Re: [PATCH -mm -v2] x86 boot : export boot_params via sysfs

From: H. Peter Anvin
Date: Wed Dec 12 2007 - 13:09:53 EST


Greg KH wrote:
On Wed, Dec 12, 2007 at 04:59:51PM +0800, Huang, Ying wrote:
This patch export the boot parameters via sysfs. This can be used for
debugging and kexec.

The files added are as follow:

/sys/kernel/boot_params/data : binary file for struct boot_params
/sys/kernel/boot_params/version : boot protocol version

This patch is based on 2.6.24-rc4-mm1 and has been tested on i386 and
x86_64 platoform.

This patch is based on the Peter Anvin's proposal.

As outlined in a previous email, I object to the whole structure being
exported to userspace as a binary blob. Please change that.


I would prefer to have the binary blob available; exported fields is possible too, of course.

This is a binary structure defined by protocol; in that way it's not significantly different from something passed from the firmware (in fact, it might very well *be* passed from the firmware.) We have in the past found platform bugs by looking at the contents of the whole structure, e.g. to find that part of it has been inappropriately clobbered.

It is also in the form needed by e.g. kexec to operate.

-hpa
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