OvmfPkg: QemuVideoDxe: work around misreported QXL framebuffer size

When setting up the list of GOP modes offered on QEMU's stdvga ("VGA") and
QXL ("qxl-vga") video devices, QemuVideoBochsModeSetup() filters those
modes against the available framebuffer size. (Refer to SVN r15288 / git
commit ec88061e.)

The VBE_DISPI_INDEX_VIDEO_MEMORY_64K register of both stdvga and QXL is
supposed to report the size of the drawable, VGA-compatibility
framebuffer. Instead, up to and including qemu-2.1, this register actually
reports the full video RAM (PCI BAR 0) size.

In case of stdvga, this happens to be correct, because on that card the
full PCI BAR 0 is usable for drawing; there is no difference between
"drawable framebuffer size" and "video RAM (PCI BAR 0) size".

However, on the QXL card, only an initial portion of the video RAM is
suitable for drawing, as compatibility framebuffer; and the value
currently reported by VBE_DISPI_INDEX_VIDEO_MEMORY_64K overshoots the
valid size. Beyond the drawable range, the video RAM contains buffers and
structures for the QXL guest-host protocol.

Luckily, the size of the drawable QXL framebuffer can also be read from a
register in the QXL ROM BAR (PCI BAR 2), so let's retrieve it from there.

Without this fix, OVMF offers too large resolutions on the QXL card (up to
the full size of the video RAM). If a GOP client selects such a resolution
and draws into the video RAM past the compatibility segment, then the
guest corrupts its communication structures (which is invalid guest
behavior).

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15978 6f19259b-4bc3-4df7-8a09-765794883524
BaseTools: Add the XCODE5 tools target to supoprt Xcode 5

Xcode 5 changed the arguments required to supoprt X64 EFIAPI so it is a new 
target. XCODE5 supports Xcode 5.* and Xcode 6.*, and will probably support
future versions of Xcode as well. 

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Anderw Fish <afish@apple.com>
Reviewed-by: Gao, Liming <liming.gao@intel.com> 



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15979 6f19259b-4bc3-4df7-8a09-765794883524
BaseTools: Cleanup XCODE build rules

Update C-Code-File rule since XCODE never needs the SYMRENAME step.
Add *.S16 to Mash16-Code-File rule to supoprt 16-bit assmebly with XCODE

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Anderw Fish <afish@apple.com>
Reviewed-by: Gao, Liming <liming.gao@intel.com> 


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15980 6f19259b-4bc3-4df7-8a09-765794883524
EmulatorPkg: Unix: Fix uninitiailzed variable bug.

clang warns on this error.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Anderw Fish <afish@apple.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15981 6f19259b-4bc3-4df7-8a09-765794883524
EmulatorPkg: Unix: Add LLDB support for Xcode 5

Xcode5 retired gdb, so this patch adds support for using, and loading symbols
in, lldb. It also supports building with Xcode 5.

The lldb script also supports dumping out the build generated guid database
and it prints guids out with thier Cname if available. lldbefi.py also
contains some EFI specific type formatters. Symbols are loaded via the
lldbefi.py script setting a breakpoint on SecGdbScriptBreak() and runing a
breakpoint action Python function that uses the arguments to
SecGdbScriptBreak() to load symbols.

The location of SecGdbScriptBreak() in Host.c was updated to move symbol
loading control into the lldb Python script, since lldb only uses the
arguments to SecGdbScriptBreak() and not the files generated by the
emulator. The +1 on the SecGdbScriptBreak() argument makes it string size,
not string length, as this is what the lldb script is looking for.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Anderw Fish <afish@apple.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15982 6f19259b-4bc3-4df7-8a09-765794883524
EmulatorPkg: Unix: Use XCODE5 and lldb if Xcode 5 is detected

The EmulatorPkg build.sh will use XCODE5 if that is the default toolchain, and
default to using lldb if Xcode 5 is dectect. This will work for Xcode 6 and 
possibly future version of Xcode too.

/usr/bin/clang is just a wrapper that calls the currently selected Xcode 
version. xcode-select is used used to display or set the current version of
Xcode used by the command line tools. 

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Anderw Fish <afish@apple.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15983 6f19259b-4bc3-4df7-8a09-765794883524