Introduce an RSP packet, 'x', for reading from the remote server memory in binary format. The binary write packet, 'X' already exists. The 'x' packet is essentially the same as 'm', except that the returned data is in binary format. For transferring relatively large data from the memory of the remote process, the 'x' packet can reduce the transfer costs. For example, without this patch, fetching ~100MB of data from a remote target takes (gdb) dump binary memory temp.o 0x00007f3ba4c576c0 0x00007f3bab709400 2024-03-13 16:17:42.626 - command started 2024-03-13 16:18:24.151 - command finished Command execution time: 32.136785 (cpu), 41.525515 (wall) (gdb) whereas with this patch, we obtain (gdb) dump binary memory temp.o 0x00007fec39fce6c0 0x00007fec40a80400 2024-03-13 16:20:48.609 - command started 2024-03-13 16:21:16.873 - command finished Command execution time: 20.447970 (cpu), 28.264202 (wall) (gdb) We see improvements not only when reading bulk data as above, but also when making a large number of small memory access requests. For example, without this patch: (gdb) pipe x/100000xw $pc | wc -l 2024-03-13 16:04:57.112 - command started 25000 2024-03-13 16:05:10.798 - command finished Command execution time: 9.952364 (cpu), 13.686581 (wall) With this patch: (gdb) pipe x/100000xw $pc | wc -l 2024-03-13 16:06:48.160 - command started 25000 2024-03-13 16:06:57.750 - command finished Command execution time: 6.541425 (cpu), 9.589839 (wall) (gdb) Another example, where we create a core file of a GDB process. (gdb) gcore /tmp/core.1 ... Command execution time: 85.496967 (cpu), 133.224373 (wall) vs. (gdb) gcore /tmp/core.1 ... Command execution time: 48.328885 (cpu), 115.032289 (wall) Regression-tested on X86-64 using the unix (default) and native-extended-gdbserver board files. Reviewed-By: Eli Zaretskii <eliz@gnu.org> Approved-By: Tom Tromey <tom@tromey.com>