Currently our semihosting implementations generally prohibit use of
semihosting calls in system emulation from the guest userspace. This
is a very long standing behaviour justified originally "to provide
some semblance of security" (since code with access to the
semihosting ABI can do things like read and write arbitrary files on
the host system). However, it is sometimes useful to be able to run
trusted guest code which performs semihosting calls from guest
userspace, notably for test code. Add a command line suboption to
the existing semihosting-config option group so that you can
explicitly opt in to semihosting from guest userspace with
-semihosting-config userspace=on
(There is no equivalent option for the user-mode emulator, because
there by definition all code runs in userspace and has access to
semihosting already.)
This commit adds the infrastructure for the command line option and
adds a bool 'is_user' parameter to the function
semihosting_userspace_enabled() that target code can use to check
whether it should be permitting the semihosting call for userspace.
It mechanically makes all the callsites pass 'false', so they
continue checking "is semihosting enabled in general". Subsequent
commits will make each target that implements semihosting honour the
userspace=on option by passing the correct value and removing
whatever "don't do this for userspace" checking they were doing by
hand.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220822141230.3658237-2-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Rename qemu_semihosting_connect_chardevs to
qemu_semihosting_chardev_init; pass the result
directly to qemu_semihosting_console_init.
Store the chardev in SemihostingConsole instead
of SemihostingConfig, which lets us drop
semihosting_get_chardev.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Currently we mishandle the --semihosting-config option if the
user specifies it on the command line more than once. For
example with:
--semihosting-config target=gdb --semihosting-config arg=foo,arg=bar
the function qemu_semihosting_config_options() is called twice, once
for each argument. But that function expects to be called only once,
and it always unconditionally sets the semihosting.enabled,
semihost_chardev and semihosting.target variables. This means that
if any of those options were set anywhere except the last
--semihosting-config option on the command line, those settings are
ignored. In the example above, 'target=gdb' in the first option is
overridden by an implied default 'target=auto' in the second.
The QemuOptsList machinery has a flag for handling this kind of
"option group is setting global state": by setting
.merge_lists = true;
we make the machinery merge all the --semihosting-config arguments
the user passes into a single set of options and call our
qemu_semihosting_config_options() just once.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Luc Michel <luc@lmichel.fr>
Message-id: 20220526190053.521505-3-peter.maydell@linaro.org
Another cleanup patch tripped over the fact we weren't being careful
in our casting. Fix the casts, allow for a non-const and switch from
g_realloc to g_renew.
The whole semihosting argument handling could do with some tests
though.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220315121251.2280317-8-alex.bennee@linaro.org>
Stop including sysemu/sysemu.h in files that don't need it.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-2-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
With the exception of hw/core/, the hw/ directory only contains
device models used in system emulation. Semihosting is also used
by user emulation. As a generic feature, move it out of hw/ directory.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210226131356.3964782-3-f4bug@amsat.org>
Message-Id: <20210305135451.15427-3-alex.bennee@linaro.org>
