On Wed, 26 Sep 2012, Stephen Warren wrote:

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.

Let me tell you that this is totally evil.  OMAP and Davinci are doing 
the same abuse.

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,

Please do the later.  That's the only sane solution.

which I don't fancy very much since that's assembly whereas 
uncompress.h is C.

Well, that's too bad.  Time to sharpen your assembly skills.  ;-)


Nicolas