Re: [PATCH -mm -v3 1/2] i386/x86_64 boot: setup data
Huang, Ying wrote: > Hi, Peter, > > On Wed, 2007-09-19 at 09:04 -0700, H. Peter Anvin wrote: >> Huang, Ying wrote: >>> Known Issues: >>> >>> 1. Where is safe to place the linked list of setup_data? >>> Because the length of the linked list of setup_data is variable, it >>> can not be copied into BSS segment of kernel as that of "zero >>> page". We must find a safe place for it, where it will not be >>> overwritten by kernel during booting up. The i386 kernel will >>> overwrite some pages after _end. The x86_64 kernel will overwrite some >>> pages from 0x1000 on. >>> >> The latter is definitely not safe, since the space below 640K is the >> documented place to put the command line (and presumably where the >> bootloader would put other auxilliary chunks.) >> >> I'll try to do a full review of this later today. Haven't had time yet >> to look at this anything than but piecemeal. > > Do you think this patch and the 32-bit boot protocol patch are ready to > merge for -mm? If not, I can revise them. > Sorry, haven't had a chance to look at it in proper detail yet, mostly due to debugging, but one thing I'd like to see is both the boot_params structure as well as all the chained information pointers exported into sysfs. The experience with the x86 setup code has shown that it would help immensely with debugging, not to mention being available to tools like kexec. -hpa - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm -v3 1/2] i386/x86_64 boot: setup data
Hi, Peter, On Wed, 2007-09-19 at 09:04 -0700, H. Peter Anvin wrote: > Huang, Ying wrote: > > > > Known Issues: > > > > 1. Where is safe to place the linked list of setup_data? > > Because the length of the linked list of setup_data is variable, it > > can not be copied into BSS segment of kernel as that of "zero > > page". We must find a safe place for it, where it will not be > > overwritten by kernel during booting up. The i386 kernel will > > overwrite some pages after _end. The x86_64 kernel will overwrite some > > pages from 0x1000 on. > > > > The latter is definitely not safe, since the space below 640K is the > documented place to put the command line (and presumably where the > bootloader would put other auxilliary chunks.) > > I'll try to do a full review of this later today. Haven't had time yet > to look at this anything than but piecemeal. Do you think this patch and the 32-bit boot protocol patch are ready to merge for -mm? If not, I can revise them. Best Regards, Huang Ying - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm -v3 1/2] i386/x86_64 boot: setup data
Jeremy Fitzhardinge wrote: > > Do you actually need a linked list of data? This is similar to the > changes to bzImage to support booting bzImage a paravirt environment, > but I just proposed a pointer to a single info structure, along with a > field to identify the boot environment (ie, native/lguest/xen etc). It > would be easy to extend this to handle EFI as just another boot > environment, and you could hang a list of structures off the pointer. > *He* doesn't, but *we* do. We have already run into at least one case where the existing structure is insufficient (EDD overhaul), and so we need to do something extensible. -hpa - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm -v3 1/2] i386/x86_64 boot: setup data
Huang, Ying wrote: > This patch add a field of 64-bit physical pointer to NULL terminated > single linked list of struct setup_data to real-mode kernel > header. This is used as a more extensible boot parameters passing > mechanism. > > This patch has been tested against 2.6.23-rc6-mm1 kernel on x86_64. It > is based on the proposal of Peter Anvin. > > > Known Issues: > > 1. Where is safe to place the linked list of setup_data? > Because the length of the linked list of setup_data is variable, it > can not be copied into BSS segment of kernel as that of "zero > page". We must find a safe place for it, where it will not be > overwritten by kernel during booting up. The i386 kernel will > overwrite some pages after _end. The x86_64 kernel will overwrite some > pages from 0x1000 on. > Do you actually need a linked list of data? This is similar to the changes to bzImage to support booting bzImage a paravirt environment, but I just proposed a pointer to a single info structure, along with a field to identify the boot environment (ie, native/lguest/xen etc). It would be easy to extend this to handle EFI as just another boot environment, and you could hang a list of structures off the pointer. J - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm -v3 1/2] i386/x86_64 boot: setup data
Huang, Ying wrote: > > Known Issues: > > 1. Where is safe to place the linked list of setup_data? > Because the length of the linked list of setup_data is variable, it > can not be copied into BSS segment of kernel as that of "zero > page". We must find a safe place for it, where it will not be > overwritten by kernel during booting up. The i386 kernel will > overwrite some pages after _end. The x86_64 kernel will overwrite some > pages from 0x1000 on. > The latter is definitely not safe, since the space below 640K is the documented place to put the command line (and presumably where the bootloader would put other auxilliary chunks.) I'll try to do a full review of this later today. Haven't had time yet to look at this anything than but piecemeal. -hpa - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH -mm -v3 1/2] i386/x86_64 boot: setup data
This patch add a field of 64-bit physical pointer to NULL terminated
single linked list of struct setup_data to real-mode kernel
header. This is used as a more extensible boot parameters passing
mechanism.
