Patchwork fix linuxboot.bin and multiboot.bin to not hijack int19

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Submitter Gleb Natapov
Date Jan. 31, 2011, 9:02 a.m.
Message ID <20110131090247.GT14750@redhat.com>
Download mbox | patch
Permalink /patch/81087/
State New
Headers show

Comments

Gleb Natapov - Jan. 31, 2011, 9:02 a.m.
Currently linuxboot.bin and multiboot.bin option roms override int19
vector to intercept boot process. No sane option rom should do that.
Provide bev entry instead that will be called by BIOS if option rom
is selected for booting.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
---

Note that this patch should be applied after qemu will upgrade to Seabios
that supports boot order. Otherwise there will be change in behavior
since option rom will not be selected for booting by default.

--
			Gleb.
Alexander Graf - Jan. 31, 2011, 11:41 a.m.
On 31.01.2011, at 10:02, Gleb Natapov wrote:

> Currently linuxboot.bin and multiboot.bin option roms override int19
> vector to intercept boot process. No sane option rom should do that.
> Provide bev entry instead that will be called by BIOS if option rom
> is selected for booting.
> 
> Signed-off-by: Gleb Natapov <gleb@redhat.com>
> ---
> 
> Note that this patch should be applied after qemu will upgrade to Seabios
> that supports boot order. Otherwise there will be change in behavior
> since option rom will not be selected for booting by default.
> 
> diff --git a/pc-bios/optionrom/linuxboot.S b/pc-bios/optionrom/linuxboot.S
> index c109363..79b3ae8 100644
> --- a/pc-bios/optionrom/linuxboot.S
> +++ b/pc-bios/optionrom/linuxboot.S
> @@ -22,6 +22,8 @@
> 
> #include "optionrom.h"
> 
> +#define PRODUCT "Linux loader"
> +
> BOOT_ROM_START
> 
> run_linuxboot:
> diff --git a/pc-bios/optionrom/multiboot.S b/pc-bios/optionrom/multiboot.S
> index 9131837..069c4e8 100644
> --- a/pc-bios/optionrom/multiboot.S
> +++ b/pc-bios/optionrom/multiboot.S
> @@ -20,6 +20,8 @@
> 
> #include "optionrom.h"
> 
> +#define PRODUCT "multiboot loader"
> +
> #define MULTIBOOT_MAGIC		0x2badb002
> 
> #define GS_PROT_JUMP		0
> diff --git a/pc-bios/optionrom/optionrom.h b/pc-bios/optionrom/optionrom.h
> index fbdd48a..95dbdda 100644
> --- a/pc-bios/optionrom/optionrom.h
> +++ b/pc-bios/optionrom/optionrom.h
> @@ -93,31 +93,41 @@
> 	.global 	_start;				\
>     _start:;						\
> 	.short		0xaa55;				\
> -	.byte		(_end - _start) / 512;
> +	.byte		(_end - _start) / 512;		\
> +	lret;						\
> +	.org 		0x18;				\
> +	.short		0;				\
> +	.short		_pnph;				\
> +    _pnph:						\
> +	.ascii		"$PnP";				\

The idea behind the OPTION_ROM and BOOT_ROM split was to have a generic header that can be used as template for random option roms or boot roms alike. Your patch munges those two use-cases together by providing bev logic in the generic option rom part.

Please split it out into the BOOT_ROM macro, or - if necessary - create a new macro.


Alex
Anthony Liguori - Feb. 1, 2011, 11:02 p.m.
On 01/31/2011 03:02 AM, Gleb Natapov wrote:
> Currently linuxboot.bin and multiboot.bin option roms override int19
> vector to intercept boot process. No sane option rom should do that.
> Provide bev entry instead that will be called by BIOS if option rom
> is selected for booting.
>
> Signed-off-by: Gleb Natapov<gleb@redhat.com>
> ---
>
> Note that this patch should be applied after qemu will upgrade to Seabios
> that supports boot order. Otherwise there will be change in behavior
> since option rom will not be selected for booting by default.
>    

I don't think there's a SeaBIOS release yet that includes the boot order 
support.

