From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Fri, 14 Mar 2008 14:19:29 +0100 Subject: [Buildroot] [PATCH] Add thumb support to buildroot for the ARM architecture In-Reply-To: <47DA7E94.2070302@promwad.com> References: <20080312090846.2cfecec8@crazy> <20080314090331.11f1bddc@crazy> <47DA7E94.2070302@promwad.com> Message-ID: <20080314141929.006a424d@crazy> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Le Fri, 14 Mar 2008 15:33:08 +0200, Ivan Kuten a ?crit : > Thanks for your excellent work! Before committing your patch I have a > question: have you tested it? on which CPU? which buildroot configs? Yes, I tested it using Qemu versatilepb emulation. Enclosed is the buildroot configuration I used. > I'm asking this because for almost half of year I did not managed to > build a good ARM EABI toolchain with buildroot. Toolchain seems emit > invalid instructions when building busybox. So I managed only to run > very simple hello-world when set in cmdline init=hello-world, but not > a busybox binary with shell, etc. Boot process just hangs when > busybox running. Magic-SysRq key shows that illegal instruction trap > was involved. What is surprising that rootfs can be launched ok on > qemu with versatilepb machine emulation, but as I told fails to run > on real hardware S3C2440 CPU - 920T target. I have not tested on real hardware, so I can't say. There might be remaining issues. However, there is quite a big difference between your S3C2440 real hardware and the Qemu versatilepb emulation. S3C2440 is based on 920T as you say, which supports the ARMv4T ISA. But the versatilepb emulation of Qemu emulates an ARM926EJ-S CPU, which supports the ARMv5TEJ ISA. And as far as I understood, there are some differences in the ARM <-> Thumb switch capabilities between ARMv4T and ARMv5T. For what exact CPU did you configure your buildroot ? What was the exact instruction causing the "Illegal instruction" exception ? Sincerly, Thomas -- Thomas Petazzoni, Free Electrons Free Embedded Linux Training Materials on http://free-electrons.com/training (More than 1500 pages!) -------------- next part -------------- A non-text attachment was scrubbed... Name: buildroot-config-with-interworking-and-thumb-applications Type: application/octet-stream Size: 9648 bytes Desc: not available Url : http://busybox.net/lists/buildroot/attachments/20080314/2a9ee424/attachment.obj -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: not available Url : http://busybox.net/lists/buildroot/attachments/20080314/2a9ee424/attachment.pgp