_ADR >> 4), $1f
+1:
+	/* Load real-mode segment registers */
+	xorw	%bx, %bx
+	movw	%bx, %ds
+	movw	%bx, %es
+	movw	%bx, %fs
+	movw	%bx, %gs
+	movw	%bx, %ss
+
+	/* Reenable interrupts */
+	sti
+
+	/* Perform a warm reset */
+	movw	$0x1234, %ax
+	movw	%ax, 0x472
+	movb	$0xfe, %al
+	outb	%al, $0x64
+
+	/* If reset failed, halt the CPU */
+	cli
+	hlt
+
+.align 16
+gdt:
+	/* Dummy */
+	.word	0,0,0,0
+	/* Unused */
+	.word	0,0,0,0
+	/* Unused */
+	.word	0,0,0,0
+	/* Unused */
+	.word	0,0,0,0
+	/* 16 bit real mode code segment */
+	.word	0xffff, ( LOW_TEST_ADR & 0xffff )
+	.word	( 0x9b00 | ( LOW_TEST_ADR >> 16 ) ), 0
+	/* 16 bit real mode data segment */
+	.word	0xffff, 0, 0x9300, 0
+gdt_end:
+gdt_descr:
+	.word	gdt_end - gdt - 1
+	.long	gdt
+
+.align 16
+idt_descr:
+	.word	0xffff
+	.long	0
diff --git a/lib.c b/lib.c
index a2b829d..299a2d7 100644
--- a/lib.c
+++ b/lib.c
@@ -28,6 +28,9 @@ int serial_baud_rate = SERIAL_BAUD_RATE;
 unsigned char serial_parity = 0;
 unsigned char serial_bits = 8;
 
+extern volatile int mstr_cpu;
+extern volatile int bail;
+
 struct ascii_map_str {
         int ascii;
         int keycode;
@@ -632,7 +635,8 @@ void check_input(void)
 		case 1:	
 			/* "ESC" key was pressed, bail out.  */
 			cprint(LINE_RANGE, COL_MID+23, "Halting... ");
-			reboot();
+			v->exit++;
+			bail++;
 			break;
 		case 46:
 			/* c - Configure */
@@ -1196,4 +1200,4 @@ void get_list(int x, int y, int len, char *buf)
 		   return;
 		}
 	}
-}
\ No newline at end of file
+}
diff --git a/main.c b/main.c
index 144fb1b..bf456ef 100644
--- a/main.c
+++ b/main.c
@@ -203,7 +203,7 @@ void btrace(int me, int line, char *msg, int wait, long v1, long v2)
 }
 
 /* Relocate the test to a new address. Be careful to not overlap! */
-static void run_at(unsigned long addr, int cpu)
+void run_at(unsigned long addr, int cpu)
 {
 	ulong *ja = (ulong *)(addr + startup_32 - _start);
 
@@ -526,6 +526,25 @@ void test_start(void)
 	btrace(my_cpu_num, __LINE__, "Start Done", 1, 0, 0);
 	start_seq = 2;
 
+	/* Exit if testing has finished */
+	if (v->exit) {
+		paging_off();
+		set_cache(1);
+		barrier();
+		if (my_cpu_num == 0) {
+			if (v->ecount) {
+				exit(EXIT_FAILURE);
+			} else if (v->pass) {
+				exit(EXIT_SUCCESS);
+			} else {
+				exit(EXIT_INCOMPLETE);
+			}
+		} else {
+			/* Halt APs */
+			__asm__ __volatile__ ( "cli ; hlt" );
+		}
+	}
+
 	/* Loop through all tests */
 	while (1) {
 	    /* If the restart flag is set all initial params */
@@ -550,6 +569,11 @@ void test_start(void)
 		btrace(my_cpu_num, __LINE__, "Sched_Barr", 1,window,win_next);
 		barrier();
 
+		/* Exit if testing has finished */
+		if (v->exit) {
+			run_at(LOW_TEST_ADR, my_cpu_num);
+		}
+
 		/* Don't go over the 8TB PAE limit */
 		if (win_next > MAX_MEM) {
 			break;
@@ -759,8 +783,8 @@ void test_start(void)
 			if (v->ecount == 0) 
 				{
 			    /* If onepass is enabled and we did not get any errors
-			     * reboot to exit the test */
-			    if (onepass) {	reboot();   }
+			     * exit the test */
+			    if (onepass) { v->exit++; }
 			    if (!btflag) cprint(LINE_MSG, COL_MSG-8, "** Pass complete, no errors, press Esc to exit **");
 					if(BEEP_END_NO_ERROR) 
 						{
diff --git a/test.h b/test.h
index 862da15..4a7e375 100644
--- a/test.h
+++ b/test.h
@@ -173,6 +173,7 @@ int get_key(void);
 int ascii_to_keycode(int in);
 void wait_keyup(void);
 void print_hdr(void);
+void run_at(unsigned long addr, int cpu);
 void restart(void);
 void parity_err(ulong edi, ulong esi);
 void start_config(void);
@@ -190,6 +191,7 @@ void bit_fade_fill(unsigned long n, int cpu);
 void bit_fade_chk(unsigned long n, int cpu);
 void find_ticks_for_pass(void);
 void beep(unsigned int frequency);
+void exit(int status);
 
 #define PRINTMODE_SUMMARY   0
 #define PRINTMODE_ADDRESSES 1
@@ -302,6 +304,7 @@ struct vars {
 	int fail_safe;
 	int each_sec;
 	int beepmode;
+	int exit;
 };
 
 #define FIRMWARE_UNKNOWN   0
@@ -314,5 +317,10 @@ extern unsigned char _size, _pages;
 
 extern struct mem_info_t mem_info;
 
+/* Exit codes */
+#define EXIT_SUCCESS 0
+#define EXIT_FAILURE 1
+#define EXIT_INCOMPLETE 2
+
 #endif /* __ASSEMBLY__ */
 #endif /* _TEST_H_ */