# fail to recompile kernel with costum ACPI DSDT patch

## pd1986

I have a DSDT patch in .hex, But I can't where I can set the path in the kernel configuration. I find that in .config but it doesn't work. it ignores what I set. 

CONFIG_ACPI_CUSTOM_DSDT_FILE="DSDT_patch.hex"

and it recovers .config to default. 

I am using gentoo-sources-3.8.6

So what should I do? Thanks.

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## TomWij

Provide more information about how you compile your kernel, in which place you place the DSDT, etc...

Also, why change the DSDT instead of the kernel? What are you trying to patch here? Where did you get the DSDT from? What are you changing?

Note that this taints your kernel, so you may not see any support for any future problems continuing with this approach.

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## Yamakuzure

You do *not* add a hex code, but a header file, or a compiled .aml file. (But you can de-compile and re-compile the hex file. See https://wiki.archlinux.org/index.php/DSDT)

The header goes here:

CONFIG_ACPI_CUSTOM_DSDT_FILE="/path/to/your/dsdt_table.h"

CONFIG_ACPI_CUSTOM_DSDT=y

The .aml file can be loaded via a boot manager. In grub2 it is here:

```
 ~ $ grep DSDT -A 1 -B 1 /etc/grub.d/30_os-prober 

           xnu_uuid ${OSXUUID} uuid

           if [ -f /Extra/DSDT.aml ]; then

              acpi -e /Extra/DSDT.aml

           fi
```

(I do not know about grub1, lilo, syslinux etc...)

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## pd1986

 *TomWij wrote:*   

> Provide more information about how you compile your kernel, in which place you place the DSDT, etc...
> 
> Also, why change the DSDT instead of the kernel? What are you trying to patch here? Where did you get the DSDT from? What are you changing?
> 
> Note that this taints your kernel, so you may not see any support for any future problems continuing with this approach.

 

I compile the kernel manually, "make menuconfig" then "make && make modules_install"

I put the DSDT patch in one user's directory.

The cpu fan never starts automatically, I always need to start manually. but sometimes it doesn't modulate properly. I got the patch file from bugzilla, someone provided. He made some changes in the fan control part.

I understand the risk that I will take.Last edited by pd1986 on Wed May 15, 2013 3:39 pm; edited 1 time in total

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## pd1986

 *Yamakuzure wrote:*   

> You do *not* add a hex code, but a header file, or a compiled .aml file. (But you can de-compile and re-compile the hex file. See https://wiki.archlinux.org/index.php/DSDT)
> 
> The header goes here:
> 
> CONFIG_ACPI_CUSTOM_DSDT_FILE="/path/to/your/dsdt_table.h"
> ...

 

I found that guide too. 

But I tried modifying the .config file like what you cited here. but it doesn't work, when I run "make" the .config file will be rewritten and set to default which is "CONFIG_ACPI_CUSTOM_DSDT is not set"

I only have patch file DSDT_patch.hex but not .aml file. What's more, I am still using grub1. it works fine so I don't have a plan to move to grub2

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## TomWij

 *pd1986 wrote:*   

> The cpu fan never starts automatically, I always need to start manually.

 

You could see whether a BIOS update is available if you're looking for support in the future.

Good luck with the patch, doing it in the boot loader instead of the kernel sounds like a good idea.

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## pd1986

 *TomWij wrote:*   

>  *pd1986 wrote:*   The cpu fan never starts automatically, I always need to start manually. 
> 
> You could see whether a BIOS update is available if you're looking for support in the future.
> 
> Good luck with the patch, doing it in the boot loader instead of the kernel sounds like a good idea.

 

Thanks

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