On 02/12/2011 19:16, Simon Glass wrote: > It actually started as a last-ditch panic message printer. It morphed > into the general pre-console putc after discussions on the list (with > Graeme). > > It can happen that your early board code does not know what clocks to > use, or can't find a console, or some other critical error. It then > calls panic() which silently dies or maybe reboots if you are lucky. > This problem mostly comes about with device trees, where we must have > certain info in the device tree before we can even get to relocation. > > The idea is that boards provide a way of outputting characters which > tries to work on all types of boards with that SOC. For example, they > output the characters on all UARTs with various clock options, etc. > > We use it on Tegra to print a friendly panic message when something is > horribly wrong. In this case we will never make it to relocation so > the pre-console buffer will not be displayed. So we can't rely on > that.
I do not know if this mechanism can be used on other SOCs, but IMHO it does not hurt and it helps at least on Tegra, as you explained me. Applied to u-boot-staging, sba...@denx.de branch Best regards, Stefano Babic -- ===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: off...@denx.de ===================================================================== _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
