If using the libc for Noux programs, the default implementation of these
functions cannot be used because they rely on a dedicated
timeout-scheduler thread. Noux programs, however, are expected to
contain only the main thread. By turning the functions into weak
symbols, the noux libc-plugin can provide custom implementations.
This patch introduces the basic key handling required to browse through
a multi-page PDF document ([page-up] or [enter] -> next page,
[page-down] or [backspace] -> previous page).
This way, we can register a meaningful 'user_data' pointer to at the
'pdfapp_t' structure and avoid the use of singletons for 'Framebuffer'
and 'pdfapp'.
This version of MuPDF will use Genode's framebuffer session and input
session to display a PDF file. At the current stage, the program is
merely a skeleton that compiles and starts. Neither the actual rendering
not the response to user input are implemented. To try it out, there
is a ready-to-use run script at 'libports/run/mupdf.run'.
As a preliminary step for working on issue #11, this patch revisits the
'Framebuffer::info' RPC call. Instead of using C-style out paramters,
the new 'mode()' RPC call returns the mode information as an object of
type 'Mode'. Consequently, mode-specific functions such as
'bytes_per_pixel' have been moved to the new 'Framebuffer::Mode' class.
At the startup of python's termios module, a sequence of 'tcgetattr' and
'tcsetattr' calls is executed. If one of those calls fails, the
initialization gets canceled. 'tcgetattr' is implemented via ioctl
operations on stdout. To let those operations succeed, the default
implementation of ioctl ('Plugin::ioctl') cannot be used because it
returns -1. Adding a dummy ioctl to the libc_log back end alleviates
this problem.
MuPDF is a fast and versatile PDF rendering library with only a few
dependencies. It depends on openjpeg (JPEG2000 codec) and jbig2dec (b/w
image compression library). Therefore, this patch comprises the ports of
these libraries as well. All libraries compile well in the Genode build
system but are not tested yet.
Removed dummy implementation of '_ioctl'. This function is called
internally within the libc, i.e., by 'tcgetattr'. For running
libreadline in Noux, we need to hook into those ioctl operations via
the libc plugin interface.
Norman Feske
Julian Stecklina
Genode Labs