On Tue, Jun 17, 2014 at 09:35:17AM +0400, Antony Pavlov wrote: > On Mon, 16 Jun 2014 23:35:13 +0200 > Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: > > > Hi Antony, > > > > On Mon, Jun 16, 2014 at 09:08:59PM +0400, Antony Pavlov wrote: > > > On Mon, 16 Jun 2014 17:13:54 +0200 > > > Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> wrote: > > > > > > Question to Sascha. > > > > > > Can we preserve the 'memory' dts record in situations like this? > > > > > > Is it possible just alter dts in early init code? > > > Or something else? > > > > For what do you want to preserve it? barebox never uses the memory node > > directly to pass it to the kernel. The barebox memory banks are > > initialized from the code and from the dts. When starting Linux the > > memory node is (re)populated with the barebox memory banks > > > > I may misunderstand what you are trying to archieve. > > Imagine a family of boards. The RAM size can vary from board to board > (for simplicity suppose that all over conditions are the same). > Suppose I have a reliable RAM size detection routine and I want to run > just the same barebox image on different boards. > I want to run dts enabled Linux on all boards. In this case don't specify the memory size in the devicetree. In a mem_initcall detect the actual RAM size you have and call arm_add_mem_device() accordingly. That's all. The rest will be handled automatically. See of_memory_fixup(), this will iterate over the memory banks and set the memory node to the correct values. > > How can I handle this situation correctly? > > Also note that on MIPS boards barebox uses no more than 256 MiB of RAM > (even if a board has more than 256 MiB of RAM). It's a measure to make > mips barebox simplier. > I want to pass information on all available RAM to linux via dts. > Can you describe reasonable barebox behaviour in this situation please? Hmm, not easy. I assumed barebox knows all available memory. What prevents you from registering all memory? I remember MIPS has a cached mapping of the SDRAM. Is this the reason? Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
