Commit Graph

9 Commits

Author SHA1 Message Date
Alex Bennée
ad66b5cbbb stubs: split semihosting_get_target from system only stubs
As we are about to have a common syscalls.c for gdbstub we need to
stub out one semihosting helper function for all targets.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230307170405.796822-1-alex.bennee@linaro.org>
2023-03-07 20:44:09 +00:00
Peter Maydell
5202861b20 semihosting: Allow optional use of semihosting from userspace
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>
2022-09-13 17:18:21 +01:00
Richard Henderson
fb08790b35 semihosting: Cleanup chardev init
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>
2022-06-28 04:35:52 +05:30
Thomas Huth
4c386f8064 Do not include sysemu/sysemu.h if it's not really necessary
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>
2021-05-02 17:24:50 +02:00
Philippe Mathieu-Daudé
6b5fe13786 semihosting: Move include/hw/semihosting/ -> include/semihosting/
We want to move the semihosting code out of hw/ in the next patch.

This patch contains the mechanical steps, created using:

  $ git mv include/hw/semihosting/ include/
  $ sed -i s,hw/semihosting,semihosting, $(git grep -l hw/semihosting)

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210226131356.3964782-2-f4bug@amsat.org>
Message-Id: <20210305135451.15427-2-alex.bennee@linaro.org>
2021-03-10 15:34:12 +00:00
Keith Packard
8de702cb67 semihosting: add qemu_semihosting_console_inc for SYS_READC
Provides a blocking call to read a character from the console using
semihosting.chardev, if specified. This takes some careful command
line options to use stdio successfully as the serial ports, monitor
and semihost all want to use stdio. Here's a sample set of command
line options which share stdio between semihost, monitor and serial
ports:

	qemu \
	-chardev stdio,mux=on,id=stdio0 \
	-serial chardev:stdio0 \
	-semihosting-config enable=on,chardev=stdio0 \
	-mon chardev=stdio0,mode=readline

This creates a chardev hooked to stdio and then connects all of the
subsystems to it. A shorter mechanism would be good to hear about.

Signed-off-by: Keith Packard <keithp@keithp.com>
Message-Id: <20191104204230.12249-1-keithp@keithp.com>
[AJB: fixed up deadlock, minor commit title reword]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Keith Packard <keithp@keithp.com>
Tested-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2020-01-09 11:41:29 +00:00
Markus Armbruster
d5938f29fe Clean up inclusion of sysemu/sysemu.h
In my "build everything" tree, changing sysemu/sysemu.h triggers a
recompile of some 5400 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).

Almost a third of its inclusions are actually superfluous.  Delete
them.  Downgrade two more to qapi/qapi-types-run-state.h, and move one
from char/serial.h to char/serial.c.

hw/semihosting/config.c, monitor/monitor.c, qdev-monitor.c, and
stubs/semihost.c define variables declared in sysemu/sysemu.h without
including it.  The compiler is cool with that, but include it anyway.

This doesn't reduce actual use much, as it's still included into
widely included headers.  The next commit will tackle that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-27-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2019-08-16 13:31:53 +02:00
Alex Bennée
4e7f9032cf semihosting: enable chardev backed output for console
It will be useful for a number of use-cases to be able to re-direct
output to a file like we do with serial output. This does the wiring
to allow us to treat then semihosting console like just another
character output device.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
2019-05-28 10:28:50 +01:00
Alex Bennée
16932bb761 semihosting: introduce CONFIG_SEMIHOSTING
There isn't much point building semihosting for platforms that don't
support it. Introduce a new symbol and enable it only for the softmmu
targets that need it.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2019-05-28 10:28:50 +01:00