Thanks, Omair. I did check xml files in Linaro's source (gdb-linaro-7.6.1-2013.10). In the target.xml file our gdb server sends back to gdb client, we only include regsiters X0~X30, sp, pc and cpsr. It's close to gdb-linaro-7.6.1-2013.10\gdb\features\aarch64-core.xml, which is included in aarch64-without-fpu.xml. I don't know how the server can notify the client that it does not have FPU supported. So I assume if the target.xml does not claim feature 'org.gnu.gdb.aarch64.fpu’, it would be deemed as no FPU supporting. For now, I added some code in our code to return the value of fpsr and fpcr to make the gdb client happy.
Regards, Strong -----Original Message----- From: Omair Javaid [mailto:omair.jav...@linaro.org] Sent: Monday, November 10, 2014 3:30 AM To: Qu, Strong Cc: linaro-toolchain@lists.linaro.org Subject: Re: [Question] Should gdb client query FP registers even if gdb server does not report having org.gnu.gdb.aarch64.fpu feature? On 7 November 2014 02:27, Qu, Strong <stro...@qti.qualcomm.com> wrote: > Hello, > > > > We have implemented gdb server in one of our project and we are using > Linaro aarch64-none-elf-gdb.exe as gdb client. Our gdb server will > response to packet 'qXfer:features:read:target.xml:0,fff' with a xml > file which only claims feature ‘org.gnu.gdb.aarch64.core’. However, when I > issue ‘info reg’ > command with the gdb client, it actually sends out a packet ‘$p42#d6’, > which is trying to read fpsr if I understand correctly. Is this an > expected behavior or not? I just want to figure out whether our gdb > server send some bad info to the gdb client and made the client thinks > FP registers are valid. I hope I made my question clear and I’m really > appreciate if anybody can help us on this again. > > > > Thanks, > > > > Strong > > > _______________________________________________ > linaro-toolchain mailing list > linaro-toolchain@lists.linaro.org > http://lists.linaro.org/mailman/listinfo/linaro-toolchain > Hi Strong, GDB server will receive a register read request based on registers information given in xml target description on the client side. You can find these xml in gdb sources under: binutils-gdb/gdb/features If GDB is requesting a read for certain register that you expect it should not then you have to verify if its there in the xml description or not. There is a chance you might have developed your gdbserver implementation with some version that doesnt match with current version of linaro-gdb. I hope this helps. Let me know if you need to know anything further. Thanks! -- Omair _______________________________________________ linaro-toolchain mailing list linaro-toolchain@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-toolchain
