Hi Martin, On 13 November 2014 03:28, Martin Dorwig <dor...@tetronik.com> wrote: > Am Mittwoch, 12. November 2014, 19:32:21 schrieben Sie: >> Hi Martin, >> >> On 30 October 2014 00:45, Martin Dorwig <dor...@tetronik.com> wrote: >> > Am Mittwoch, 29. Oktober 2014, 13:03:41 schrieben Sie: >> >> Hi Martin, >> >> >> >> On 28 October 2014 07:23, Martin Dorwig <dor...@tetronik.com> wrote: >> >> > Hello, >> >> > after updating u-boot from git v2014.10 >> >> > i just noticed that my standalone application outputs garbage using >> >> > putc. >> >> > after some investigation i found that the gd->jt[XF_putc] is assigned a >> >> > dev->putc pointer in "common/console.c function console_setfile" >> >> > >> >> > the dev->putc is declared in include/stdio_dev.h as >> >> > void (*putc)(struct stdio_dev *dev, const char c); >> >> > >> >> > int include/exports.h this function is declared as >> >> > void putc(const char); >> >> > >> >> > this was introduced with commit id >> >> > 709ea543b92489e7729d2d7ddd6c9f451e52158c >> >> >> >> That's unfortunate. Is the stdio device pointer available in the >> >> standalone application? >> >> >> >> Perhaps gd->jt should point to a structure of strongly-typed >> >> functions? Then we would get a build error in this case. >> >> >> >> Regards, >> >> Simon >> > >> > What is the motivation to override the jumptable slots ? >> > Why can't they be untouched like this >> > gd->jt[XF_getc] = getc; >> > gd->jt[XF_tstc] = tstc; >> > gd->jt[XF_putc] = putc; >> > gd->jt[XF_puts] = puts; >> > redirection of the console to another device is honored in the >> > implementation of the functions themselves. >> > for example the putc function: >> > it calls pre_console_putc before a console is present >> > if GD_FLG_DEVINIT is set, it calls fputc(stdout,c) which calls >> > console_putc(stdout,c) which in turn calls stdio_devices[stdout]- >> > >> >>putc(stdio_devices[file], c); >> >> >> > else it calls serial_putc(c) >> >> I have taken a bit of a look at this. >> >> I have not actually touched the jumptable slots. The one you mention >> was assigned to dev->putc() before and after. The problem is that now >> dev->putc() has two parameters, the first being 'dev'. >> >> dev->putc() is the device's putc function - typically the serial port >> or a display. >> >> The putc() function you mention is the console out, that outputs to >> all stdout devices. >> >> So yes we could change the bahaviour so that it calls putc(). I think >> this will work, and it probably isn't going to result in a change in >> behaviour for many boards since they only have a single stdout. >> >> Alternatively we could require the stdio device parameter to be passed >> in. I'm not sure that will work though - how will the external program >> get at it? >> >> In any case, teh void *gd->jt[] is not serving our purpose here - it >> should be changed to proper function pointer types so that the >> compiler can check that this sort of thing doesn't happen. >> >> Please let me know what you think should be done here. >> >> Regards, >> Simon > > The jumptable is initialized once, and i don't see any reason to overwrite it.
That commit (27b207fd) dates from 2003. Are you wanting to revert an 11-year-old commit or do I misunderstand you? > Adding a parameter to these exported functions will break backward > compatibility > of existing standalone apps Yes that's right, but when they move to a newer U-Boot they will need to be updated. Isn't that expected with standalone apps? I can adjust things that are in the mainline tree, but I can't fix up people's third party apps. I did make a suggestion about how to avoid adding the extra parameter (changing the behaviour to call putc() instead of dev->putc()). What do you think? Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
