Best Regards! Anson Huang
> -----Original Message----- > From: Arnd Bergmann [mailto:a...@arndb.de] > Sent: 2016-08-26 4:59 PM > To: Yongcai Huang <anson.hu...@nxp.com> > Cc: linux-arm-ker...@lists.infradead.org; devicet...@vger.kernel.org; linux- > ker...@vger.kernel.org; shawn...@kernel.org; ker...@pengutronix.de; > Fabio Estevam <fabio.este...@nxp.com>; robh...@kernel.org; > mark.rutl...@arm.com; li...@armlinux.org.uk > Subject: Re: [PATCH 3/3] ARM: imx: add SMP support for i.MX7D > > On Friday, August 26, 2016 7:12:51 PM CEST Anson Huang wrote: > > i.MX7D has 2 cortex-a7 ARM core, add support for booting up SMP kernel > > with 2 CPUs. > > > > The existing i.MX SMP code is designed for i.MX6 series SoCs which > > have cortex-a9 ARM core, but i.MX7D has 2 cortex-a7 ARM core, so we > > need to add runtime check for those differences between cortex-a9 and > > cortex-a7. > > > > Signed-off-by: Anson Huang <anson.hu...@nxp.com> > > > > Can't you just point i.MX7D to start from secondary_startup rather than > v7_secondary_startup? > > ENTRY(v7_secondary_startup) > + .word 0xc070 @ 0xc07 is cortex-a7 id > + .word 0xfff0 @ mask for core type > + > > This looks like you are trying to execute instructions that are actually > data. Does > this work? > > On a side note, could you rename v7_secondary_startup to > imx6_secondary_startup? The name sounds overly generic on a multiplatform > kernel. > > Arnd Thanks for review, yes, I made a mistake here, the data should put in another place, but it accidently can work and boot up secondary CPU (see below the objdump), and also, I can just use secondary_startup for i.MX7D. So I will leave this file untouched, will verify the function next Mon and send out a V2 patch. 10 00000004 <v7_secondary_startup>: 11 4: 0000c070 andeq ip, r0, r0, ror r0 12 8: 0000fff0 strdeq pc, [r0], -r0 Anson.
