Re: [PATCH] x86,setup: add serial_console_port_base in boot_params

[Yinghai Lu <yinghai@kernel.org>]

On 07/31/2010 07:42 PM, Eric W. Biederman wrote:
> Yinghai Lu <yinghai@kernel.org> writes:
> 
>> On 07/31/2010 02:02 PM, H. Peter Anvin wrote:
>>> On 07/31/2010 11:32 AM, Cyrill Gorcunov wrote:
>>>>>
>>>>> No, this is the internal part of the boot protocol, so it's not an issue.
>>>>>
>>>>
>>>> Peter, I didn't mean any issue here, I meant that bootloaders don't know about
>>>> this field yet and they will have to update own sources to pass port value
>>>> at proper place of boot params. Or I miss something?
>>>>
>>>
>>> Boot loaders that use the 16-bit entry point are unaffected.
>>>
>>> Boot loaders which use the 32-bit entry point but properly clears the
>>> zero page simply will not have the feature.
>>>
>>> Boot loaders which use the 32-bit entry point but doesn't clear the zero
>>> page are broken.
>>>
>> can you if this one is right for kexec path?
> 
> I am walking out the door, but this seems like nonsense to me.
> 
> Further I don't see why we would add something to the zero page
> when we have a perfectly good way to pass this information via
> the kernel command line.  strstr and strtoul are trivial little
> functions so I don't see why anything would need to parse anything
> other than console= or early_printk=.  The difference in code size
> is negligible.
> 
so you prefer to check command line for console info in arch/x86/boot/compressed/misc.c again?

that commandline is analyzed in arch/x86/boot/tty.c already.

Yinghai