Regards,

Anthony Liguori

> diff --git a/pc-bios/optionrom/linuxboot.S b/pc-bios/optionrom/linuxboot.S
> index c109363..79b3ae8 100644
> --- a/pc-bios/optionrom/linuxboot.S
> +++ b/pc-bios/optionrom/linuxboot.S
> @@ -22,6 +22,8 @@
>
>   #include "optionrom.h"
>
> +#define PRODUCT "Linux loader"
> +
>   BOOT_ROM_START
>
>   run_linuxboot:
> diff --git a/pc-bios/optionrom/multiboot.S b/pc-bios/optionrom/multiboot.S
> index 9131837..069c4e8 100644
> --- a/pc-bios/optionrom/multiboot.S
> +++ b/pc-bios/optionrom/multiboot.S
> @@ -20,6 +20,8 @@
>
>   #include "optionrom.h"
>
> +#define PRODUCT "multiboot loader"
> +
>   #define MULTIBOOT_MAGIC		0x2badb002
>
>   #define GS_PROT_JUMP		0
> diff --git a/pc-bios/optionrom/optionrom.h b/pc-bios/optionrom/optionrom.h
> index fbdd48a..95dbdda 100644
> --- a/pc-bios/optionrom/optionrom.h
> +++ b/pc-bios/optionrom/optionrom.h
> @@ -93,31 +93,41 @@
>   	.global 	_start;				\
>       _start:;						\
>   	.short		0xaa55;				\
> -	.byte		(_end - _start) / 512;
> +	.byte		(_end - _start) / 512;		\
> +	lret;						\
> +	.org 		0x18;				\
> +	.short		0;				\
> +	.short		_pnph;				\
> +    _pnph:						\
> +	.ascii		"$PnP";				\
> +	.byte		0x01;				\
> +	.byte		( _pnph_len / 16 );		\
> +	.short		0x0000;				\
> +	.byte		0x00;				\
> +	.byte		0x00;				\
> +	.long		0x00000000;			\
> +	.short		_manufacturer;			\
> +	.short		_product;			\
> +	.long		0x00000000;			\
> +	.short		0x0000;				\
> +	.short		0x0000;				\
> +	.short		_bev;				\
> +	.short		0x0000;				\
> +	.short		0x0000;				\
> +	.equ		_pnph_len, . - _pnph;
>
>   #define BOOT_ROM_START					\
>   	OPTION_ROM_START				\
> -	push		%eax;				\
> -	push		%ds;				\
> -							\
> -	/* setup ds so we can access the IVT */		\
> -	xor		%ax, %ax;			\
> -	mov		%ax, %ds;			\
> -							\
> -	/* install our int 19 handler */		\
> -	movw		$int19_handler, (0x19*4);	\
> -	mov		%cs, (0x19*4+2);		\
> -							\
> -	pop		%ds;				\
> -	pop		%eax;				\
> -	lret;						\
> -							\
> -    int19_handler:;					\
> +    _bev:;						\
>   	/* DS = CS */					\
>   	movw		%cs, %ax;			\
>   	movw		%ax, %ds;
>
>   #define OPTION_ROM_END					\
> +    _manufacturer:;					\
> +        .asciz "QEMU";					\
> +    _product:;						\
> +        .asciz PRODUCT;					\
>       .align 512, 0;					\
>       _end:
>
> --
> 			Gleb.
>
>
Gleb Natapov - Feb. 2, 2011, 5:06 a.m.
On Tue, Feb 01, 2011 at 05:02:55PM -0600, Anthony Liguori wrote:
> On 01/31/2011 03:02 AM, Gleb Natapov wrote:
> >Currently linuxboot.bin and multiboot.bin option roms override int19
> >vector to intercept boot process. No sane option rom should do that.
> >Provide bev entry instead that will be called by BIOS if option rom
> >is selected for booting.
> >
> >Signed-off-by: Gleb Natapov<gleb@redhat.com>
> >---
> >
> >Note that this patch should be applied after qemu will upgrade to Seabios
> >that supports boot order. Otherwise there will be change in behavior
> >since option rom will not be selected for booting by default.
> 
> I don't think there's a SeaBIOS release yet that includes the boot
> order support.
> 
I thought for AHCI support you are going to move to latest Seabios HEAD.
If this is not the case the patch should wait.

