Peter Maydell <peter.mayd...@linaro.org> writes:
> 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.mayd...@linaro.org> Acked-by: Alex Bennée <alex.ben...@linaro.org> -- Alex Bennée
