[PATCH] Add 2 more E820 to ACPI specification

[PATCH] Add 2 more E820 to ACPI specification

[Vladimir 'φ-coder/phcoder' Serbinenko]

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Hello. This defines 2 more types for mmap_type in a way to match E820
values. As grub legacy and grub2 both just pass E820 values through it
shouldn't be any problem.

-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko


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=== modified file 'doc/multiboot.texi'
--- doc/multiboot.texi	2010-01-12 16:49:46 +0000
+++ doc/multiboot.texi	2010-01-15 16:52:03 +0000
@@ -817,7 +817,9 @@
 can be greater than the minimum of 20 bytes. @samp{base_addr} is the
 starting address. @samp{length} is the size of the memory region in bytes.
 @samp{type} is the variety of address range represented, where a
-value of 1 indicates available @sc{ram}, and all other values currently
+value of 1 indicates available @sc{ram}, value of 3 indicates usable memory
+holding ACPI information, value of 4 indicates reserved memory which needs to
+be preserved on hibernation and all other values currently
 indicated a reserved area.
 
 The map provided is guaranteed to list all standard @sc{ram} that should


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Re: [PATCH] Add 2 more E820 to ACPI specification

[Robert Millan]

On Fri, Jan 15, 2010 at 06:18:43PM +0100, Vladimir 'φ-coder/phcoder' Serbinenko wrote:
> Hello. This defines 2 more types for mmap_type in a way to match E820
> values. As grub legacy and grub2 both just pass E820 values through it
> shouldn't be any problem.

Note that although Multiboot's memory map format is modelled after e820,
it is defined by us, not by BIOS vendors.

> -value of 1 indicates available @sc{ram}, and all other values currently
> +value of 1 indicates available @sc{ram}, value of 3 indicates usable memory
> +holding ACPI information,

I'm concerned about increasing the amount of arch-specific references; what do
Multiboot kernels that use ACPI currently do?

> value of 4 indicates reserved memory which needs to
> +be preserved on hibernation and all other values currently
>  indicated a reserved area.

What's the difference between this reserved memory and a reserved area?

-- 
Robert Millan

  "Be the change you want to see in the world" -- Gandhi

Re: [PATCH] Add 2 more E820 to ACPI specification

[Vladimir 'φ-coder/phcoder' Serbinenko]

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Robert Millan wrote:
> On Fri, Jan 15, 2010 at 06:18:43PM +0100, Vladimir 'φ-coder/phcoder' Serbinenko wrote:
>   
>> Hello. This defines 2 more types for mmap_type in a way to match E820
>> values. As grub legacy and grub2 both just pass E820 values through it
>> shouldn't be any problem.
>>     
>
> Note that although Multiboot's memory map format is modelled after e820,
> it is defined by us, not by BIOS vendors.
>
>   
Yes, but this information is needed and I prefer to provide it in
grub-legacy-compatible way.
>> -value of 1 indicates available @sc{ram}, and all other values currently
>> +value of 1 indicates available @sc{ram}, value of 3 indicates usable memory
>> +holding ACPI information,
>>     
>
> I'm concerned about increasing the amount of arch-specific references; what do
> Multiboot kernels that use ACPI currently do?
>
>   
According to a post by Bernard Trotter many of them rely on multiboot
loader passing e820 through
>> value of 4 indicates reserved memory which needs to
>> +be preserved on hibernation and all other values currently
>>  indicated a reserved area.
>>     
>
> What's the difference between this reserved memory and a reserved area?
>
>   
"which needs to be preserved on hibernation and all other values currently"
Payload should never write to or read from type 2 memory. But it needs
to save type 4 memory into its hibernation file when it hibernates and
restore on resume.


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



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Re: [PATCH] Add 2 more E820 to ACPI specification

[Robert Millan]

On Wed, Jan 20, 2010 at 12:17:26AM +0100, Vladimir 'φ-coder/phcoder' Serbinenko wrote:
> Robert Millan wrote:
> > On Fri, Jan 15, 2010 at 06:18:43PM +0100, Vladimir 'φ-coder/phcoder' Serbinenko wrote:
> >   
> >> Hello. This defines 2 more types for mmap_type in a way to match E820
> >> values. As grub legacy and grub2 both just pass E820 values through it
> >> shouldn't be any problem.
> >>     
> >
> > Note that although Multiboot's memory map format is modelled after e820,
> > it is defined by us, not by BIOS vendors.
> >
> >   
> Yes, but this information is needed and I prefer to provide it in
> grub-legacy-compatible way.
> >> -value of 1 indicates available @sc{ram}, and all other values currently
> >> +value of 1 indicates available @sc{ram}, value of 3 indicates usable memory
> >> +holding ACPI information,
> >>     
> >
> > I'm concerned about increasing the amount of arch-specific references; what do
> > Multiboot kernels that use ACPI currently do?
> >
> >   
> According to a post by Bernard Trotter many of them rely on multiboot
> loader passing e820 through

I just checked GRUB Legacy;  it seems that it is passing through the whole
thing.  I think this was a mistake, but it's too late to fix it now.

Feel free to commit this.

-- 
Robert Millan

  "Be the change you want to see in the world" -- Gandhi