docs: Roll semihosting option information into qemu-options.hx

Currently the per-target documentation for those targets that
implement semihosting includes a bit of text that goes into both the
manual and the manpage about options specific to the target.  This
text is redundant with the earlier generic option description of the
semihosting option produced from qemu-options.hx. To avoid having
to create a lot of stub include files to include into the rST
generated qemu.1 manpage, roll target-specific bits of information
into the qemu-options.hx text, so the user doesn't have to look
in two places for this information.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20200228153619.9906-24-peter.maydell@linaro.org

docs/system/target-arm.rst

@@ -215,13 +215,3 @@ emulation includes the following elements:
 
 A Linux 2.6 test image is available on the QEMU web site. More
 information is available in the QEMU mailing-list archive.
-
-The following options are specific to the ARM emulation:
-
-``-semihosting``
-   Enable semihosting syscall emulation.
-
-   On ARM this implements the \"Angel\" interface.
-
-   Note that this allows guest direct access to the host filesystem, so
-   should only be used with trusted guest OS.

docs/system/target-arm.texi

@@ -243,21 +243,3 @@ Three on-chip UARTs
 A Linux 2.6 test image is available on the QEMU web site. More
 information is available in the QEMU mailing-list archive.
 
-@c man begin OPTIONS
-
-The following options are specific to the ARM emulation:
-
-@table @option
-
-@item -semihosting
-Enable semihosting syscall emulation.
-
-On ARM this implements the "Angel" interface.
-
-Note that this allows guest direct access to the host filesystem,
-so should only be used with trusted guest OS.
-
-@end table
-
-@c man end
-

docs/system/target-m68k.rst

@@ -19,14 +19,3 @@ The AN5206 emulation includes the following devices:
 -  MCF5206 ColdFire V2 Microprocessor.
 
 -  Two on-chip UARTs.
-
-The following options are specific to the ColdFire emulation:
-
-``-semihosting``
-   Enable semihosting syscall emulation.
-
-   On M68K this implements the \"ColdFire GDB\" interface used by
-   libgloss.
-
-   Note that this allows guest direct access to the host filesystem, so
-   should only be used with trusted guest OS.

docs/system/target-m68k.texi

@@ -23,22 +23,3 @@ MCF5206 ColdFire V2 Microprocessor.
 @item
 Two on-chip UARTs.
 @end itemize
-
-@c man begin OPTIONS
-
-The following options are specific to the ColdFire emulation:
-
-@table @option
-
-@item -semihosting
-Enable semihosting syscall emulation.
-
-On M68K this implements the "ColdFire GDB" interface used by libgloss.
-
-Note that this allows guest direct access to the host filesystem,
-so should only be used with trusted guest OS.
-
-@end table
-
-@c man end
-

docs/system/target-xtensa.rst

@@ -25,15 +25,3 @@ The Avnet LX60/LX110/LX200 emulation supports:
 -  16550 UART
 
 -  OpenCores 10/100 Mbps Ethernet MAC
-
-The following options are specific to the Xtensa emulation:
-
-``-semihosting``
-   Enable semihosting syscall emulation.
-
-   Xtensa semihosting provides basic file IO calls, such as
-   open/read/write/seek/select. Tensilica baremetal libc for ISS and
-   linux platform \"sim\" use this interface.
-
-   Note that this allows guest direct access to the host filesystem, so
-   should only be used with trusted guest OS.

docs/system/target-xtensa.texi

@@ -33,23 +33,3 @@ A range of Xtensa CPUs, default is the DC232B
 @item
 OpenCores 10/100 Mbps Ethernet MAC
 @end itemize
-
-@c man begin OPTIONS
-
-The following options are specific to the Xtensa emulation:
-
-@table @option
-
-@item -semihosting
-Enable semihosting syscall emulation.
-
-Xtensa semihosting provides basic file IO calls, such as open/read/write/seek/select.
-Tensilica baremetal libc for ISS and linux platform "sim" use this interface.
-
-Note that this allows guest direct access to the host filesystem,
-so should only be used with trusted guest OS.
-
-@end table
-
-@c man end
-

qemu-options.hx

@@ -4116,6 +4116,12 @@ STEXI
 @item -semihosting
 @findex -semihosting
 Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only).
+
+Note that this allows guest direct access to the host filesystem, so
+should only be used with a trusted guest OS.
+
+See the -semihosting-config option documentation for further information
+about the facilities this enables.
 ETEXI
 DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
     "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \
@@ -4126,6 +4132,18 @@ STEXI
 @item -semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]
 @findex -semihosting-config
 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II only).
+
+Note that this allows guest direct access to the host filesystem, so
+should only be used with a trusted guest OS.
+
+On Arm this implements the standard semihosting API, version 2.0.
+
+On M68K this implements the "ColdFire GDB" interface used by libgloss.
+
+Xtensa semihosting provides basic file IO calls, such as
+open/read/write/seek/select. Tensilica baremetal libc for ISS and
+linux platform "sim" use this interface.
+
 @table @option
 @item target=@code{native|gdb|auto}
 Defines where the semihosting calls will be addressed, to QEMU (@code{native})