From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Sat, 05 May 2012 13:08:17 +0200 Subject: Development tree for =?UTF-8?Q?Cortex-A=31=35=3F?= In-Reply-To: <1336141827.34227.YahooMailNeo@web132503.mail.ird.yahoo.com> References: <1336046199.46241.YahooMailNeo@web132501.mail.ird.yahoo.com> <1336052155.37772.YahooMailNeo@web132504.mail.ird.yahoo.com> <6e4ad6defa33bf693ec45cae819469f0@localhost> <1336121047.79153.YahooMailNeo@web132504.mail.ird.yahoo.com> <1336141827.34227.YahooMailNeo@web132503.mail.ird.yahoo.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 4 May 2012 15:30:27 +0100 (BST), Jemma Jones wrote: >> Subject: Re: Development tree for Cortex-A15? > >> >> On Fri, 4 May 2012 09:44:07 +0100 (BST), Jemma Jones >> wrote: >>>> Subject: Re: Development tree for Cortex-A15? >>> >>>> >>>> On Thu, 3 May 2012 14:35:55 +0100 (BST), Jemma Jones >>>> wrote: >>>>>> ? Subject: Re: Development tree for Cortex-A15? >>>>> >>>>> ? I'm currently on kvm-arm-v7-ael, because it looked like the >> most >>>>> ? up-to-date one. Which one should I be using for Cortex-A15 >> support? >>>> >>>> That branch is good enough, if you have a bleeding edge QEMU. Note >>>> that >>>> the VE A15 support in that tree is DT only. I'm working on a v3.4 >> based >>>> one >>>> at the moment, but that's not completely ready yet. >>> >>> I'm just a little confused because under arch/arm/mach-vexpress/ there >> is >>> no A15 tile? On the virtualopensystems.com git (which you quote above) >> you >>> had to explicitly enable the board and it would show up in the .config >> as >>> CONFIG_ARCH_VEXPRESS_CA15X4. Is that not the case anymore in your >>> kernel >>> tree? >> >> No. The ARM tree in general is moving to the device tree, and >> CONFIG_ARCH_VEXPRESS_CA15X4 was always meant as a temporary hack until >> the >> VE-DT port was mature enough to be used. >> >> As Pawe?'s DT work has been merged into 3.4, there is strictly no reason >> to keep this hack around, and my recent trees do reflect that fact >> (kvm-arm-v7-ael and kvm-arm-3.4). Christoffer may decide to keep this in >> his tree during a transition period, but CONFIG_ARCH_VEXPRESS_CA15X4 is >> dead as far as I am concerned. >> >> If you're just starting to play with KVM-ARM now, please don't rely on >> the >> A15 board file, it is a dead end. > > What would be the correct configuration of low-level kernel debugging for > the A15 board? I'd like to have earlyprintk etc working. > > When I set it to > Kernel low-level debugging port (No low-level debugging UART) > > then I get the following error: > > $ ARCH=arm make uImage > scripts/kconfig/conf --silentoldconfig Kconfig > # > # configuration written to .config > # > ? CHK???? include/linux/version.h > ? CHK???? include/generated/utsrelease.h > make[1]: `include/generated/mach-types.h' is up to date. > ? CALL??? scripts/checksyscalls.sh > ? CHK???? include/generated/compile.h > ? AS????? arch/arm/kernel/debug.o > In file included from arch/arm/kernel/debug.S:104:0: > arch/arm/mach-vexpress/include/mach/debug-macro.S:26:2: error: #error > "Unknown vexpress UART offset" > make[1]: *** [arch/arm/kernel/debug.o] Error 1 > make: *** [arch/arm/kernel] Error 2 Known problem with this kernel tree, fixed in kvm-arm-3.4. > If I just disable > [*] Kernel low-level debugging functions > then I don't seem to get any output at all. Because your kernel is probably crashing before the console is enabled. > What is the correct configuration? First, we have to understand why your kernel is crashing, and I have the strong feeling it is DT related. I'm really curious of what dts file you're using when building your uImage... M. -- Fast, cheap, reliable. Pick two.