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. Adding a parameter to these exported functions will break backward compatibility of existing standalone apps Regards, Martin _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
