On Mon, May 23, 2016 at 10:55:22AM +0200, Alexander Kurz wrote: > Board specific ATAGs might be passed to vendor provided kernels via the > ARM_BOARD_APPEND_ATAG option. In this case, the board specific ATAGs will > be appended to the end of the ATAG list. > Anyway, some vendor provided kernels might crop the ATAG list at ATAG_MEM, > also chopping off the board specific ATAGs, see linux squash_mem_tags() as > reference. The Kindle-3 kernel is one example. > > This conflict might be solved by a) making ATAG_MEM optional which might break > the existing behavour around squash_mem_tags() or b) by allowing the insertion > of board specific ATAGs in front of ATAG_MEM which violates the requirement > from Documentation/arm/Booting to order ATAGs by increasing address. > > Add option to insert board specific ATAGs in front of ATAG_MEM. > > Signed-off-by: Alexander Kurz <akurz@xxxxxxxx> > --- > arch/arm/Kconfig | 10 ++++++++++ > arch/arm/lib/armlinux.c | 8 +++++++- > 2 files changed, 17 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 1fc887b..71374cc 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -313,6 +313,16 @@ config ARM_BOARD_APPEND_ATAG > This option is purely to start some vendor provided kernels. > ** DO NOT USE FOR YOUR OWN DESIGNS! ** > > +config ARM_BOARD_PREPEND_ATAG > + bool "Prepend the board specific ATAGs" > + depends on ARM_BOARD_APPEND_ATAG > + help > + Choose this option if your kernel crops the passed ATAG list e.g. at > + ATAG_MEM, also cropping off the board specific ATAGs. This option > + will pass all board specific ATAGs in front of all other ATAGs. > + This option is purely to start some vendor provided kernels. > + ** DO NOT USE FOR YOUR OWN DESIGNS! ** > + > endmenu > > menu "ARM specific settings" > diff --git a/arch/arm/lib/armlinux.c b/arch/arm/lib/armlinux.c > index 47b9bd3..962d086 100644 > --- a/arch/arm/lib/armlinux.c > +++ b/arch/arm/lib/armlinux.c > @@ -234,6 +234,11 @@ static void setup_tags(unsigned long initrd_address, > const char *commandline = linux_bootargs_get(); > > setup_start_tag(); > +#if defined(CONFIG_ARM_BOARD_APPEND_ATAG) \ > + && defined(CONFIG_ARM_BOARD_PREPEND_ATAG) > + if (atag_appender != NULL) > + params = atag_appender(params); > +#endif You could changle to IS_ENABLED() here to make the code more readable and to increase compile coverage: if (IS_ENABLED(CONFIG_ARM_BOARD_PREPEND_ATAG) && atag_appender) ... (Testing for CONFIG_ARM_BOARD_APPEND_ATAG is unnecessary here since CONFIG_ARM_BOARD_PREPEND_ATAG depends on CONFIG_ARM_BOARD_APPEND_ATAG) > setup_memory_tags(); > setup_commandline_tag(commandline, swap); > > @@ -242,7 +247,8 @@ static void setup_tags(unsigned long initrd_address, > > setup_revision_tag(); > setup_serial_tag(); > -#ifdef CONFIG_ARM_BOARD_APPEND_ATAG > +#if defined(CONFIG_ARM_BOARD_APPEND_ATAG) \ > + && !defined(CONFIG_ARM_BOARD_PREPEND_ATAG) Same here, IS_ENABLED() would be nicer. 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
