Hi Vasili, On 29 April 2015 at 10:57, Vasili Galka <vvv...@gmail.com> wrote: > Hi Tom, > > I’m working on rebasing an old U-Boot branch for our company’s AM335x > based board upon the current U-Boot release (v2015.04). Our branch was > initially based on the v2013.10 release (the ti/am335x/ board was > taken as reference). > > After making all the code compile, I discovered there was a change in > the U-Boot initialization sequence, introduced by commit > a6b541b09022acb6f7c2754100ae26bd44eed1d9, that prevents our code from > working: > > Prior to the above mentioned commit, the console serial port was > initialized at a very early stage in the armv7/am335x/board.c:s_init() > function (calling preloader_console_init()). Roughly saying, it was > the first thing done by the SPL code. This made quite much sense, as > it enabled all the code afterwards to output status/debugging info to > the console. > Moving the preloader_console_init() call to spl_board_init() caused it > to be run at a very "late" stage (as part of the board_init_r() > function). AFAIU, now all the code that runs till then has no ability > for any console output. > For example, in our particular case, the DDR configuration code (in > sdram_init()) reads the DDR type from an I2C EEPROM. Obviously, if > something goes wrong in this process, we would like to report it to > the console. > > I understand there was a good reason for the mentioned commit (the > GD), however, as you see, we have also lost some important > functionality with it. I would appreciate your advice on how to solve > it.
It would certainly be very useful and it would be great if we could printf() from as soon as we have a stack (and perhaps printch() even earlier). I think it can be done, but I have not put in the time to figure it out. You could take a look at CONFIG_DEBUG_UART which at least allows primitive UART access before gd is set up. I wonder if we could do something like change printf() /purchatr() to use this when gd is NULL? Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
