Applied patch by "Grey":

Entering the boot loader menu has changed/simplified while reducing the boot time by .75 seconds.
Now it is enough to hold one of shift/Esc/F8/F12/Space. Thanks!

I've also updated the boot loader documentation to reflect the change, but I only mentioned holding shift.
I know that changing the documention directly is not preferred anymore, but I wanted to make sure this
patch is complete.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35050 a95241bf-73f2-0310-859d-f6bbb57e9c96

docs/userguide/en/bootloader.html

@@ -40,7 +40,7 @@
 
 <p>Haiku's Boot Loader can help when you experience hardware related problems or want to choose which Haiku installation to start, if you have more than one (maybe on an installation CD or USB stick).<br />
 It's also handy after you installed a software component that acts up and prevents you from booting the system to remove it again. The <i>Disable user add-ons</i> option that's mentioned below, will start Haiku without loading user installed components, e.g. a driver.</p>
-<p>To enter the Boot Loader options, you have to press the <span class="key">SPACE BAR</span> right at the beginning of the boot process. It's easy to miss so you best keep hitting the key until it shows up.</p>
+<p>To enter the Boot Loader options, you have to press and keep holding the <span class="key">SHIFT</span> key before the beginning of Haiku's boot process. If you have a boot manager installed, you can start holding the <span class="key">SHIFT</span> key before invoking the boot entry for Haiku. If Haiku is the only operating system installed, you can start pressing <span class="key">SHIFT</span> while you still see boot messages from the BIOS.</p>
 <p><br /></p>
 <p>Once it's there, you're offered three menus:</p>
 <table summary="bootloader menus" border="0" cellspacing="0" cellpadding="2">

src/system/boot/platform/bios_ia32/bios.S

@@ -22,6 +22,7 @@
 #define SAVED_EAX		0x10008
 #define SAVED_ES		0x1000c
 #define SAVED_FLAGS		0x10010
+#define SAVED_EBP		0x10014
 	// we're overwriting the start of our boot loader to hold some
 	// temporary values - the first 1024 bytes of it are used at
 	// startup only, and we avoid some linking issues this way
@@ -74,7 +75,7 @@ _no_paging:
 	// setup protected stack frame again
 	movl	SAVED_ESP, %eax
 	movl	%eax, %esp
-	movl	%eax, %ebp
+	movl	SAVED_EBP, %ebp
 
 	// copy the return address to the current stack
 	movl	REAL_MODE_STACK, %eax
@@ -96,6 +97,8 @@ FUNCTION(switch_to_real_mode)
 	movl	%esp, %eax
 	movl	%eax, SAVED_ESP
 
+	movl	%ebp, SAVED_EBP
+
 	// put the return address on the real mode stack
 	movl	(%esp), %eax
 	movl	%eax, REAL_MODE_STACK
@@ -232,6 +235,63 @@ int_number:
 
 //--------------------------------------------------------------
 
+/** uint32  search_keyboard_buffer()
+ *  Search in keyboard buffer keycodes for F8, F12 or Space 
+ *  if not found - search ESC keycode.
+ */
+
+FUNCTION(search_keyboard_buffer)
+	pushal
+	pushfl
+
+	// make sure the correct IDT is in place
+	lidt 	idt_descriptor
+
+	call	switch_to_real_mode
+	.code16
+
+	cld
+	push	%ds
+	xorl	%eax, %eax
+	mov	%ax, %ds
+	mov	$0x41E, %si	// BIOS kbd buffer
+search_cycle1:
+	lodsw
+	cmp	$0x4200, %ax	// test F8 key
+	jz	to_ret
+	cmp	$0x8600, %ax	// test F12 key
+	jz	to_ret
+	cmp	$0x3920, %ax	// test Space key
+	jz	to_ret
+	cmp	$0x440, %si
+	jnz	search_cycle1
+
+	movw	$0x41E, %si	// BIOS kbd buffer
+search_cycle2:
+	lodsw
+	cmp	$0x011B, %ax	// test ESC key
+	jz	to_ret
+	cmp	$0x440, %si
+	jnz	search_cycle2
+to_ret:
+	pop	%ds
+
+	// save %eax
+	movl	%eax, (SAVED_EAX - 0x10000)
+
+	call	switch_to_protected_mode
+	.code32
+
+	popfl
+	popal
+
+	// restore %eax
+	movl	SAVED_EAX, %eax
+
+	ret
+
+//--------------------------------------------------------------
+
 .globl idt_descriptor
 idt_descriptor:
 	.short	0x7ff				// IDT at 0x0, default real mode location

src/system/boot/platform/bios_ia32/bios.h

@@ -41,5 +41,10 @@ extern
 "C"
 #endif
 void call_bios(uint8 num, struct bios_regs *regs);
+extern
+#ifdef __cplusplus
+"C"
+#endif
+uint32 search_keyboard_buffer();
 
 #endif	/* BIOS_H */

src/system/boot/platform/bios_ia32/keyboard.cpp

@@ -58,22 +58,24 @@ wait_for_key(void)
 extern "C" uint32
 check_for_boot_keys(void)
 {
-	union key key;
+	bios_regs regs;
 	uint32 options = 0;
-
+	uint32 keycode = 0;
-	while ((key.ax = check_for_key()) != 0) {
+	regs.eax = 0x0200;
-		switch (key.code.ascii) {
+	call_bios(0x16, &regs);
-			case ' ':
+		// Read Keyboard flags. bit 0 LShift, bit 1 RShift
-				options |= BOOT_OPTION_MENU;
+	if ((regs.eax & 0x03) != 0) {
-				break;
+		// LShift or RShift - option menu
-			case 0x1b:	// escape
+		options |= BOOT_OPTION_MENU;
-				options |= BOOT_OPTION_DEBUG_OUTPUT;
+	} else {
-				break;
+		keycode = search_keyboard_buffer();
-			case 0:
+		if (keycode == 0x4200 || keycode == 0x8600 || keycode == 0x3920) {
-				// evaluate BIOS scan codes
+			// F8 or F12 or Space - option menu
-				// ...
+			options |= BOOT_OPTION_MENU;
-				break;
+		} else if (keycode == 0x011B) {
-		}
+			// ESC - debug output
+			options |= BOOT_OPTION_DEBUG_OUTPUT;
+ 		}
 	}
 
 	dprintf("options = %ld\n", options);

src/system/boot/platform/bios_ia32/start.c

@@ -129,9 +129,6 @@ _start(void)
 	mmu_init();
 	parse_multiboot_commandline(&args);
 
-	// wait a bit to give the user the opportunity to press a key
-	spin(750000);
-
 	// reading the keyboard doesn't seem to work in graphics mode
 	// (maybe a bochs problem)
 	sBootOptions = check_for_boot_keys();