On Fri, Apr 19, 2013 at 05:14:36PM +0100, Peter Maydell wrote:
On 19 April 2013 17:12, Catalin Marinas catalin.marinas@arm.com wrote:
On Fri, Apr 19, 2013 at 11:05:47AM +0100, Peter Maydell wrote:
Please make the kernel pick the device out of the device tree blob. The whole point of device tree is that it's how to tell the kernel where things live -- making kvmtool/QEMU and/or the user also have to mess with the kernel command line is awkward and annoying.
For a normal console device, it indeed needs to get it from the DT. For early console, you want it earlier than DT parsing so we pass it on the kernel command line via the earlyprintk= parameter.
You should fix your DT handling code so you can get at the info when you need it rather than pushing the problem into bootloaders and QEMU, please. DT is your data structure so feel free to (re)design it so relevant information can be accessed early if that's useful.
earlyprintk is used for debugging early problems, like DT parsing. You don't have to use it unless you are debugging something. Without earlyprintk you just get a normal console during boot, based on the DT description.