linux-mips
[Top] [All Lists]

Re: How does boot loader tell the kernel, the location of initrd?

To: "Thierry Reding" <thierry@gilfi.de>, "Thiemo Seufer" <ths@networkno.de>
Subject: Re: How does boot loader tell the kernel, the location of initrd?
From: "Rajat Jain" <rajat.noida.india@gmail.com>
Date: Fri, 16 Mar 2007 10:42:30 +0530
Cc: kernelnewbies@nl.linux.org, newbie <linux-newbie@vger.kernel.org>, linux-mips@linux-mips.org
Dkim-signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=kfnUQk9BzgxG2cu/VVcdMYuZYY4i3Wp0QpRthfQ4Tb1a6tmp4rkfm926JWn2otPJi4Z1DvTmwoLgl2CyadU0TLb1oi9ORsBcuGml5nOtOgSktW/0DXAW/Ze68ml3rXQ16oNn2xOV75LeCeCvsfuGWmaoJqMGg5TJkhiQCRSjDug=
Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=VW9J4LY8ephpZYg1DHaqJfpynmd7rIKNZg2b6xd+6XR1W5guxU4c5k9Lrgxg/SKmkQpvbJnyA2KVwLUupD7+ROYQghqgYyYLi30AixXwaq7DvWiNnTYfg2jw9xSmDgdEj7payAuMFX7H+J2rKrc54iZRbA6//cfgHckXwZ6nPUI=
In-reply-to: <20070315161718.GB16545@ba.sec>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <b115cb5f0703142358j6a422262qe1ad1c6cfcfcdd22@mail.gmail.com> <20070315161718.GB16545@ba.sec>
Sender: linux-mips-bounce@linux-mips.org
> I am experimenting with initrd and my initrd fails to mount. My
> bootloader (U-BOOT) coorectly loads the initrd into RAM as I can see.
>
> I am wondering how does the kernel get to know the address at which
> the initrd is loaded by boot loader? How does the boot loader
> communicate this to the kernel?
>
> Any code references will be appreciated.

Perhaps lib_mips/mips_linux.c in the U-Boot tree is what you are looking for.
That code sets up environment parameters that are parsed by the Linux kernel
later on (see rd_start_early() and friends in arch/mips/kernel/setup.c in the
Linux tree).

Thanks! That is exactly what I was looking for. However, I noticed
that U-BOOT passes these parameters in environment variables, where as
Linux kernel expects them as command l ine arguments. It wasn't
working for me untill I made changes in U-BOOT to pass them in command
line arguments.

Why is this discrepancy in U-BOOT and the kernel? Are other people
working on the (linux+U-BOOT) combo making the changes that I did?

Thanks,,

Rajat

<Prev in Thread] Current Thread [Next in Thread>
  • Re: How does boot loader tell the kernel, the location of initrd?, Rajat Jain <=