Date: Wed, 17 Feb 2021 12:21:48 -0300 From: Dr. Rolf Jansen <freebsd-rj@obsigna.com> To: freebsd-arm <freebsd-arm@freebsd.org> Subject: Re: LLDB on FreeBSD/arm64 and arm Message-ID: <6FAC63F4-79D8-4D25-BC29-44371303A09B@obsigna.com> In-Reply-To: <c6f9e733-627d-377c-84c4-22c7f12aec8f@gmail.com> References: <CAPyFy2A_E=fJwbRoL4uj4PvyeQ_Oz0v1xTOw3tkTQvJNfO3LbQ@mail.gmail.com> <E2CC3F9F-75DE-41F5-83BD-0179007583C2@obsigna.com> <fd58349e0b352636a8444418227b9ea5318360da.camel@gentoo.org> <9EDAF212-EA86-4AAC-97C6-BB801161DC4D@obsigna.com> <c6f9e733-627d-377c-84c4-22c7f12aec8f@gmail.com>
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Am 16.02.2021 um 11:01 schrieb Michal Meloun <meloun.michal@gmail.com = <mailto:meloun.michal@gmail.com>>: > On 16.02.2021 14:34, Dr. Rolf Jansen wrote: >> Am 05.02.2021 um 13:40 schrieb Micha=C5=82 G=C3=B3rny = <mgorny@gentoo.org>: >>> On Fri, 2021-02-05 at 12:30 -0300, Dr. Rolf Jansen wrote: >>>> Am 03.02.2021 um 14:53 schrieb Ed Maste <emaste@freebsd.org>: >>>>=20 >>>>> As you may know, the FreeBSD Foundation sponsored Moritz Systems = to >>>>> improve LLDB's support of non-x86 FreeBSD targets (and some other >>>>> improvements applicable to all targets). This builds on their >>>>> earlier >>>>> work to update x86 support. >>>>>=20 >>>>> Initial changes for arm64 and arm support were recently committed >>>>> upstream. Details are in these code reviews, if you're interested: >>>>>=20 >>>>> https://reviews.llvm.org/D95297 (arm64) >>>>> https://reviews.llvm.org/D95696 (arm) >>>>>=20 >>>>> arm and arm64 users with an interest in LLDB are encouraged to = build >>>>> LLDB from the upstream git repository, try out the support, and >>>>> report >>>>> issues or positive results. >>>>>=20 >>>>> It should build using the regular build process as described at >>>>> https://lldb.llvm.org/resources/build.html >>>>>=20 >>>>> At present all four of 32- and 64-bit arm and x86 use LLDB's >>>>> non-legacy debug support by default. Legacy support will be = removed >>>>> from LLDB upon completion of Moritz' work (once all architectures >>>>> are >>>>> patched) and there is no need to try out legacy support. >>>>=20 >>>> I am interested to build LLDB from the upstream repository. As a >>>> matter of fact a few years ago I did this already directly on a >>>> BeagleBone Black, however in the meantime the LLVM sources had = grown >>>> beyond the capacity a BBB could compile. Already at that time a = rather >>>> limited build took more than 48 hs. >>>>=20 >>>> I set up an ARMv7 cross building environment for kernel and world = on a >>>> reasonably equipped i7 machine. Can I somehow use this for building >>>> LLDB as well? >>>=20 >>> Yes. See our summary for some tips: >>>=20 >>> = https://www.moritz.systems/blog/freebsd-remote-process-plugin-on-non-x86-a= rchitectures/ >>>=20 >>> Go for 'Cross-compiling LLVM'. On ARMv7, you'll have to change >>> the target and host triplets to armv7-unknown-freebsd13.0-gnueabihf >>> and LLVM target to ARM. >>>=20 >>>> I provided ssh root access to one of my BBBs to Micha=C5=82 G=C3=B3rn= y for >>>> testing his work, and he left a LLDB on the system, I don't know at >>>> which stage, though. When debugging an advanced project of mine = with >>>> this one I see some show stoppers (as with the original LLDB). >>>> Perhaps, I could be of help to improve LLDB. >>>=20 >>> If it's about watchpoints, then we need to support them on kernel = level >>> first. For anything else, we need to figure out what's = wrong/missing. >> It took a while until I got it working - =E2=80=9Etoo many variables, = so few time=E2=80=9C >> In the toolchains file, I needed to add a definition for sysroot. = When passing it with the C_FLAGS and CXX_FLAGS, I got typical 32 vs. 64 = bit errors very early in the build process. Something