This patch has been tested against 2.6.23-rc6-mm1 kernel on x86_64. It
is based on the proposal of Peter Anvin.
Known Issues:
1. Where is safe to place the linked list of setup_data?
Because the length of the linked list of setup_data is variable, it
can not be copied into BSS segment of kernel as that of "zero
page". We must find a safe place for it, where it will not be
overwritten by kernel during booting up. The i386 kernel will
overwrite some pages after _end. The x86_64 kernel will overwrite some
pages from 0x1000 on.
ChangeLog:
-- v2 --
- Increase the boot protocol version number.
- Check version number before parsing setup_data.
Signed-off-by: Huang Ying <[EMAIL PROTECTED]>
---
arch/i386/Kconfig|3 ---
arch/i386/boot/header.S |8 +++-
arch/i386/kernel/setup.c | 22 ++
arch/x86_64/kernel/setup.c | 21 +
include/asm-i386/bootparam.h | 15 +++
include/asm-i386/io.h|7 +++
6 files changed, 72 insertions(+), 4 deletions(-)
Index: linux-2.6.23-rc6/include/asm-i386/bootparam.h
===
--- linux-2.6.23-rc6.orig/include/asm-i386/bootparam.h 2007-09-19
10:22:02.0 +0800
+++ linux-2.6.23-rc6/include/asm-i386/bootparam.h 2007-09-19
16:41:57.0 +0800
@@ -9,6 +9,17 @@
#include
#include
+/* setup data types */
+#define SETUP_NONE 0
+
+/* extensible setup data list node */
+struct setup_data {
+ u64 next;
+ u32 type;
+ u32 len;
+ u8 data[0];
+} __attribute__((packed));
+
struct setup_header {
u8 setup_sects;
u16 root_flags;
@@ -41,6 +52,10 @@
u32 initrd_addr_max;
u32 kernel_alignment;
u8 relocatable_kernel;
+ u8 _pad2[3];
+ u32 cmdline_size;
+ u32 _pad3;
+ u64 setup_data;
} __attribute__((packed));
struct sys_desc_table {
Index: linux-2.6.23-rc6/arch/i386/boot/header.S
===
--- linux-2.6.23-rc6.orig/arch/i386/boot/header.S 2007-09-19
10:22:02.0 +0800
+++ linux-2.6.23-rc6/arch/i386/boot/header.S2007-09-19 10:47:34.0
+0800
@@ -119,7 +119,7 @@
# Part 2 of the header, from the old setup.S
.ascii "HdrS" # header signature
- .word 0x0206 # header version number (>= 0x0105)
+ .word 0x0207 # header version number (>= 0x0105)
# or else old loadlin-1.5 will fail)
.globl realmode_swtch
realmode_swtch:.word 0, 0# default_switch, SETUPSEG
@@ -214,6 +214,12 @@
#added with boot protocol
#version 2.06
+pad4: .long 0
+
+setup_data:.quad 0 # 64-bit physical pointer to
+ # single linked list of
+ # struct setup_data
+
# End of setup header #
.section ".inittext", "ax"
Index: linux-2.6.23-rc6/arch/x86_64/kernel/setup.c
===
--- linux-2.6.23-rc6.orig/arch/x86_64/kernel/setup.c2007-09-19
10:22:02.0 +0800
+++ linux-2.6.23-rc6/arch/x86_64/kernel/setup.c 2007-09-19 16:41:57.0
+0800
@@ -221,6 +221,25 @@
ebda_size = 64*1024;
}
+void __init parse_setup_data(void)
+{
+ struct setup_data *setup_data;
+ unsigned long pa_setup_data;
+
+ if (boot_params.hdr.version < 0x0207)
+ return;
+ pa_setup_data = boot_params.hdr.setup_data;
+ while (pa_setup_data) {
+ setup_data = early_ioremap(pa_setup_data, PAGE_SIZE);
+ switch (setup_data->type) {
+ default:
+ break;
+ }
+ pa_setup_data = setup_data->next;
+ early_iounmap(setup_data, PAGE_SIZE);
+ }
+}
+
void __init setup_arch(char **cmdline_p)
{
printk(KERN_INFO "Command line: %s\n", boot_command_line);
@@ -256,6 +275,8 @@
strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;
+ parse_setup_data();
+
parse_early_param();
finish_e820_parsing();
Index: linux-2.6.23-rc6/arch/i386/kernel/setup.c
===
--- linux-2.6.23-rc6.orig/arch/i386/kernel/setup.c 2007-09-19
10:22:02.0 +0800
+++ linux-2
