OK thanks for info

Petr

Dne 25. 04. 22 v 8:30 Arthur Heymans napsal(a):
> Hi
> 
> 2M TSEG is hardcoded in nb/intel/i945/early_init.c so it should never have an 
> 8M value.
> 
> --
> Arthur
> 
> On Mon, Apr 25, 2022 at 8:22 AM Petr Cvek <[email protected] 
> <mailto:[email protected]>> wrote:
> 
>     Dne 25. 04. 22 v 7:51 Arthur Heymans napsal(a):
>     > 4MB IGD stolen memory is fine for 2M alignment on TSEG, so only 
> dropping 1M would be needed.
> 
>     Yeah but TSEG can have 8MB and will require 8MB alignment (however I 
> don't know if this setting is used in coreboot).
> 
>     Petr
> 
>     > Also that value goes up to 64MB, not 8M, but it's not documented in the 
> official documentation.
>     >
>     > Kind regards,
>     > Arthur
>     >
>     > On Sun, Apr 24, 2022 at 11:54 PM Petr Cvek <[email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>>> wrote:
>     >
>     >     Thanks! I would never find the SMRR feature.
>     >
>     >     Hmm that means 4MB stolen memory should be dropped along 1MB (TSEG 
> can up to 8MB on i945). Or alternatively to check if TSEG >= UMA in cmos 
> configuration. I suppose cmos.layout would need to support some kind of 
> scripting though.
>     >
>     >     Petr
>     >
>     >     Dne 24. 04. 22 v 18:56 Arthur Heymans napsal(a):
>     >     > Hi
>     >     >
>     >     > You want to align tseg for when smrr is supported by the CPU. I 
> would just drop support for 1MB stolen memory.
>     >     >
>     >     > Arthur
>     >     >
>     >     > On Sun, 24 Apr 2022, 05:40 Petr Cvek, <[email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>> <mailto:[email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>>>> wrote:
>     >     >
>     >     >     Hello,
>     >     >
>     >     >     On i945 northbridge:
>     >     >
>     >     >             ASSERTION ERROR: file 
> 'src/cpu/x86/smm/tseg_region.c', line 31
>     >     >
>     >     >     can be triggered by some configurations. The assert
>     >     >
>     >     >             ASSERT(IS_ALIGNED(sub_base, sub_size));
>     >     >
>     >     >     tests alignment of SMM base with SMM size. The problem is 
> that IGD stolen memory can offset the SMM base by a smaller size than the SMM 
> size. This causes SMM base to be unaligned. For example:
>     >     >
>     >     >     80000000: 2 GiB Top of RAM, stored in TOLUD
>     >     >     7ff00000: 1 MiB Stolen IGD RAM base, address in BSM
>     >     >     7fd00000: 2 MiB SMM base, defined as SMM size in ESMRAMC
>     >     >
>     >     >     -> 0x7fd00000 is not aligned to SMM size. Probably works for 
> different settings too.
>     >     >
>     >     >     RFC: should the assert from
>     >     >
>     >     >             
> https://elixir.bootlin.com/coreboot/4.16/source/src/cpu/x86/smm/tseg_region.c#L31
>  
> <https://elixir.bootlin.com/coreboot/4.16/source/src/cpu/x86/smm/tseg_region.c#L31>
>  
> <https://elixir.bootlin.com/coreboot/4.16/source/src/cpu/x86/smm/tseg_region.c#L31
>  
> <https://elixir.bootlin.com/coreboot/4.16/source/src/cpu/x86/smm/tseg_region.c#L31>>
>  
> <https://elixir.bootlin.com/coreboot/4.16/source/src/cpu/x86/smm/tseg_region.c#L31
>  
> <https://elixir.bootlin.com/coreboot/4.16/source/src/cpu/x86/smm/tseg_region.c#L31>
>  
> <https://elixir.bootlin.com/coreboot/4.16/source/src/cpu/x86/smm/tseg_region.c#L31
>  
> <https://elixir.bootlin.com/coreboot/4.16/source/src/cpu/x86/smm/tseg_region.c#L31>>>
>     >     >
>     >     >     be removed, changed or ignored on i945? The correct test 
> should be probably for 1 MiB alignement as the base of stolen IGD memory have 
> [31:20] bits. But I understand the smm_subregion() test is a generic one.
>     >     >
>     >     >     regards,
>     >     >     Petr
>     >     >     _______________________________________________
>     >     >     coreboot mailing list -- [email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>> <mailto:[email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>>>
>     >     >     To unsubscribe send an email to [email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>> <mailto:[email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>>>
>     >     >
>     >
> 
_______________________________________________
coreboot mailing list -- [email protected]
To unsubscribe send an email to [email protected]

Reply via email to