[haiku-bugs] Re: [Haiku] #5113: [PATCH] Warm boot for Bootloader
- From: "axeld" <trac@xxxxxxxxxxxx>
- Date: Sat, 12 Dec 2009 17:54:28 -0000
#5113: [PATCH] Warm boot for Bootloader
--------------------------------+-------------------------------------------
Reporter: Grey | Owner: axeld
Type: enhancement | Status: new
Priority: normal | Milestone: R1
Component: System/Boot Loader | Version: R1/alpha1
Keywords: Warm boot | Blockedby:
Platform: x86 | Blocking:
--------------------------------+-------------------------------------------
Old description:
> This is small patch for bootloader. X86 only!
> Function war_boot() added to src/system/boot/platform/bios_ia32/bios.S
> Press 'W' or 'w' for warm boot.
>
> Index: src/system/boot/platform/bios_ia32/keyboard.h
> ===================================================================
> --- src/system/boot/platform/bios_ia32/keyboard.h (revision 34640)
> +++ src/system/boot/platform/bios_ia32/keyboard.h (working copy)
> @@ -29,6 +29,7 @@
> extern void clear_key_buffer(void);
> extern union key wait_for_key(void);
> extern uint32 check_for_boot_keys(void);
> +extern void warm_boot(void);
>
> #ifdef __cplusplus
> }
> Index: src/system/boot/platform/bios_ia32/bios.S
> ===================================================================
> --- src/system/boot/platform/bios_ia32/bios.S (revision 34640)
> +++ src/system/boot/platform/bios_ia32/bios.S (working copy)
> @@ -231,7 +231,49 @@
> ret
>
> //--------------------------------------------------------------
> +/** void warm_boot()
> + * Warm booting computer via BIOS int 0x19. save_crx() have to be
> called before paging setup.
> + */
> +FUNCTION(warm_boot)
> + cli
> + movl saved_cr0,%eax
> + movl %eax,%cr0
> + movl saved_cr3,%eax
> + movl %eax,%cr3
> + movl saved_cr4,%eax
> + movl %eax,%cr4
> + lidt saved_idt
> + call switch_to_real_mode
> + .byte 0xCD
> + .byte 0x19
> + ret
> +//--------------------------------------------------------------
> +/** void save_crx()
> + * Save CRx registers state. Required for warm_boot.
> + */
> +FUNCTION(save_crx)
> + cli
> + movl %cr0,%eax
> + movl %eax,saved_cr0
> + movl %cr3,%eax
> + movl %eax,saved_cr3
> + movl %cr4,%eax
> + movl %eax,saved_cr4
> + sidt saved_idt
> + ret
> +//--------------------------------------------------------------
> + .p2align 4
> +saved_idt:
> + .long 0x0
> + .long 0x0
> +saved_cr0:
> + .long 0x0
> +saved_cr3:
> + .long 0x0
> +saved_cr4:
> + .long 0x0
>
> + .p2align 4
> .globl idt_descriptor
> idt_descriptor:
> .short 0x7ff // IDT at 0x0, default
> real mode location
> Index: src/system/boot/platform/bios_ia32/keyboard.cpp
> ===================================================================
> --- src/system/boot/platform/bios_ia32/keyboard.cpp (revision 34640)
> +++ src/system/boot/platform/bios_ia32/keyboard.cpp (working copy)
> @@ -69,6 +69,9 @@
> case 0x1b: // escape
> options |= BOOT_OPTION_DEBUG_OUTPUT;
> break;
> + case 'w':
> + case 'W':
> + warm_boot();
> case 0:
> // evaluate BIOS scan codes
> // ...
> Index: src/system/boot/platform/bios_ia32/start.c
> ===================================================================
> --- src/system/boot/platform/bios_ia32/start.c (revision 34640)
> +++ src/system/boot/platform/bios_ia32/start.c (working copy)
> @@ -107,7 +107,6 @@
> out8(0xfe, 0x64);
> }
>
> -
> void
> _start(void)
> {
> @@ -126,6 +125,7 @@
> serial_init();
> console_init();
> cpu_init();
> + save_crx();
> mmu_init();
> parse_multiboot_commandline(&args);
New description:
This is small patch for bootloader. X86 only!
