linux-kernel - Re: [PATCH] x86: Setup early console as early as possible

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4C3B38F7.1050400@zytor.com>
Date:	Mon, 12 Jul 2010 08:47:03 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Pekka Enberg <penberg@...helsinki.fi>
CC:	Yinghai Lu <yinghai.lu@...cle.com>, Ingo Molnar <mingo@...e.hu>,
	Thomas Gleixner <tglx@...utronix.de>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] x86: Setup early console as early as possible

On 07/12/2010 01:58 AM, Pekka Enberg wrote:
> Hi Yinghai,
> 
> Yinghai Lu wrote:
>> Analyze "console=uart8250,io,0x3f8,115200n8" in
>> i386_start_kernel/x86_64_start_kernel,
>> and call setup_early_serial8250_console() to init early serial console.
>>
>> only can handle io port kind of 8250. because mmio need ioremap.
>>
>> Signed-off-by: Yinghai Lu <yinghai@...nel.org>
> 
> What's the purpose of this patch? Does it make my early boot I/O patch
> obsolete?
> 
>             Pekka

No, they're complementary.  Your patch serial-port enables the RM
kernel, whereas Yinghai pushes the initialization earlier in the PM kernel.

Incidentally, Yinghai: it would be possible to push even an MMIO
reference earlier by reserving a fixmap slot for the early console.  I'm
not sure if it's worth it, though.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/