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GDB qXfer target description for real-mode qemu
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| <?xml version="1.0"?> | |
| <!-- Copyright (C) 2010-2017 Free Software Foundation, Inc. | |
| Copying and distribution of this file, with or without modification, | |
| are permitted in any medium without royalty provided the copyright | |
| notice and this notice are preserved. --> | |
| <!DOCTYPE target SYSTEM "gdb-target.dtd"> | |
| <target> | |
| <architecture>i8086</architecture> | |
| <feature name="org.gnu.gdb.i386.core"> | |
| <flags id="i386_eflags" size="4"> | |
| <field name="CF" start="0" end="0"/> | |
| <field name="" start="1" end="1"/> | |
| <field name="PF" start="2" end="2"/> | |
| <field name="AF" start="4" end="4"/> | |
| <field name="ZF" start="6" end="6"/> | |
| <field name="SF" start="7" end="7"/> | |
| <field name="TF" start="8" end="8"/> | |
| <field name="IF" start="9" end="9"/> | |
| <field name="DF" start="10" end="10"/> | |
| <field name="OF" start="11" end="11"/> | |
| <field name="NT" start="14" end="14"/> | |
| <field name="RF" start="16" end="16"/> | |
| <field name="VM" start="17" end="17"/> | |
| <field name="AC" start="18" end="18"/> | |
| <field name="VIF" start="19" end="19"/> | |
| <field name="VIP" start="20" end="20"/> | |
| <field name="ID" start="21" end="21"/> | |
| </flags> | |
| <reg name="eax" bitsize="32" type="int32"/> | |
| <reg name="ecx" bitsize="32" type="int32"/> | |
| <reg name="edx" bitsize="32" type="int32"/> | |
| <reg name="ebx" bitsize="32" type="int32"/> | |
| <reg name="esp" bitsize="32" type="data_ptr"/> | |
| <reg name="ebp" bitsize="32" type="data_ptr"/> | |
| <reg name="esi" bitsize="32" type="int32"/> | |
| <reg name="edi" bitsize="32" type="int32"/> | |
| <reg name="eip" bitsize="32" type="code_ptr"/> | |
| <reg name="eflags" bitsize="32" type="i386_eflags"/> | |
| <reg name="cs" bitsize="32" type="int32"/> | |
| <reg name="ss" bitsize="32" type="int32"/> | |
| <reg name="ds" bitsize="32" type="int32"/> | |
| <reg name="es" bitsize="32" type="int32"/> | |
| <reg name="fs" bitsize="32" type="int32"/> | |
| <reg name="gs" bitsize="32" type="int32"/> | |
| <reg name="st0" bitsize="80" type="i387_ext"/> | |
| <reg name="st1" bitsize="80" type="i387_ext"/> | |
| <reg name="st2" bitsize="80" type="i387_ext"/> | |
| <reg name="st3" bitsize="80" type="i387_ext"/> | |
| <reg name="st4" bitsize="80" type="i387_ext"/> | |
| <reg name="st5" bitsize="80" type="i387_ext"/> | |
| <reg name="st6" bitsize="80" type="i387_ext"/> | |
| <reg name="st7" bitsize="80" type="i387_ext"/> | |
| <reg name="fctrl" bitsize="32" type="int" group="float"/> | |
| <reg name="fstat" bitsize="32" type="int" group="float"/> | |
| <reg name="ftag" bitsize="32" type="int" group="float"/> | |
| <reg name="fiseg" bitsize="32" type="int" group="float"/> | |
| <reg name="fioff" bitsize="32" type="int" group="float"/> | |
| <reg name="foseg" bitsize="32" type="int" group="float"/> | |
| <reg name="fooff" bitsize="32" type="int" group="float"/> | |
| <reg name="fop" bitsize="32" type="int" group="float"/> | |
| </feature> | |
| <feature name="org.gnu.gdb.i386.32bit.sse"> | |
| <vector id="v4f" type="ieee_single" count="4"/> | |
| <vector id="v2d" type="ieee_double" count="2"/> | |
| <vector id="v16i8" type="int8" count="16"/> | |
| <vector id="v8i16" type="int16" count="8"/> | |
| <vector id="v4i32" type="int32" count="4"/> | |
| <vector id="v2i64" type="int64" count="2"/> | |
| <union id="vec128"> | |
| <field name="v4_float" type="v4f"/> | |
| <field name="v2_double" type="v2d"/> | |
| <field name="v16_int8" type="v16i8"/> | |
| <field name="v8_int16" type="v8i16"/> | |
| <field name="v4_int32" type="v4i32"/> | |
| <field name="v2_int64" type="v2i64"/> | |
| <field name="uint128" type="uint128"/> | |
| </union> | |
| <flags id="i386_mxcsr" size="4"> | |
| <field name="IE" start="0" end="0"/> | |
| <field name="DE" start="1" end="1"/> | |
| <field name="ZE" start="2" end="2"/> | |
| <field name="OE" start="3" end="3"/> | |
| <field name="UE" start="4" end="4"/> | |
| <field name="PE" start="5" end="5"/> | |
| <field name="DAZ" start="6" end="6"/> | |
| <field name="IM" start="7" end="7"/> | |
| <field name="DM" start="8" end="8"/> | |
| <field name="ZM" start="9" end="9"/> | |
