Hi Antony, On Sat, Apr 11, 2015 at 02:22:56AM +0300, Antony Pavlov wrote: > This patchseries adds initial JZ4770 SoC and Ainol Novo7 Paladin tablet support. > > The patchseries can be found on github: > https://github.com/frantony/barebox/tree/20150411.jz4770 > > The most notable problems and todos: > > * no PBL support; I have a PBL-enabled barebox version > for the tablet, so barebox can be used as only bootloader for tablet. > But this version is based on some dirty hacks > e.g. it uses special pre-compiled X-Boot blob for bootstraping. > > Nowadays barebox mips PBL is written in assembler > and I see no way to switch it to C. gcc-4.9.1 for mips has no __naked > directive support, see this gcc output > > $ cat > 1.c <<EOF; > int __attribute__((naked)) __attribute__((no_instrument_function)) main() > { > } > EOF > > $ /opt/mips-2014.11/bin/mips-linux-gnu-gcc -o 1.o 1.c > 1.c:2:1: warning: 'naked' attribute directive ignored [-Wattributes] > { > ^ > > So for moving X-Boot bootstrap C-code into barebox PBL we have to convert it > from C to assembler language :( Is this really necessary? Only the entry point up to the point where you setup the stack needs to be assembly, from then on C can be used. > > Please see JZ4770 bootstrap code in these repos: > > https://github.com/gcwnow/UBIBoot/ > https://github.com/IngenicSemiconductor/X-BOOT_NPM801 > > * no clk support just now; we can easely steal it from linux > JZ4780 support code (see wip-ci20-v4.1 branch in https://github.com/paulburton/linux); > > * no hardware clocksource support; this can be easely fixed, > see linux JZ4780 support code again; > also see https://github.com/frantony/barebox/blob/next.xburst.jz4770.20130511/arch/mips/mach-xburst/csrc-jz4770.c Before merging this series I'd like to have clocksource support. Using the dummy clocksource is fine during initial bringup, but I think merged code should not depend on it. 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
