On Fri, 16 Jul 2010 17:30:01 -0700 Shawn Jin <shawnx...@gmail.com> wrote:
> >> > My RCCR=0x1, meaning the first 512B is for microcode. So the data and > >> > the TxBD should really be starting at 0xfa202200? Then my muram data's > >> > reg should be <0x200 ?>? What size shall I specify? > >> > >> After the muram data's reg is changed to <0x200 0x1a00>, the cpm_uart > >> driver works properly and the kernel messages are printed on the > >> serial port. > > > > The muram node is supposed to show the portions of DPRAM that are > > usable by the OS. If some portion has been taken up by microcode (or > > anything else not under the OS's control) before the OS has started, > > then it must be excluded from the muram node. > > It would be nicer that the initialization code could query the RCCR > value and adjust the base address. Is that the only thing that could possibly conflict with OS usage of DPRAM? It seemed simpler to just specify the usable chunks. Before the kernel supported allocating CPM2 SMC parameter RAM, that was another thing that firmware allocated that had to be kept out of the muram node. > It took me quite a while to understand the design. Sorry... This constraint is described in the MURAM section of Documentation/powerpc/dts-bindings/fsl/cpm_qe/cpm.txt, though. -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
