Booting linux in PowerPC board

[guru1132]

Hi

I have a PowerPC COTS board from Embedded Planet.

Using the manual supplied with the board I was able to configure the uboot parameters and load the kernel , ramdisk image and DTB into the flash.

But after booting it with bootargs as root=/dev/ram rw console=ttyS0,115200 nothing appears in my teraterm after uboot messages of loading the kernel,ramdisk and DTB.

Can someone guide me in probing the issue?

[atreyu]

Hello and welcome!

But after booting it with bootargs as root=/dev/ram rw console=ttyS0,115200 nothing appears in my teraterm after uboot messages of loading the kernel,ramdisk and DTB.

1. So you are saying that text DOES appear in your teraterm (via serial cable) up until a certain point, then nothing more appears?
   
   
2. Has any login program (e.g, mingetty) been configured on the embedded system to listen on that device? (often defined in /etc/inittab or other rc.init startup file)
   
   
3. Is there a VGA (or other display) port on the device to which you can connect a monitor to see if there a console is attached there?

[guru1132]

Hello and welcome!

1. So you are saying that text DOES appear in your teraterm (via serial cable) up until a certain point, then nothing more appears?

yes. You are correct.I read somewhere that TEXT is the last Uboot message.I have copied the text below.Am I correct?

WARNING: adjusting available memory to 30000000
## Booting kernel from Legacy Image at ffc00000 ...
Image Name: Linux-2.6.36-rc2-ep3.01
Image Type: PowerPC Linux Kernel Image (gzip compressed)
Data Size: 2038641 Bytes = 1.9 MB
Load Address: 00000000
Entry Point: 00000000
Verifying Checksum ... OK
## Loading init Ramdisk from Legacy Image at f8000000 ...
Image Name: Linux RAMdisk Image
Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
Data Size: 4200214 Bytes = 4 MB
Load Address: 00000000
Entry Point: 00000000
Verifying Checksum ... OK
## Flattened Device Tree blob at fff00000
Booting using the fdt blob at 0xfff00000
Uncompressing Kernel Image ... OK
Loading Ramdisk to 2fbfe000, end 2ffff716 ... OK
Loading Device Tree to 00ffa000, end 00fff0f6 ... OK

1. Has any login program (e.g, mingetty) been configured on the embedded system to listen on that device? (often defined in /etc/inittab or other rc.init startup file)

I checked that .No getty program is configured.But init is configured to open busybox shell. Does'nt the kernel messages be printed before getty?

Also I tried telnet login by puTTY. I think it doesnot require any getty program.But my puTTY closes after few seconds.

1. Is there a VGA (or other display) port on the device to which you can connect a monitor to see if there a console is attached there?

No .there is not any Display port.
Thank You

[atreyu]

yes. You are correct.I read somewhere that TEXT is the last Uboot message.I have copied the text below.Am I correct?

I'm not sure I understand your question.

No getty program is configured.But init is configured to open busybox shell.

Busybox has a getty applet itself. Anyway, unless you built this embedded OS yourself, there is probably some getty program on there. And it has to listen on some device (such as ttyS0, etc.). You can run the busybox command by itself, and it should spit out all the currently built-in applets (assuming you can boot up at all, like on another board or something).

Does'nt the kernel messages be printed before getty?

Yes, but after the kernel boots up, it executes init, which usually calls some rc script and/or /etc/inittab. and one of those, in turn, usually fires up login programs (like login, getty, mingetty, etc.).

Redirection over serial is tricky, there are two or three parts. The very first part is the BIOS: some BIOSes allow redirection of the POST over serial port. Forget about that for now. Next comes the boot-loader (grub, lilo, etc.), you can direct that (and thus the kernel boot portion) over a serial device. Lastly comes serial logins to the Linux system, once it is up. This is achieved using one of those getty programs listening on your serial device (ttyS0, ttyUSB0, etc.).

Also I tried telnet login by puTTY. I think it doesnot require any getty program.But my puTTY closes after few seconds.

That assumes that networking is up and you have an ip address configured? Is this so? If you think the system is booted up, nmap it from another Linux box to see what network services might be running, e.g.:

nmap -n <ip_of_embedded_device>

You might need to install nmap first (yum install nmap, sudo apt-get install nmap, etc.).

[guru1132]

hi

The reason for the issue has been found out.

I have used a 36bit memory map uboot with a 32 bit linux BSP. I have asked the vendor for a 36 bit BSP.
Hope I can boot with the new BSP.

Thanks for your support and guidance.

[atreyu]

I have used a 36bit memory map uboot with a 32 bit linux BSP. I have asked the vendor for a 36 bit BSP.
Hope I can boot with the new BSP.

Wouldn't it be easier to use a 32bit memory map uboot and a 32bit linux BSP? Anyway, glad you found the problem and good luck!

If you have more questions/issues regarding this topic, please post them. Otherwise, you can mark this thread as Solved using the Thread Tools at the top of the page.

[guru1132]

Wouldn't it be easier to use a 32bit memory map uboot and a 32bit linux BSP? Anyway, glad you found the problem and good luck!

If you have more questions/issues regarding this topic, please post them. Otherwise, you can mark this thread as Solved using the Thread Tools at the top of the page.

what exactly does it mean by 32 bit memory map uboot and 32 bit kernel? if it is complex please direct me any links.

Thank you.

[atreyu]

what exactly does it mean by 32 bit memory map uboot and 32 bit kernel? if it is complex please direct me any links.

I just assumed a 32-bit uboot file and a 32-bit board would be easier than mixing and matching, or using 36-bit anything.