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Although I am surprised by your finding, I do program exclusively in LXRT. In my opinion it seems much more straight-forward to write in user space (I don't have 10usec requirements, however). What do you get when you run the testsuite latency programs? Most computers I've seen do a better job with the kernel latency program... but I don't recall what the TS board does. I'll have to test it when I get a chance.
So, the jitter of about 10us that I saw wasn't a oscilloscope problem. Unfortunately, it was caused by RTAI. But I found something very interesting: when I code the same program in the user-space, the older was coded to be a kernel module, I could achieve a jitter less the 5us! So I realized what I need right now: to know some good practices in RTAI programming :) Does anyone can give me some advice? Thanks, Ronan. --- In "ronis_br" <> wrote: > > Hi everyone, > > First of all, I would like to thanks everyone who have helped me! > > I finally could make RTAI works! The problem: I used a wrong gcc version to compile the kernel. I was using gcc-3.4.4 but the TS 2.4 kernel must be compiled with gcc-3.3. After this, everything works fine. > > Now I'm testing RTAI. > > I'm beginner in kernel modules programing so I need some help. > I realized that I couldn't use the functions open, mmap and so that TS uses in examples to access the registers. Than I found that I can do this using the function outb(value, address). Everything works fine, but is this the right thing to do? > > I could construct the wave form that I want, but I'm seeing on oscilloscope some oscillation of about 20us that happen randomly. I can't really say if it is because RTAI or the oscilloscope problem. I'm investigating and when I have a conclusion I'll post here. > > Some interesting point: to test RTAI, I maid a square wave by software (a kernel module). I saw that if the period of this wave is less than 50us, approximately, than the system locks :D The wave continues to be executing, but there is seems to be no more time to linux tasks, so I can't use it anymore by serial. > > Thanks everyone one more time, > Ronan. > > --- In sjanisch@ wrote: > > > > I didn't set support for JFFS2. Isn't that more of a file system entry > > (I'm not a real linux expert by any means... more of a hack than > > anything)? > > > > The flash stuff that I was talking about was in this section > > # > > # Memory Technology Devices (MTD) for 2k NAND flash > > # > > CONFIG_MTD2K=y > > # CONFIG_MTD_DEBUG is not set > > CONFIG_MTD_PARTITIONS=y > > # CONFIG_MTD_CONCAT is not set > > # CONFIG_MTD_REDBOOT_PARTS is not set > > # CONFIG_MTD_CMDLINE_PARTS is not set > > # CONFIG_MTD_AFS_PARTS is not set > > CONFIG_MTD_CHAR=y > > CONFIG_MTD_BLOCK=y > > # CONFIG_FTL is not set > > # CONFIG_NFTL is not set > > # CONFIG_INFTL is not set > > > > Assuming the 7260 and 7250 use the same flash (which I couldn't tell > > you)... this was the missing step in getting the flash to work. > > > > But I think they do. The TS-7200 lists the flash as NOR flash, while the > > 7250 and 7260 list NAND flash. > > > > From what I understand, this is the actual driver that allows the kernel > > to read the flash... > > > > I'll send the complete .config file to your gmail account... note that it > > was for the 7250 rather than the 7260, but the two appear pretty close in > > terms of specs. > > > > > > wrote on 08/03/2009 01:59:24 PM: > > > > > With your procedures, I could compile the kernel correctly, but I > > > just can do it when I disable the support for CONFIG_JFFS2_FS_NAND. > > > But the system cannot boot correctly if I have this option disable in > > kernel. > > > > > > When I try to compile it with NAND support for JFFS2 enable, than I > > > get the following error: > > > ------------------------------------ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/ts-7000/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/ts-7000/join (Yahoo! ID required) <*> To change settings via email: <*> To unsubscribe from this group, send an email to: <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/ __._,_.___
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