The read/write implementations call directly into the console drivers
using the hook mechanism, causing faults if invoked from user mode.
Add system calls for read() and write() such that we do a privilege
elevation first.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The stdout console implementations for minimal libc call directly into
the various console drivers (depending on what specifc hooks are
registered) causing faults when invoked from user mode. This happens,
for example, when using printf() which eventually ends up calling
fputc().
The proper solution is to ensure privileges have been elevated before
the _stdout_hook is called. This was already done for printk().
puts() and fputs() have now been re-defined in terms of the
fputc() and fwrite() functions, which are now system calls.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
