In addition to reducing sim-specific code, it also avoids our local handle
allocation conflicting with the host GEM's handle numbering, which was
causing vc4_gem_hindex() to not distinguish between winsys BOs and the
same-numbered non-winsys bo.
This ensures that when I'm using the simulator, I get a closer match to
what behavior on real hardware will be. It lets me rapidly iterate on the
kernel validation code (which otherwise has a several-minute turnaround
time), and helps catch buffer overflow bugs in the userspace driver
faster.
This mostly just takes every draw call and turns it into a sequence of
commands that clear the FBO and draw a single shaded triangle to it,
regardless of the actual input vertices or shaders. I copied the initial
driver skeleton mostly from freedreno, and I've preserved Rob Clark's
copyright for those. I also based my initial hardcoded shaders and
command lists on Scott Mansell (phire)'s "hackdriver" project, though the
bit patterns of the shaders emitted end up being different.
v2: Rebase on gallium megadrivers changes.
v3: Rebase on PIPE_SHADER_CAP_MAX_CONSTS change.
v4: Rely on simpenrose actually being installed when building for
simulation.
v5: Add more header duplicate-include guards.
v6: Apply Emil's review (protection against vc4 sim and ilo at the same
time, and dropping the dricommon drm bits) and fix a copyright header
(thanks, Roland)
Eric Anholt