On 2014-12-17 13:31, Arnd Bergmann wrote: > On Wednesday 17 December 2014 00:41:33 Stefan Agner wrote: >> On 2014-12-03 12:03, Arnd Bergmann wrote: >> > On Wednesday 03 December 2014 01:12:10 Stefan Agner wrote: >> >> diff --git a/arch/arm/boot/dts/vf610m4-colibri.dts b/arch/arm/boot/dts/vf610m4-colibri.dts >> >> new file mode 100644 >> >> index 0000000..051ee0f >> >> --- /dev/null >> >> +++ b/arch/arm/boot/dts/vf610m4-colibri.dts >> >> @@ -0,0 +1,52 @@ >> >> +/* >> >> + * Device tree for Colibri VF61 Cortex-M4 support >> >> + * >> >> + * Copyright 2014 Stefan Agner >> >> + * >> >> + * This program is free software; you can redistribute it and/or modify >> >> + * it under the terms of the GNU General Public License as published by >> >> + * the Free Software Foundation; either version 2 of the License, or >> >> + * (at your option) any later version. >> >> + */ >> >> + >> >> +/dts-v1/; >> >> +#include "vf610m4.dtsi" >> >> + >> >> +/ { >> >> + model = "VF610 Cortex-M4"; >> >> + compatible = "fsl,vf610m4"; >> >> + >> >> + chosen { >> >> + bootargs = "console=ttyLP2,115200 ihash_entries=64 dhash_entries=64 earlyprintk clk_ignore_unused init=/linuxrc rw"; >> >> + }; >> >> + >> > >> > Starting with v3.19, you should be able to use the earlycon framework on >> > arm32, so it would be better to replace earlyprintk with earlycon here >> > and add a stdout-path property in chosen that points to the console >> > uart. >> >> I started to implement earlycon support, but something currently fails >> when earlycon tries to map the UART registers: >> [ 0.000000] earlycon_map: Couldn't map 0x40027000 >> >> I traced the issue a bit further down and found that get_vm_area_caller >> returns NULL (in __arm_ioremap_pfn_caller). This happend on Linus master >> as of today (2dbfca5a181973558277b28b1f4c36362291f5e0). Do I miss >> something here? > > Hmm, I fear the arm32 FIX_EARLYCON_MEM support ended up not making it > into 3.19 after all. :( Is it because early_ioremap and fixmap still missing for arm32? According to Rob's patchset from spring fixmap is required, there is something in this tree: https://git.kernel.org/cgit/linux/kernel/git/robh/linux.git/log/?h=arm-fixmap -- Stefan -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html