-Writes a 32-bit @var{word} to register @var{num} (from 0 to 16)
-as used in the specified @var{mode}
-(where e.g. mode 16 is "user" and mode 19 is "supervisor";
-the M4..M0 bits of the PSR).
-Registers 0..15 are the normal CPU registers such as r0(0), r1(1) ... pc(15).
-Register 16 is the mode-specific SPSR,
-unless the specified mode is 0xffffffff (32-bit all-ones)
-in which case register 16 is the CPSR.
-The write goes directly to the CPU, bypassing the register cache.
-@end deffn
-
-@deffn {Debug Command} {arm7_9 write_xpsr} word (@option{0}|@option{1})
-@emph{This is intended for use while debugging OpenOCD; you probably
-shouldn't use it.}
-
-If the second parameter is zero, writes @var{word} to the
-Current Program Status register (CPSR).
-Else writes @var{word} to the current mode's Saved PSR (SPSR).
-In both cases, this bypasses the register cache.
-@end deffn
-
-@deffn {Debug Command} {arm7_9 write_xpsr_im8} byte rotate (@option{0}|@option{1})
-@emph{This is intended for use while debugging OpenOCD; you probably
-shouldn't use it.}
-
-Writes eight bits to the CPSR or SPSR,
-first rotating them by @math{2*rotate} bits,
-and bypassing the register cache.
-This has lower JTAG overhead than writing the entire CPSR or SPSR
-with @command{arm7_9 write_xpsr}.
+Semihosting allows for code executing on an ARM target to use the
+I/O facilities on the host computer i.e. the system where OpenOCD
+is running. The target application must be linked against a library
+implementing the ARM semihosting convention that forwards operation
+requests by using a special SVC instruction that is trapped at the
+Supervisor Call vector by OpenOCD.