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Diffstat (limited to 'gdb/doc/gdb.texinfo')
| -rw-r--r-- | gdb/doc/gdb.texinfo | 31 |
1 files changed, 18 insertions, 13 deletions
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index a6bde12..6092ff4 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -8765,23 +8765,28 @@ are from the last memory unit printed; this is not the same as the last address printed if several units were printed on the last line of output. @cindex remote memory comparison +@cindex target memory comparison @cindex verify remote memory image +@cindex verify target memory image When you are debugging a program running on a remote target machine -(@pxref{Remote Debugging}), you may wish to verify the program's image in the -remote machine's memory against the executable file you downloaded to -the target. The @code{compare-sections} command is provided for such -situations. +(@pxref{Remote Debugging}), you may wish to verify the program's image +in the remote machine's memory against the executable file you +downloaded to the target. Or, on any target, you may want to check +whether the program has corrupted its own read-only sections. The +@code{compare-sections} command is provided for such situations. @table @code @kindex compare-sections @item compare-sections @r{[}@var{section-name}@r{|}@code{-r}@r{]} Compare the data of a loadable section @var{section-name} in the executable file of the program being debugged with the same section in -the remote machine's memory, and report any mismatches. With no +the target machine's memory, and report any mismatches. With no arguments, compares all loadable sections. With an argument of -@code{-r}, compares all loadable read-only sections. This command's -availability depends on the target's support for the @code{"qCRC"} -remote request. +@code{-r}, compares all loadable read-only sections. + +Note: for remote targets, this command can be accelerated if the +target supports computing the CRC checksum of a block of memory +(@pxref{qCRC packet}). @end table @node Auto Display @@ -17579,11 +17584,10 @@ the final result is inverted to ensure trailing zeros also affect the CRC. @emph{Note:} This is the same CRC polynomial as used in handling the -@dfn{Remote Serial Protocol} @code{qCRC} packet (@pxref{Remote Protocol, -, @value{GDBN} Remote Serial Protocol}). However in the -case of the Remote Serial Protocol, the CRC is computed @emph{most} -significant bit first, and the result is not inverted, so trailing -zeros have no effect on the CRC value. +@dfn{Remote Serial Protocol} @code{qCRC} packet (@pxref{qCRC packet}). +However in the case of the Remote Serial Protocol, the CRC is computed +@emph{most} significant bit first, and the result is not inverted, so +trailing zeros have no effect on the CRC value. To complete the description, we show below the code of the function which produces the CRC used in @code{.gnu_debuglink}. Inverting the @@ -34722,6 +34726,7 @@ Any other reply implies the old thread ID. @item qCRC:@var{addr},@var{length} @cindex CRC of memory block, remote request @cindex @samp{qCRC} packet +@anchor{qCRC packet} Compute the CRC checksum of a block of memory using CRC-32 defined in IEEE 802.3. The CRC is computed byte at a time, taking the most significant bit of each byte first. The initial pattern code |