[Question] Should gdb client query FP registers even if gdb server does not report having org.gnu.gdb.aarch64.fpu feature?
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 '$p42#d6', which is trying to read fpsr if I understand correctly. Is this an expected behavior or not? I just want to figure out whether our gdb server send some bad info to the gdb client and made the client thinks FP registers are valid. I hope I made my question clear and I'm really appreciate if anybody can help us on this again.
Thanks,
Strong
On 7 November 2014 02:27, Qu, Strong strongq@qti.qualcomm.com wrote:
Hello,
We have implemented gdb server in one of our project and we are using Linaro aarch64-none-elf-gdb.exe as gdb client. Our gdb server will response to packet 'qXfer:features:read:target.xml:0,fff' with a xml file which only claims feature ‘org.gnu.gdb.aarch64.core’. However, when I issue ‘info reg’ command with the gdb client, it actually sends out a packet ‘$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
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.javaid@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 strongq@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
Have you implemented a qXfer packet response if not you can do so to use xml description provided by target.
Here is a gdb help link that describe how to client can query target.xml.
https://sourceware.org/gdb/onlinedocs/gdb/Retrieving-Descriptions.html#Retri...
On 10 November 2014 19:42, Qu, Strong strongq@qti.qualcomm.com wrote:
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.javaid@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 strongq@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
Do we know if the Windows gdb binary links against expat? Without expat XML support is disabled.
On 11 November 2014 06:51, Omair Javaid omair.javaid@linaro.org wrote:
Have you implemented a qXfer packet response if not you can do so to use xml description provided by target.
Here is a gdb help link that describe how to client can query target.xml.
https://sourceware.org/gdb/onlinedocs/gdb/Retrieving-Descriptions.html#Retri...
On 10 November 2014 19:42, Qu, Strong strongq@qti.qualcomm.com wrote:
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.javaid@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 strongq@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
There was discussion to put with-expat in default config options not sure if that has been done or not.
On 11 November 2014 13:39, Will Newton will.newton@linaro.org wrote:
Do we know if the Windows gdb binary links against expat? Without expat XML support is disabled.
On 11 November 2014 06:51, Omair Javaid omair.javaid@linaro.org wrote:
Have you implemented a qXfer packet response if not you can do so to use xml description provided by target.
Here is a gdb help link that describe how to client can query target.xml.
https://sourceware.org/gdb/onlinedocs/gdb/Retrieving-Descriptions.html#Retri...
On 10 November 2014 19:42, Qu, Strong strongq@qti.qualcomm.com wrote:
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.javaid@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 strongq@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
-- Will Newton Toolchain Working Group, Linaro
Our code does response to qXfer packet. Here is dump from Linaro debugger:
Sending packet: $qXfer:features:read:target.xml:0,fff#7d...Packet received: l<?x ml version="1.0"?>\n<!DOCTYPE target SYSTEM "gdb-target.dtd">\n<target version=" 1.0">\n<feature name="org.gnu.gdb.aarch64.core">\n<reg name="x0" bitsize="64" re gnum="0" save-restore="no" type="uint64" group="general"/>\n<reg name="x1" bitsi ze="64" regnum="1" save-restore="no" type="uint64" group="general"/>\n<reg name= "x2" bitsize="64" regnum="2" save-restore="no" type="uint64" group="general"/>\n <reg name="x3" bitsize="64" regnum="3" save-restore="no" type="uint64" group="ge neral"/>\n<reg name="x4" bitsize="64" regnum="4" save-restore="no" type="uint64" group="general"/>\n<reg name="x5" bitsize="64" regnum="5" save-restore="no" typ e="uint64" group="general"/>\n<reg name="x6" bitsize="64" regnum="6" save-restor e="no" type="uint64" group="general"/>\n<reg name="x7" bitsize="64" regnum="7" s ave-restore="no" type="uint64" group="general"/>\n<reg name="x8" bitsize="64" re gnum="8" save-restore="no" type="uint64" group="general"/>\n<reg name="x9" bitsi ze="64" regnum="9" save-restore="no" type="uint64" group="general"/>\n<reg name= "x10" bitsize="64" regnum="10" save-restore="no" type="uint64" group="general"/> \n<reg name="x11" bitsize="64" regnum="11" save-restore="no" type="uint64" group ="general"/>\n<reg name="x12" bitsize="64" regnum="12" save-restore="no" type="u int64" group="general"/>\n<reg name="x13" bitsize="64" regnum="13" save-restore= "no" type="uint64" group="general"/>\n<reg name="x14" bitsize="64" regnum="14" s ave-restore="no" type="uint64" group="general"/>\n<reg name="x15" bitsize="64" r egnum="15" save-restore="no" type="uint64" group="general"/>\n<reg name="x16" bi tsize="64" regnum="16" save-restore="no" type="uint64" group="general"/>\n<reg n ame="x17" bitsize="64" regnum="17" save-restore="no" type="uint64" group="genera l"/>\n<reg name="x18" bitsize="64" regnum="18" save-restore="no" type="uint64" g roup="general"/>\n<reg name="x19" bitsize="64" regnum="19" save-restore="no" typ e="uint64" group="general"/>\n<reg name="x20" bitsize="64" regnum="20" save-rest ore="no" type="uint64" group="general"/>\n<reg name="x21" bitsize="64" regnum="2 1" save-restore="no" type="uint64" group="general"/>\n<reg name="x22" bitsize="6 4" regnum="22" save-restore="no" type="uint64" group="general"/>\n<reg name="x23 " bitsize="64" regnum="23" save-restore="no" type="uint64" group="general"/>\n<r eg name="x24" bitsize="64" regnum="24" save-restore="no" type="uint64" group="ge neral"/>\n<reg name="x25" bitsize="64" regnum="25" save-restore="no" type="uint6 4" group="general"/>\n<reg name="x26" bitsize="64" regnum="26" save-restore="no" type="uint64" group="general"/>\n<reg name="x27" bitsize="64" regnum="27" save- restore="no" type="uint64" group="general"/>\n<reg name="x28" bitsize="64" regnu m="28" save-restore="no" type="uint64" group="general"/>\n<reg name="x29" bitsiz e="64" regnum="29" save-restore="no" type="uint64" group="general"/>\n<reg name= "lr" bitsize="64" regnum="30" save-restore="no" type="code_ptr" group="general"/
\n<reg name="sp" bitsize="64" regnum="31" save-restore="no" type="data_ptr" gro
up="general"/>\n<reg name="pc" bitsize="64" regnum="32" save-restore="no" type=" code_ptr" group="general"/>\n<reg name="cpsr" bitsize="32" regnum="33" save-rest ore="no" type="uint32" group="general"/>\n</feature>\n</target>\n warning: Architecture rejected target-supplied description
I don't understand why Linaro gdb debugger print the last warning message. Anyway, currently I added code to return value of fpsr and fpcr and so far everything seems ok.
Thanks, Strong Qu
-----Original Message----- From: Omair Javaid [mailto:omair.javaid@linaro.org] Sent: Tuesday, November 11, 2014 5:43 AM To: Will Newton Cc: Qu, Strong; 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?
There was discussion to put with-expat in default config options not sure if that has been done or not.
On 11 November 2014 13:39, Will Newton will.newton@linaro.org wrote:
Do we know if the Windows gdb binary links against expat? Without expat XML support is disabled.
On 11 November 2014 06:51, Omair Javaid omair.javaid@linaro.org wrote:
Have you implemented a qXfer packet response if not you can do so to use xml description provided by target.
Here is a gdb help link that describe how to client can query target.xml.
https://sourceware.org/gdb/onlinedocs/gdb/Retrieving-Descriptions.htm l#Retrieving-Descriptions
On 10 November 2014 19:42, Qu, Strong strongq@qti.qualcomm.com wrote:
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.javaid@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 strongq@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
-- Will Newton Toolchain Working Group, Linaro
linaro-toolchain@lists.linaro.org
-
Omair Javaid -
Qu, Strong -
Will Newton