From: "H. Peter Anvin" <hpa@zytor.com>
To: Yinghai Lu <yinghai@kernel.org>
Cc: Haren Myneni <hbabu@us.ibm.com>,
Simon Horman <horms@verge.net.au>,
kexec@lists.infradead.org,
"Eric W. Biederman" <ebiederm@xmission.com>,
Vivek Goyal <vgoyal@redhat.com>
Subject: Re: [PATCH v6 3/6] kexec, x86: Fix bzImage real-mode booting
Date: Thu, 13 Dec 2012 15:42:55 -0800 [thread overview]
Message-ID: <50CA67FF.90009@zytor.com> (raw)
In-Reply-To: <1355437112-9250-4-git-send-email-yinghai@kernel.org>
On 12/13/2012 02:18 PM, Yinghai Lu wrote:
> + if (real_mode_entry) {
> + /* restore can use heap and load high */
> + real_mode->loader_flags = 0x81;
> + if (real_mode->protocol_version >= 0x0201)
> + real_mode->heap_end_ptr += heap_size - 0x200; /*stack*/
> + }
> +
This code is wrong: the bits at the bottom of this field (LOADED_HIGH)
are kernel->bootloader flags.
The right behavior is:
if (real_mode->protocol_version >= 0x0201) {
real_mode->loader_flag |= CAN_USE_HEAP;
real_mode->heap_end_ptr += heap_size - 0x200; /*stack*/
}
> + regs16.ds = regs16.es = regs16.fs = regs16.gs = setup_base >> 4;
> + regs16.cs = regs16.ds + 0x20;
> + regs16.ip = 0;
> + /* XXX: Documentation/i386/boot.txt says 'ss' must equal 'ds' */
> + regs16.ss = (elf_rel_get_addr(&info->rhdr, "stack_end") - 64*1024) >> 4;
> + /* XXX: Documentation/i386/boot.txt says 'sp' must equal heap_end */
> + regs16.esp = 0xFFFC;
> +
And, pray tell, why aren't they?
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2012-12-13 23:43 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-13 22:18 [PATCH v6 0/6] kexec: put bzImage and ramdisk above 4G for x86 64bit Yinghai Lu
2012-12-13 22:18 ` [PATCH v6 1/6] kexec, x86: add boot header member for version 2.12 Yinghai Lu
2012-12-13 22:18 ` [PATCH v6 2/6] kexec, x86: clean boot_params area for entry-32bit path Yinghai Lu
2012-12-13 22:18 ` [PATCH v6 3/6] kexec, x86: Fix bzImage real-mode booting Yinghai Lu
2012-12-13 23:42 ` H. Peter Anvin [this message]
2012-12-14 0:06 ` Yinghai Lu
2012-12-13 22:18 ` [PATCH v6 4/6] kexec, x86: put ramdisk/cmd_line above 4G for 64bit bzImage Yinghai Lu
2012-12-13 22:18 ` [PATCH v6 5/6] kexec, x86_64: Load bzImage64 above 4G Yinghai Lu
2012-12-13 22:18 ` [PATCH v6 6/6] kexec, x86: handle Crash low kernel range Yinghai Lu
2012-12-14 0:41 ` [PATCH v6 0/6] kexec: put bzImage and ramdisk above 4G for x86 64bit H. Peter Anvin
2012-12-14 0:47 ` Yinghai Lu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=50CA67FF.90009@zytor.com \
--to=hpa@zytor.com \
--cc=ebiederm@xmission.com \
--cc=hbabu@us.ibm.com \
--cc=horms@verge.net.au \
--cc=kexec@lists.infradead.org \
--cc=vgoyal@redhat.com \
--cc=yinghai@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.