Dear Wolfgang,
Am Mittwoch, 27. April 2011, 21:08:50 schrieb Wolfgang Denk:
In message 201104271759.11818.alexander.stein@systec-electronic.com you
wrote:
Setting stdin, stdout and stderr takes a lot of time (IIRC ~500ms). Which IMO is useless on a bootloader without LCD support.
Statements like this are completely worhtless if you don;t tell exactly on which architecture and board, and with which exact version of U-Boot such numbers have been measured.
Ok, let me be more precise on this. We used U-Boot v2010.09 on a custom board running on an I.MX35 (ARM1136). We noticed the following code snippet took relatively long. From common/console.c in console_init_r(void):
/* Setting environment variables */ for (i = 0; i < 3; i++) { setenv(stdio_names[i], stdio_devices[i]->name); }
We added PIN toggling around this part of code and measured something >100ms. A collegue said it was ~100ms, I remembered ~500ms. Dunno who is right.
Regards, Alexander