Function war_boot() added to src/system/boot/platform/bios_ia32/bios.S
Press 'W' or 'w' for warm boot.
{{{
Index: src/system/boot/platform/bios_ia32/keyboard.h
===================================================================
--- src/system/boot/platform/bios_ia32/keyboard.h (revision 34640)
+++ src/system/boot/platform/bios_ia32/keyboard.h (working copy)
@@ -29,6 +29,7 @@
extern void clear_key_buffer(void);
extern union key wait_for_key(void);
extern uint32 check_for_boot_keys(void);
+extern void warm_boot(void);
#ifdef __cplusplus
}
Index: src/system/boot/platform/bios_ia32/bios.S
===================================================================
--- src/system/boot/platform/bios_ia32/bios.S (revision 34640)
+++ src/system/boot/platform/bios_ia32/bios.S (working copy)
@@ -231,7 +231,49 @@
ret
//--------------------------------------------------------------
+/** void warm_boot()
+ * Warm booting computer via BIOS int 0x19. save_crx() have to be
called before paging setup.
+ */
+FUNCTION(warm_boot)
+ cli
+ movl saved_cr0,%eax
+ movl %eax,%cr0
+ movl saved_cr3,%eax
+ movl %eax,%cr3
+ movl saved_cr4,%eax
+ movl %eax,%cr4
+ lidt saved_idt
+ call switch_to_real_mode
+ .byte 0xCD
+ .byte 0x19
+ ret
+//--------------------------------------------------------------
+/** void save_crx()
+ * Save CRx registers state. Required for warm_boot.
+ */
+FUNCTION(save_crx)
+ cli
+ movl %cr0,%eax
+ movl %eax,saved_cr0
+ movl %cr3,%eax
+ movl %eax,saved_cr3
+ movl %cr4,%eax
+ movl %eax,saved_cr4
+ sidt saved_idt
+ ret
+//--------------------------------------------------------------
+ .p2align 4
+saved_idt:
+ .long 0x0
+ .long 0x0
+saved_cr0:
+ .long 0x0
+saved_cr3:
+ .long 0x0
+saved_cr4:
+ .long 0x0
+ .p2align 4
.globl idt_descriptor
idt_descriptor:
.short 0x7ff // IDT at 0x0, default
real mode location
Index: src/system/boot/platform/bios_ia32/keyboard.cpp
===================================================================
--- src/system/boot/platform/bios_ia32/keyboard.cpp (revision 34640)
+++ src/system/boot/platform/bios_ia32/keyboard.cpp (working copy)
@@ -69,6 +69,9 @@
case 0x1b: // escape
options |= BOOT_OPTION_DEBUG_OUTPUT;
break;
+ case 'w':
+ case 'W':
+ warm_boot();
case 0:
// evaluate BIOS scan codes
// ...
Index: src/system/boot/platform/bios_ia32/start.c
===================================================================
--- src/system/boot/platform/bios_ia32/start.c (revision 34640)
+++ src/system/boot/platform/bios_ia32/start.c (working copy)
@@ -107,7 +107,6 @@
out8(0xfe, 0x64);
}
-
void
_start(void)
{
@@ -126,6 +125,7 @@
serial_init();
console_init();
cpu_init();
+ save_crx();
mmu_init();
parse_multiboot_commandline(&args);
}}}
--
Comment(by axeld):
First of all thanks for the patch.
But then, please attach a diff instead of of copying it into the ticket
description next time.
Also, changes like:
{{{
}
-
void
_start(void)
}}}
shouldn't be found in such a patch, as this introduces a style violation
in previously fine code.
Then:
{{{
+ case 'w':
+ case 'W':
+ warm_boot();
case 0:
}}}
There is a "break;" missing - even if warm_boot() is not supposed to
return, it's just good style.
Finally, what is the purpose of this patch? What does it do, and what does
one gain?
--
Ticket URL: <http://dev.haiku-os.org/ticket/5113#comment:1>
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