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giuscri

Member

From: Milan, Italy

Registered: 2013-08-19

Posts: 21

[SOLVED] Booting a linux-embedded from a TFTP-server

Original title: "Knowing IP for a device that has nothing but a bootloader flashed"

Hello,

how can I get the IP for a device that does not have a OS flashed onto it? I mean, I can't use

# ifconfig

and using

# arp-scan --interface=eth0 --localnet

on my Linux box does not return the device which IP I need.

Suggestions?

Thank you,

Giuseppe

Last edited by giuscri (2014-03-05 11:42:43)

forumache

Member

From: Netherlands

Registered: 2011-09-02

Posts: 55

Re: [SOLVED] Booting a linux-embedded from a TFTP-server

If it gets the IP by DHCP, look on the DHCP server and see what IP it allocated.
If you don't have access to the DHCP server, boot one live cd, it will get an IP, look at the IP. Chances are you'll get the same IP when you boot your device the second time, without CD (because the lease is stored on the DHCP server).

giuscri

Member

From: Milan, Italy

Registered: 2013-08-19

Posts: 21

Re: [SOLVED] Booting a linux-embedded from a TFTP-server

If it gets the IP by DHCP, look on the DHCP server and see what IP it allocated.

Apparently no IP is allocated by thre DHCP server. I think it is maybe because only the bootloader starts; I miss a OS an that device.

It is an embedded device, I can't use a live CD.

What I need to do is booting my embedded, then fetching an instance of OpenWrt via a TFTP server that's running on my linux box. But for fetching the OpenWrt img I need the IP of server and client both.

Here's the output

U-Boot 1.1.3 (Nov  3 2009 - 15:19:34)

Board: Ralink APSoC DRAM:  32 MB
relocate_code Pointer at: 81fb0000
flash_protect ON: from 0xBF000000 to 0xBF01D4A3
flash_protect ON: from 0xBF030000 to 0xBF030FFF
============================================ 
Ralink UBoot Version: 3.3
-------------------------------------------- 
ASIC 3052_MP2 (Port5<->None)
DRAM component: 256 Mbits SDR
DRAM bus: 16 bit
Total memory: 32 MBytes
Flash component: 8 MBytes NOR Flash
Date:Nov  3 2009  Time:15:19:34
============================================ 
icache: sets:256, ways:4, linesz:32 ,total:32768
dcache: sets:128, ways:4, linesz:32 ,total:16384 

 ##### The CPU freq = 320 MHZ #### 

SDRAM bus set to 16 bit 
 SDRAM size =32 Mbytes

Please choose the operation: 
   1: Load system code to SDRAM via TFTP. 
   2: Load system code then write to Flash via TFTP. 
   3: Boot system code via Flash (default).
   4: Entr boot command line interface.
   9: Load Boot Loader code then write to Flash via TFTP. 
 3 
You choosed 2

 0 


   
2: System Load Linux Kernel then write to Flash via TFTP. 
 Warning!! Erase Linux in Flash then burn new one. Are you sure?(Y/N)
 Please Input new ones /or Ctrl-C to discard
	Input device IP (10.10.10.12) ==:<IP of my embedded device>
        Input server IP(10.10.10.11) ==:<IP of my linux box>
        ...

alphaniner

Member

From: Ancapistan

Registered: 2010-07-12

Posts: 2,810

Re: [SOLVED] Booting a linux-embedded from a TFTP-server

When you enter an IP on the "Input device IP ..." prompt does that not set the IP of the device?

---

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-Lysander Spooner

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,354

Re: [SOLVED] Booting a linux-embedded from a TFTP-server

If you are doing what I think you are doing, you are doing it wrong

If you are trying to netboot a router to flash it with openwrt, you need to create a simple network on which your Arch box is the dhcp server.  In its simplest form, just plug the router straight into your computer.  Configure the Ethernet as a static address, and configure dhcpcd on the Arch box to make it a dhcp server for the subnet of this little network you have built.  Then set up tftp on you Arch Box and configure it to serve up the image.

Fire up the router in to its net boot mode.  It will ask your Arch box for an address.  Once it has that address, it will turn around and grab the boot image from the tftp server on your box.  Then, you should be able to connect to the device at the address your system provided it.  I use DD-WRT, so at this point, I can browse to it.  I imagine you have to use Telnet or SSH.

Did you see this OpenWRT net boot information?

---

Nothing is too wonderful to be true, if it be consistent with the laws of nature -- Michael Faraday
Sometimes it is the people no one can imagine anything of who do the things no one can imagine. -- Alan Turing
---
How to Ask Questions the Smart Way

giuscri

Member

From: Milan, Italy

Registered: 2013-08-19

Posts: 21

Re: [SOLVED] Booting a linux-embedded from a TFTP-server

Thank you.

This night I've solved this way: since my LAN has only two nodes (and I knew that the DHCP-server assigned 192.168.1.2 to my Linux box) I've solved choosing 192.168.1.42 as the static IP for the client (the embedded device).

At the moment of this writing, issue seems solved.