like size_t is not = long. The working toolchain file for ARMv7 is the following =E2=80=94 = <SYSROOT> is the placeholder for the actual path, here it is = /root/install/BBB/sysroot: >> set(CMAKE_C_FLAGS "-target armv7-unknown-freebsd13.0-gnueabihf") >> set(CMAKE_CXX_FLAGS "-target armv7-unknown-freebsd13.0-gnueabihf") >> set(CMAKE_SYSROOT <SYSROOT>) >> set(CMAKE_SYSTEM_NAME "FreeBSD") >> set(CMAKE_FIND_ROOT_PATH <SYSROOT>) >> set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER) >> set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY) >> set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY) >> Before, I found this out, I meandered between versions of LLVM (I = compiled 10.x, 11.x, 12.x and HEAD), and I switched to another build = machine, before it was FreeBSD 12.2-RELEASE on a real i7 and now I build = in a VM running FreeBSD 13.0-BETA2. However, without the definition of = CMAKE_SYSROOT all this did not work out. >> Now I deployed a lldb to my BeagleBone running 13-BETA2 as well: >> lldb version 13.0.0 (https://github.com/llvm/llvm-project.git = revision b40fde062c306584d88243de11175187e754ce3b) >> clang revision b40fde062c306584d88243de11175187e754ce3b >> llvm revision b40fde062c306584d88243de11175187e754ce3b >> I am able to debug simple programs, but the happiness ends already = when trying to enter a subroutine. At least this worked well with lldb = 11.0.1, which has been build by using in the course of world by = WORLD_FLAGS=3D"MK_LLDB=3Dyes=E2=80=9C. However both bail out, when I try = to debug a bigger project of mine. >> (lldb) target create "./CyDaemon" >> Current executable set to '/root/install/CyDaemon/CyDaemon' (arm). >> (lldb) settings set -- target.run-args "-f" "-l" "80" "-s" "443" >> (lldb) r >> Process 767 launched: '/root/install/CyDaemon/CyDaemon' (arm) >> Process 767 stopped >> * thread #1, name =3D 'CyDaemon', stop reason =3D signal SIGILL: = illegal instruction >> frame #0: 0x20290048 >> -> 0x20290048: vmull.p64 q0, d0, d0 >> 0x2029004c: bx lr >> 0x20290050: ldr r0, [pc, #0x68] >> 0x20290054: add r1, pc, #100 >> (lldb) >> The question now is, how to continue from here? Do we continue? If = yes, do we build on FreeBSD 13.0-RELEASE (BETAx for some more days) or = do we build on 14-CURRENT? Which version of lldb do we debug? A release = version or HEAD? >> The last lldb which worked absolutely well on the BBB was 3.9 or was = it 4.x. I know, that I never got 5.x to compile on the BBB. However now, = that my cross-building environment has been set up, I probably will = check that as well. >> Best regards >> Rolf >=20 > Hi Rolf, > This is quite normal behavior.. Your program uses crypt library ant = this library determines presence of crypto extension instructions = (Cortex A9 have not these). The library have SIGILL signal handler = installed and if vmull instruction is not supported it switches to pure = sw mode. In this case do nothing else press continue... OK, this make sense. Actually, I need to continue 5 times. Now I pass a = startup script file on the lldb command line so it skips this annoyance = automatically: -s lldbstartup run process handle -n false -p true -s false SIGILL continue I now compiled release/11.x and this works well, except the longstanding = issue, by which lldb in the GUI loses the focus when stepping through a = threaded program =E2=80=94 see = https://lists.llvm.org/pipermail/lldb-dev/2017-November/012954.html = <https://lists.llvm.org/pipermail/lldb-dev/2017-November/012954.html>; Anyhow, this thread is about testing new features which made it into = LLDB for FreeBSD arm[64|], and my question remains, where did these = additions landed (main?, release/12.x?, release/11.x?) and what would I = test? Best regards Rolf=
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