[debian-yeeloong-project] d-i Yeeloong port in progress

[Colin Watson]

On Fri, Jun 03, 2011 at 05:56:40PM +0200, Robert Millan wrote:
> 2011/6/3 Colin Watson <cjwatson at debian.org>:
> > Perhaps no_auto_cmd is also a historical artifact.  Robert, do you
> > happen to know?
> 
> I think it's a PMON argument. ISTR it prevents PMON from passing its own
> hardcoded cmdline to Linux.

Thanks for your reply.

That would make sense, and
http://zhangle.co/2009/07/%E9%BE%99%E6%A2%A6%E7%AC%94%E8%AE%B0%E6%9C%AC%E5%86%85%E6%A0%B8%E6%9C%89%E4%B8%AAno_auto_cmd%E5%8F%82%E6%95%B0/
(after translation) seems to indicate something similar.  However, I
grepped through the entire history of git://dev.lemote.com/pmon.git and
couldn't find anything that ever interpreted that argument.

I experimented with booting d-i on my borrowed Yeeloong system with and
without no_auto_cmd:

  PMON> vers
  PMON: PMON2000 2.1 (Bonito) #292: Fri Aug 14 09:07:52 CST 2009

  PMON> load (usb0,0)/vmlinux
  PMON> initrd (usb0,0)/initrd.gz
  PMON> g
  # cat /proc/cmdline
  PMON_VER=LM8089-1.4.5 EC_VER=PQ1D20 rd_start=0x84000000 rd_size=0x9c9505  machtype=lemote-yeeloong-2f-8.9inches

  PMON> load (usb0,0)/vmlinux
  PMON> initrd (usb0,0)/initrd.gz
  PMON> g foobar
  # cat /proc/cmdline
  foobar PMON_VER=LM8089-1.4.5 EC_VER=PQ1D20 rd_start=0x84000000 rd_size=0x9c9505  machtype=lemote-yeeloong-2f-8.9inches

  PMON> load (usb0,0)/vmlinux
  PMON> initrd (usb0,0)/initrd.gz
  PMON> g no_auto_cmd
  # cat /proc/cmdline
  no_auto_cmd PMON_VER=LM8089-1.4.5 EC_VER=PQ1D20 rd_start=0x84000000 rd_siz=0x9c9505  machtype=lemote-yeeloong-2f-8.9inches

  PMON> load (usb0,0)/vmlinux
  PMON> initrd (usb0,0)/initrd.gz
  PMON> g no_auto_cmd foobar
  # cat /proc/cmdline
  no_auto_cmd foobar PMON_VER=LM8089-1.4.5 EC_VER=PQ1D20 rd_start=0x84000000 rd_siz=0x9c9505  machtype=lemote-yeeloong-2f-8.9inches

There's no sign here of no_auto_cmd having any effect whatsoever.

I happened to find a reference that led me to do some archaeology on the
linux-mips tree and mailing list.  I found this:

  http://www.linux-mips.org/archives/linux-mips/2009-06/msg00157.html

That shows no_auto_cmd being handled by kernel setup code.  But, by the
time that patch set reached v4
(http://www.linux-mips.org/archives/linux-mips/2009-07/msg00061.html),
there was no trace of that code any more, and the versions that actually
made it into mainline Linux looked a lot more like current
arch/mips/loongson/common/cmdline.c.

Thus, I think that no_auto_cmd dates from a certain vintage of the
Lemote vendor branch, but is no longer applicable to modern mainline
kernels such as that in Debian unstable, and we can forget about both
console=tty and no_auto_cmd in instructions for installing Wheezy.  Do
you agree?

Thanks,

-- 
Colin Watson                                       [cjwatson at debian.org]