Date: Thu, 4 Sep 2014 21:23:19 +0000 From: "Sinha, Prokash" <psinha@panasas.com> To: John Baldwin <jhb@freebsd.org> Cc: "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org> Subject: Re: PXE boot Message-ID: <D02E2653.192A%psinha@panasas.com> In-Reply-To: <D02E2555.1921%psinha@panasas.com> References: <D02C8BE1.179F%psinha@panasas.com> <D02DE132.18A0%psinha@panasas.com> <D02DE270.18AA%psinha@panasas.com> <2303890.kxxKhV23z4@ralph.baldwin.cx> <D02E2555.1921%psinha@panasas.com>
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On 9/4/14 2:22 PM, "Sinha, Prokash" <psinha@panasas.com> wrote:
>Yeah, something going on that I don't understand. I defined that macro,
>and for quick verify -
>make -v=20
>Warning: Object directory not changed from original
>/.automount/nfs.paneast.panasas.com/root/home/psinha/psinha-bug-pa/src/fre
>e
>bsd-c/sys/boot/i386/pxeldr
>cc -O2 -fno-strict-aliasing -pipe -ffreestanding
>-mpreferred-stack-boundary=3D2 -mno-mmx -mno-3dnow -mno-sse -mno-sse2
>-mno-sse3 -m32 -march=3Di386 -DALWAYS_SERIAL -c pxeldr.S
>cc -O2 -fno-strict-aliasing -pipe -ffreestanding
>-mpreferred-stack-boundary=3D2 -mno-mmx -mno-3dnow -mno-sse -mno-sse2
>-mno-sse3 -m32 -march=3Di386 -DALWAYS_SERIAL -nostdlib -m elf_i386_fbsd =
-N
>-e start -Ttext 0x7c00 -Wl,-S,--oformat,binary -o pxeldr pxeldr.o
>make: don't know how to make pxeboot.8. Stop
>
>=3D=3D> The variable is defined and the correct flag is included in the cc=
...
>
>
>But I still don't get the messages from pxe_enable or pxe_init...
>
>Need to sit back and look further...
>
>John, much appreciated for the help...
>
>If anything else you can think of, please drop couple lines for me to
>investigate...
>-prokash
>
>On 9/4/14 10:53 AM, "John Baldwin" <jhb@freebsd.org> wrote:
>
>>On Thursday, September 04, 2014 04:33:46 PM Sinha, Prokash wrote:
>>> On 9/4/14 9:31 AM, "Sinha, Prokash" <psinha@panasas.com> wrote:
>>> >Thanks once again...
>>> >
>>> >This is the part - that you spelled out is why I had a trace in the
>>> >pxe_enable(...) routine. As well as at pxe_init( ...) routine, just to
>>>be
>>> >sure
>>> >the pxe.c routines are working like ( as you said ) devsw invocation.
>>>But
>>> >did not see the trace messages, could be serial console is not acting
>>>(
>>> >though I doubt it).
>>> >
>>> >Now gave me a base, off of what I could debug ...
>>
>>Hmm, the console should be working (cons_probe() is called before
>>pxe_enable()). However, if you are using 'console=3Dcomconsole' in
>>loader.conf=20
>>to set a serial console, you won't see early messages because loader.conf
>>is=20
>>processed after main() calls interact() at the bottom of the function.
>>If you=20
>>want to see early loader messages on serial, you will need to build
>>pxeboot=20
>>with BOOT_PXELDR_ALWAYS_SERIAL defined as a make variable (so on the
>>command=20
>>line, or in /etc/make.conf or /etc/src.conf). That will force a serial
>>console for early loader messages.
>>
>>> >
>>> >-prokash
>>> >
>>> >On 9/4/14 7:57 AM, "John Baldwin" <jhb@freebsd.org> wrote:
>>> >>On Wednesday, September 03, 2014 11:16:05 PM Sinha, Prokash wrote:
>>> >>> Thanks much, John !
>>> >>>=20
>>> >>> When it starts executing ? How ?. Who starts executing these. From
>>>the
>>> >>> Makefile it's org is 0x7c00. So I would assume that it would be
>>>loaded
>>> >>>
>>> >>>at
>>> >>>
>>> >>> that absolute real-mode address !. I don't understand this part.
>>>But,
>>> >>>
>>> >>>if I
>>> >>>
>>> >>> put traces, I see pxe_open, and pxe_close are being called, but
>>>after
>>> >>>
>>> >>>all
>>> >>>
>>> >>> these pxe_calls are done, the loader's main is invoked at Rebooting
>>>=A9
>>> >>>
>>> >>>time.
>>> >>>
>>> >>> We are using a net boot server, and I see mountd- authenticated =A9
>>> >>>
>>> >>>message
>>> >>>
>>> >>> storm on the boot server side.
>>> >>>=20
>>> >>> Wondering what could cause such a message storm, while pxe_open()
>>>->
>>> >>>
>>> >>>net
>>> >>>
>>> >>> if_open( ) executes.
>>> >>
>>> >>The PXE BIOS uses TFTP to fetch the pxeboot binary (and it will do
>>>its
>>> >>own
>>> >>DHCP, etc. as part of doing that). It writes the binary it downloads
>>> >>starting
>>> >>at address 0x7c00. Once the download is complete, it jumps to 0x7c00
>>> >>similar
>>> >>to how booting from a disk loads the first sector at address 0x7c00
>>>and
>>> >>then
>>> >>jumps to it.
>>> >>
>>> >>The PXE calls in libi386 should not be invoked until the loader
>>>main()
>>> >>routine
>>> >>
>>> >>runs:
>>> >> /*
>>> >> =20
>>> >> * Special handling for PXE and CD booting.
>>> >> */
>>> >> =20
>>> >> if (kargs->bootinfo =3D=3D 0) {
>>> >>=09
>>> >> /*
>>> >>=09
>>> >> * We only want the PXE disk to try to init itself in the below
>>> >> * walk through devsw if we actually booted off of PXE.
>>> >> */
>>> >>=09
>>> >> if (kargs->bootflags & KARGS_FLAGS_PXE)
>>> >>=09
>>> >> pxe_enable(kargs->pxeinfo ? PTOV(kargs->pxeinfo) : NULL);
>>> >>=09
>>> >> else if (kargs->bootflags & KARGS_FLAGS_CD)
>>> >>=09
>>> >> bc_add(initial_bootdev);
>>> >> =20
>>> >> }
>>> >>
>>> >>That enables the PXE devsw driver so that it will do something later
>>>when
>>> >>
>>> >>main() calls all the devsw init routines:
>>> >> /*
>>> >> =20
>>> >> * March through the device switch probing for things.
>>> >> */
>>> >> =20
>>> >> for (i =3D 0; devsw[i] !=3D NULL; i++)
>>> >>=09
>>> >> if (devsw[i]->dv_init !=3D NULL)
>>> >>=09
>>> >> (devsw[i]->dv_init)();
>>> >> =20
>>> >> printf("BIOS %dkB/%dkB available memory\n", bios_basemem / 1024,
>>> >>
>>> >>bios_extmem / 1024);
>>
>>--=20
>>John Baldwin
>
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