> Regards,
> 
> Anthony Liguori
> 
> >diff --git a/pc-bios/optionrom/linuxboot.S b/pc-bios/optionrom/linuxboot.S
> >index c109363..79b3ae8 100644
> >--- a/pc-bios/optionrom/linuxboot.S
> >+++ b/pc-bios/optionrom/linuxboot.S
> >@@ -22,6 +22,8 @@
> >
> >  #include "optionrom.h"
> >
> >+#define PRODUCT "Linux loader"
> >+
> >  BOOT_ROM_START
> >
> >  run_linuxboot:
> >diff --git a/pc-bios/optionrom/multiboot.S b/pc-bios/optionrom/multiboot.S
> >index 9131837..069c4e8 100644
> >--- a/pc-bios/optionrom/multiboot.S
> >+++ b/pc-bios/optionrom/multiboot.S
> >@@ -20,6 +20,8 @@
> >
> >  #include "optionrom.h"
> >
> >+#define PRODUCT "multiboot loader"
> >+
> >  #define MULTIBOOT_MAGIC		0x2badb002
> >
> >  #define GS_PROT_JUMP		0
> >diff --git a/pc-bios/optionrom/optionrom.h b/pc-bios/optionrom/optionrom.h
> >index fbdd48a..95dbdda 100644
> >--- a/pc-bios/optionrom/optionrom.h
> >+++ b/pc-bios/optionrom/optionrom.h
> >@@ -93,31 +93,41 @@
> >  	.global 	_start;				\
> >      _start:;						\
> >  	.short		0xaa55;				\
> >-	.byte		(_end - _start) / 512;
> >+	.byte		(_end - _start) / 512;		\
> >+	lret;						\
> >+	.org 		0x18;				\
> >+	.short		0;				\
> >+	.short		_pnph;				\
> >+    _pnph:						\
> >+	.ascii		"$PnP";				\
> >+	.byte		0x01;				\
> >+	.byte		( _pnph_len / 16 );		\
> >+	.short		0x0000;				\
> >+	.byte		0x00;				\
> >+	.byte		0x00;				\
> >+	.long		0x00000000;			\
> >+	.short		_manufacturer;			\
> >+	.short		_product;			\
> >+	.long		0x00000000;			\
> >+	.short		0x0000;				\
> >+	.short		0x0000;				\
> >+	.short		_bev;				\
> >+	.short		0x0000;				\
> >+	.short		0x0000;				\
> >+	.equ		_pnph_len, . - _pnph;
> >
> >  #define BOOT_ROM_START					\
> >  	OPTION_ROM_START				\
> >-	push		%eax;				\
> >-	push		%ds;				\
> >-							\
> >-	/* setup ds so we can access the IVT */		\
> >-	xor		%ax, %ax;			\
> >-	mov		%ax, %ds;			\
> >-							\
> >-	/* install our int 19 handler */		\
> >-	movw		$int19_handler, (0x19*4);	\
> >-	mov		%cs, (0x19*4+2);		\
> >-							\
> >-	pop		%ds;				\
> >-	pop		%eax;				\
> >-	lret;						\
> >-							\
> >-    int19_handler:;					\
> >+    _bev:;						\
> >  	/* DS = CS */					\
> >  	movw		%cs, %ax;			\
> >  	movw		%ax, %ds;
> >
> >  #define OPTION_ROM_END					\
> >+    _manufacturer:;					\
> >+        .asciz "QEMU";					\
> >+    _product:;						\
> >+        .asciz PRODUCT;					\
> >      .align 512, 0;					\
> >      _end:
> >
> >--
> >			Gleb.
> >

--
			Gleb.

Patch

diff --git a/pc-bios/optionrom/linuxboot.S b/pc-bios/optionrom/linuxboot.S
index c109363..79b3ae8 100644
--- a/pc-bios/optionrom/linuxboot.S
+++ b/pc-bios/optionrom/linuxboot.S
@@ -22,6 +22,8 @@ 
 
 #include "optionrom.h"
 
+#define PRODUCT "Linux loader"
+
 BOOT_ROM_START
 
 run_linuxboot:
diff --git a/pc-bios/optionrom/multiboot.S b/pc-bios/optionrom/multiboot.S
index 9131837..069c4e8 100644
--- a/pc-bios/optionrom/multiboot.S
+++ b/pc-bios/optionrom/multiboot.S
@@ -20,6 +20,8 @@ 
 
 #include "optionrom.h"
 
+#define PRODUCT "multiboot loader"
+
 #define MULTIBOOT_MAGIC		0x2badb002
 
 #define GS_PROT_JUMP		0
diff --git a/pc-bios/optionrom/optionrom.h b/pc-bios/optionrom/optionrom.h
index fbdd48a..95dbdda 100644
--- a/pc-bios/optionrom/optionrom.h
+++ b/pc-bios/optionrom/optionrom.h
@@ -93,31 +93,41 @@ 
 	.global 	_start;				\
     _start:;						\
 	.short		0xaa55;				\
-	.byte		(_end - _start) / 512;
+	.byte		(_end - _start) / 512;		\
+	lret;						\
+	.org 		0x18;				\
+	.short		0;				\
+	.short		_pnph;				\
+    _pnph:						\
+	.ascii		"$PnP";				\
+	.byte		0x01;				\
+	.byte		( _pnph_len / 16 );		\
+	.short		0x0000;				\
+	.byte		0x00;				\
+	.byte		0x00;				\
+	.long		0x00000000;			\
+	.short		_manufacturer;			\
+	.short		_product;			\
+	.long		0x00000000;			\
+	.short		0x0000;				\
+	.short		0x0000;				\
+	.short		_bev;				\
+	.short		0x0000;				\
+	.short		0x0000;				\
+	.equ		_pnph_len, . - _pnph;
 
 #define BOOT_ROM_START					\
 	OPTION_ROM_START				\
-	push		%eax;				\
-	push		%ds;				\
-							\
-	/* setup ds so we can access the IVT */		\
-	xor		%ax, %ax;			\
-	mov		%ax, %ds;			\
-							\
-	/* install our int 19 handler */		\
-	movw		$int19_handler, (0x19*4);	\
-	mov		%cs, (0x19*4+2);		\
-							\
-	pop		%ds;				\
-	pop		%eax;				\
-	lret;						\
-							\
-    int19_handler:;					\
+    _bev:;						\
 	/* DS = CS */					\
 	movw		%cs, %ax;			\
 	movw		%ax, %ds;
 
 #define OPTION_ROM_END					\
+    _manufacturer:;					\
+        .asciz "QEMU";					\
+    _product:;						\
+        .asciz PRODUCT;					\
     .align 512, 0;					\
     _end: