From: pebolle@tiscali.nl (Paul Bolle)
To: kernelnewbies@lists.kernelnewbies.org
Subject: realmode _WAKEUP
Date: Wed, 07 Jan 2015 19:57:26 +0100 [thread overview]
Message-ID: <1420657046.24143.18.camel@x220> (raw)
In-Reply-To: <CANCZXo5v-H1_q_qzk=SOoPqnY-hZ+LxNzaapx8OPv4U5Mq5Zcw@mail.gmail.com>
On Wed, 2015-01-07 at 23:59 +0600, Alexander Kuleshov wrote:
> Yes i saw video-*.c files, but i can't understand how compilation of
> these video-*.c files depends on _WAKEUP macro...
>
> For example if'd remove -D_WAKEUP, i get errors during realmode.elf linking:
>
> arch/x86/realmode/rm/video-vga.o: In function `vga_probe':
> /home/alex/dev/linux/arch/x86/realmode/rm/../../boot/video-vga.c:259:
> undefined reference to `boot_params'
>
> As you wrote there are many #ifndef/#endif directives, but why there
> _WAKEUP is undefined everytime, but we pass it from command line with
> -D_WAKEUP?
Because these file also get compiled via arch/x86/boot/Makefile? Ie, I
_guess_ _WAKEUP is needed to ensure the compile started from
arch/x86/realmode/rm/Makefile differs from the compile started from
arch/x86/boot/Makefile. But [...]/boot/Makefile is sufficiently
complicated for me to stop me from looking at it too long!
You do realize that the Linux kernel is a treasure trove for people
wanting to know just how far make, gcc, etc can be pushed, don't you?
Paul Bolle
next prev parent reply other threads:[~2015-01-07 18:57 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-07 14:12 realmode _WAKEUP Alexander Kuleshov
2015-01-07 16:54 ` Paul Bolle
2015-01-07 17:13 ` Paul Bolle
2015-01-07 17:59 ` Alexander Kuleshov
2015-01-07 18:02 ` Alexander Kuleshov
2015-01-07 19:02 ` Paul Bolle
2015-01-07 18:57 ` Paul Bolle [this message]
2015-01-07 19:11 ` Alexander Kuleshov
-- strict thread matches above, loose matches on Subject: below --
2015-01-07 19:11 Alexander Kuleshov
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=1420657046.24143.18.camel@x220 \
--to=pebolle@tiscali.nl \
--cc=kernelnewbies@lists.kernelnewbies.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).