From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Mosberger Date: Tue, 13 May 2003 07:25:59 +0000 Subject: Re: [Linux-ia64] Dump driver module Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org >>>>> On Tue, 13 May 2003 09:02:48 +0200, Bruno Vidal said: Bruno> I've already wrote a dump modules driver for linux-parisc. Bruno> This module goal is to create a memory image on a swap area, and Bruno> at reboot time to save it to disk with all kernel modules, in Bruno> order to analyze it after by "support" people with tools like Bruno> gdb/p4. The problem while dumping is that the dump modules Bruno> cannot trust anymore the system, so dumping means: no interruption, Bruno> no disk driver, no buffer, nothing. The solution is to use low level Bruno> call. For parisc I use the IODC calls, for ia64 I think I'll Bruno> use the EFI calls. My questions: Bruno> -do you think it is a "good" and realistic solution. Bruno> -because I think "yes", does exist somewhere an example of Bruno> reading/writing with EFI call on disk using BLOCK IO. I've already Bruno> looked in elilo, but it seems that it use FS access. Once the kernel is booted, you can access only the EFI runtime services (see struct efi in include/linux/efi.h). I'm afraid there is no support for writing disk blocks. Given this limitation, I suspect you'd have to include your own (simple) disk driver(s). --david