[v3][PATCH] tools/hvmloader: link errno.h from xen internal

[Tiejun Chen <tiejun.chen@intel.com>]

We need to act on some specific hypercall error numbers, so
require the hypervisor view on the errno.h value rather than
just the build environment's number. So here link this headfile
from xen.

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
---
v3:

* Address Jan's two comments
  The file name would seem quite right to be used as dependency here.
  subdirs-all should depend on errno.h

v2:

* CCed more tools MAINTAINERS
* Rephrase long log
* Remove this line '@rm -rf errno.h' since we always force link
* Drop including this head file in util.h directly

 .gitignore                        | 1 +
 tools/firmware/hvmloader/Makefile | 7 ++++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index b24e905..52c3038 100644
--- a/.gitignore
+++ b/.gitignore
@@ -127,6 +127,7 @@ tools/firmware/hvmloader/acpi/ssdt_*.h
 tools/firmware/hvmloader/hvmloader
 tools/firmware/hvmloader/roms.h
 tools/firmware/hvmloader/roms.inc
+tools/firmware/hvmloader/errno.h
 tools/firmware/rombios/BIOS-bochs-[^/]*
 tools/firmware/rombios/_rombios[^/]*_.c
 tools/firmware/rombios/rombios[^/]*.s
diff --git a/tools/firmware/hvmloader/Makefile b/tools/firmware/hvmloader/Makefile
index 46a79c5..ef2337b 100644
--- a/tools/firmware/hvmloader/Makefile
+++ b/tools/firmware/hvmloader/Makefile
@@ -87,6 +87,11 @@ endif
 all: subdirs-all
 	$(MAKE) hvmloader
 
+subdirs-all: errno.h
+
+errno.h:
+	ln -sf $(XEN_ROOT)/xen/include/xen/errno.h .
+
 ovmf.o rombios.o seabios.o hvmloader.o: roms.inc
 smbios.o: CFLAGS += -D__SMBIOS_DATE__="\"$(shell date +%m/%d/%Y)\""
 
@@ -136,7 +141,7 @@ endif
 
 .PHONY: clean
 clean: subdirs-clean
-	rm -f roms.inc roms.inc.new acpi.h
+	rm -f roms.inc roms.inc.new acpi.h errno.h
 	rm -f hvmloader hvmloader.tmp *.o $(DEPS)
 
 -include $(DEPS)
-- 
1.9.1