| <field name="OM" start="10" end="10"/> | |
| <field name="UM" start="11" end="11"/> | |
| <field name="PM" start="12" end="12"/> | |
| <field name="FZ" start="15" end="15"/> | |
| </flags> | |
| <reg name="xmm0" bitsize="128" type="vec128" regnum="32"/> | |
| <reg name="xmm1" bitsize="128" type="vec128"/> | |
| <reg name="xmm2" bitsize="128" type="vec128"/> | |
| <reg name="xmm3" bitsize="128" type="vec128"/> | |
| <reg name="xmm4" bitsize="128" type="vec128"/> | |
| <reg name="xmm5" bitsize="128" type="vec128"/> | |
| <reg name="xmm6" bitsize="128" type="vec128"/> | |
| <reg name="xmm7" bitsize="128" type="vec128"/> | |
| <reg name="mxcsr" bitsize="32" type="i386_mxcsr" group="vector"/> | |
| </feature> | |
| </target> |
I can confirm that the issue faced by @schierlm occurs on Manjaro linux as well:
emote 'g' packet reply is too long (expected 308 bytes, got 344 bytes): 0000000000000000630600000000000000000000000000000000000000000000f0ff00000200000000f00000000000000000000000000000000000000000000000000000000000000000000010000060000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000007f030000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000801f0000
qemu:
QEMU emulator version 4.2.0
gdb:
GNU gdb (GDB) 9.1
me, too.
(gdb) set tdesc filename target.xml
warning: A handler for the OS ABI "GNU/Linux" is not built into this configuration
of GDB. Attempting to continue with the default i8086 settings.
Remote 'g' packet reply is too long: 000000000000000000000000000000000000000000000000e306050000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000f0ff0000000000000200000000f00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000010000060000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000007f0300000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000801f0000
qemu: QEMU emulator version 4.2.94
gdb: GNU gdb (Debian 7.12-6) 7.12.0.20161007-git
@meilihao That happens if the GDB you are debugging with differs to the GDB server you're connecting to. I have found setting the architecture your debugging GDB is using (with set architecture <arch>) fixes this issue
@rybot666, i cant not set arch.
(gdb) set arch i8086
warning: Selected architecture i8086 is not compatible with reported target architecture i386:x86-64
warning: A handler for the OS ABI "GNU/Linux" is not built into this configuration
of GDB. Attempting to continue with the default i8086 settings.
Architecture `i8086' not recognized.
The target architecture is set automatically (currently i386:x86-64)
@rybot666 This also does not seem to fix the issue for me:
(gdb) set architecture i8086
The target architecture is assumed to be i8086
(gdb) target remote :1234
Remote debugging using :1234
warning: No executable has been specified and target does not support
determining executable automatically. Try using the "file" command.
Remote 'g' packet reply is too long (expected 308 bytes, got 344 bytes): 0000000000000000630600000000000000000000000000000000000000000000f0ff00000200000000f00000000000000000000000000000000000000000000000000000000000000000000010000060000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000007f030000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000801f0000
It may be that the given target.xml is out of date and modern QEMU (I'm using 4.2.0) has changed how it reports data.
This works for me:
$ echo '<?xml version="1.0"?><!DOCTYPE target SYSTEM "gdb-target.dtd"><target><architecture>i8086</architecture><xi:include href="i386-32bit.xml"/></target>' > target.xml
$ wget https://raw.githubusercontent.com/qemu/qemu/master/gdb-xml/i386-32bit.xmland then:
(gdb) target remote localhost:26000
[...]
Breakpoint 1, 0x00007c00 in ?? ()
(gdb) x /5i 0x7c24
0x7c24: cli
0x7c25: cld
0x7c26: mov eax,0xc08e0050
0x7c2b: xor ebx,ebx
0x7c2d: mov al,0x2
(gdb) set tdesc filename target.xml
warning: A handler for the OS ABI "GNU/Linux" is not built into this configuration
of GDB. Attempting to continue with the default i8086 settings.
(gdb) x /5i 0x7c24
0x7c24: cli
0x7c25: cld
0x7c26: mov ax,0x50
0x7c29: mov es,ax
0x7c2b: xor bx,bx
Solution from @x746e works for me too
qemu:
QEMU emulator version 6.1.0
gdb:
GNU gdb (GDB) 10.2
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When trying to load this using
set tdesc filename ./target.xml, I get this:qemu 4.2.0 on Windows
and