conf/144548: Automatic dual kernel cd boot amd64/i386

Alexei Volkov Alexei.Volkov at
Mon Mar 8 11:00:19 UTC 2010

>Number:         144548
>Category:       conf
>Synopsis:       Automatic dual kernel cd boot amd64/i386
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Mon Mar 08 11:00:11 UTC 2010
>Originator:     Alexei Volkov
>Release:        8.0-RELEASE-p28.0-RELEASE-p2
FreeBSD 8.0-RELEASE-p2 FreeBSD 8.0-RELEASE-p2 #1: Tue Jan 26 06:30:15 UTC 2010     root at  amd64

I wood like to to get bootable cd with auto selectable amd64/i386 boot kernel, but did not find any solution in current boot facilities.

For instance, if i have a bootable cd with two kernels located /boot/kernel.amd64
and /boot/kernel.i386 accordingly it looks pretty logical to have loader.conf  line like /kernel=kernel.${hw.machine} and it let boots up amd64 kernel if long mode supported.

append loader.conf with line 


andd see nothing will happend event you have kernels in a assumed path.
I found that the boot facilities has everything to setup the hw.machine kernel environment variable, but does't do that.

Is it right to setup hw.machine kernel variable with a patch attached?

Patch attached with submission follows:

--- /usr/src/sys/boot/i386/loader/main.c        2010-02-10 12:36:20.468937250 +0300
+++ /usr/src/sys/boot/i386/loader/main.c        2010-02-10 12:36:49.796728917 +0300
@@ -185,6 +185,11 @@
     setenv("LINES", "24", 1);                  /* optional */

+    if (bi_checkcpu())
+       setenv("hw.machine","amd64",1);
+    else
+       setenv("hw.machine","i386",1);

     interact();                        /* doesn't return */

--- /usr/src/sys/boot/i386/libi386/bootinfo64.c    2010-02-10 12:36:32.213285664 +0300
+++ /usr/src/sys/boot/i386/libi386/bootinfo64.c    2010-02-10 12:19:17.000000000 +0300
@@ -129,7 +129,7 @@
  * Check to see if this CPU supports long mode.
-static int
     char *cpu_vendor;


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