Re: Boot hang when setting console=none with MPC5200B custom board
[snip] > Can you halt the processor with JTAG and look at the contents of __log_buf? Ok I'll try that as soon as I can get CodeWarrior to work again... > > 1. Is it possible ? > > Yes, I believe so, but I haven't tried. Ok > > > 2. Do you have any idea how it can be achieve ? > > You should be doing the right thing. Are your userspace init scripts > trying to start a getty on the non-existent console device? > Nope and using init=/bin/sh gave me /bin/sh: can't access tty; job control turned off And then / # tty not a tty Is helpful ? This is while using console=ttyS1,115200 (so when I know it's working) > > 3. Do you know a bug in 2.6.29.2 that could prevent this to work ? > > no Ok :) > > > 4. The 'chosen' node is empty in my dts, does it require something to be > > set ? > > no Good to know > > I think your best bet is to figure out some way to get at __log_buf to > retrieve the kernel output after the failed boot. Ok I'll try to revive CodeWarrior (I would better appreciate a BDI2000, but I'm stuck with a Freescale USB TAP that require CodeWarrior) > > Cheers, > g. > Thank you Sylvain ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: Boot hang when setting console=none with MPC5200B custom board
Hi Albrecht, > > 1. Is it possible ? > > Yes! I tried this with several kernel versions (currently 2.6.33), using the > option 'console=tty0'. Works just fine... > Happy to know that it can be done ! > > 2. Do you have any idea how it can be achieve ? > > Hmmm, iirc, I also saw the effect you have. I *think* the solution was to > ensure that all /dev/* files were created manually in the jffs image, not by > running mdev (if you use busybox). But I might be wrong here, sorry. Being > at home, I don't have access to the device, but I can re-check tomorrow. > Humm I see, here is the node I'm creating in the initial ramdisk, so they are there before mdev is launched in one of my init scripts. console c 5 1 null c 1 3 zero c 1 5 ptmx c 5 2 tty c 5 0 randomc 1 8 urandom c 1 9 initrdb 1 250 ram0 b 1 0 ram1 b 1 1 ram2 b 1 2 ram3 b 1 3 ramdisk -> ram0 ram -> ram0 loop0 b 7 0 loop1 b 7 1 I think I have all the necessary device for boot, but if you could double check with yours I would appreciated it. > > 3. Do you know a bug in 2.6.29.2 that could prevent this to work ? > > Not sure if I used *exactly* that version w/o serial console, but (iirc) > 2.6.28.something, and then many different up to .33 - they all work! Ok > > Best, Albrecht. Thank you Sylvain ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Boot hang when setting console=none with MPC5200B custom board
Hi everybody, I'm trying to remove the console from a custom board based on a MPC5200B. During development we used console=ttyS1,115200 in our bootcmd for the kernel, but now that the product is ready to be shipped we want to use ttyS1 for something else and would like to deactivate completely the console. So the unit would be accessible only by ssh if needed. (I'm not really confortable with this since a network problem would prevent us of even debugging the platform... but I've been ask to do it.) Anyway, whenever I try to change console= to null or to tty1 or anything else, the boot is hanging somewhere ( I know that, because some leds are not flashing like they should on a normal boot and I can't login in with ssh). I've tried to use tty1, none, null, zero and I've tried to completely remove the console= arguments... but nothing work, its hanging there without any flashing leds. I've tried redirecting another "real" serial port and it worked, so console=ttyPSC2,115200 work... but we need it also... so it can't do. I've also tried the U-Boot's silent variable trick ... but it did not work and I had to erase the environment of U-Boot with a JTAG to recover back my default setting of ttyS1. I'm now at a point where I think I have try everything that I know, and since I have no way of "seeing" what is going on ... it's pretty hard to debug. The kernel is 2.6.29.2 and can't really be changed... (but it may be patch) This board doesn't have a framebuffer or a graphic chipset, everything was done with a serial connection and now we want to remove this serial connection (console) before sending it to a customer. 1. Is it possible ? 2. Do you have any idea how it can be achieve ? 3. Do you know a bug in 2.6.29.2 that could prevent this to work ? 4. The 'chosen' node is empty in my dts, does it require something to be set ? Thank you for your help ( I hope ;) ) Sylvain Lamontagne ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Need advice on changing MPC5200B UART prescaler
Hi all,
I would like to be able to set a baud rate of 460800 for modem that we are
testing. With the actual prescaler of 32 and a IPB frequency of 84MHz
I got a 5.1% error (437500) vs a 0.9% error (456522) if I could use the
prescaler of 4. See MPC5200B user manual page 15-46 for the calculation
formula and page 15-12 for the CSR description.
Currently the code for the kernel we are using here, (2.6.29.2) seams not to
take a prescaler of 4 into account.
Line 249 of mpc52xx_uart.c
http://lxr.linux.no/linux+v2.6.29.2/drivers/serial/mpc52xx_uart.c#L249
/* Search for bus-frequency property in this node or a parent */
static unsigned long mpc52xx_getuartclk(void *p)
{
/*
* 5200 UARTs have a / 32 prescaler
* but the generic serial code assumes 16
* so return ipb freq / 2
*/
return mpc52xx_find_ipb_freq(p) / 2;
}
How could I make it use the prescaler of 4 without breaking anything that we
currently have working ?
I doubt that simply doing return mpc52xx_find_ipb_freq(p) / 4 would do the
trick ...
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Installation on a MPC5200 based custom board
Greetings We are currently trying to put a Kernel 2.6.26 on a custom board based on the MPC5200 processor and the designed of the board was based on the lite5200b evaluation board. We would like to have some advice regarding the installation process for this kernel. The hardware currently work (still buggy, but work) with a kernel 2.6.23 compiled with ARCH ppc running on a U-Boot 1.1.6. For what I understand now, the ARCH ppc if kind of deprecated and we have to switch to ARCH powerpc. I'm new to the concept of device tree, do I have to modify it myself or the file wild be generated automatically ? Should it be better for us to upgrade our version of U-Boot to 1.3.* to get the support of device tree? Currently we tried with the wrapper trick of using cuImage.lite5200b and the v1.1.6 but it doesn't seem to work. Also, we would like to know if we have to recompile everything on the board (U-Boot/Kernel/Busybox) since we switched ARCH from ppc to powerpc? We are also wondering what is the cross-compilation tools that you are using? Or do you have any good advice on a choice? Currently we are building with gcc-4.1.0-glibc-2.3.6 for ppc on an x86 host running Ubuntu 8.04 or we also have a Fedora Core 7 laptop but, I have see a kernel compilation warning regarding gcc 4.1 saying that it's known to brake the kernel. Should we upgrade everything (U-Boot/Kernel/Busybox) and recreate a new Ramdisk ? Anybody know a good development tools to use with a CodeWarrior USB TAP from freescale ? The CodeWarrior IDE doesn't seems to work properly for us. This is a lot of questions and they maybe unclear since I'm new to all this, but if you need any more information I can provide them. Best Regards, -- Sylvain Lamontagne Software Developer Novariant Canada Ext.: 4940 ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
