On 09/26/2012 09:10 AM, Russell King - ARM Linux wrote: > On Wed, Sep 26, 2012 at 02:49:48PM +0000, Arnd Bergmann wrote: >> Right now, a multiplatform kernel has no way of debugging the >> decompressor using console output, so it's actually /smaller/ >> than a single-platform kernel, but also less capable. > > Err, are you sure about all your details above? You do realise when > debugging is disabled there is no debug code included anywhere in the > decompressor? > > I think what you're referring to is not the debug output, but the normal > decompressor output. (The "Decompressing Linux..." message is not > debug output.) > > Let's be a little more clear about what "less capable" means - it will > be unable to report any errors that occur during the decompression. > What that means is that you'll end up with mere silence should an > error occur. In the Tegra case, by omitting uncompress.h, we lose more than just the "Decompressing Linux..." message; uncompress.h contains code to parse extract the platform's debug UART ID from data set up by the boot ROM (since we have 5 UARTs), and pass this on to debug-macro.S. Without uncompress.h running, debug-macro.S would either have to hard-code a single UART ID (and different boards uses different UARTs, which would make running a single kernel image across all Tegra devices with earlyprintk enabled impossible) *or* we'd have to port the UART ID extraction code to debug-macro.S too, which I don't fancy very much since that's assembly whereas uncompress.h is C. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
