Add QEMU upstream remote and checkout stable branch

Author: Gulshan Singh

Makefile

@@ -400,6 +400,8 @@ TRUSTY_TARGET ?= qemu-generic-arm64-test-debug
 TRUSTY_BUILD_ROOT ?= $(OUT_DIR)/trusty
 TRUSTY_OUT := $(TRUSTY_BUILD_ROOT)/build-$(TRUSTY_TARGET)
 
+QEMU_BRANCH := stable-7.2
+
 ATF_DIR := $(TRUSTY_OUT)/atf/qemu/debug
 ATF_BL1 := $(ATF_DIR)/bl1.bin
 ATF_BL33 := $(ATF_DIR)/bl33.bin
@@ -421,14 +423,19 @@ trusty-init: | $(TRUSTY_SRC)
 	$(MAKE) trusty-qemu-init
 
 # QEMU 3.0 is used by trusty by default. Let's use something newer, we just
-# need to apply some Android-specific patches
+# need to apply some Android-specific patches:
+#   a4d024b2 arm_gic: Implement GICC_AIAR, GICC_AEOIR and GICC_AHPPIR
+#   f0600685 Fix GIC model for aliased interrupts
+#   8a933fbb hw/virt/arm: double the amount of secure memory
+#   0bfea659 hw/arm/virt: Commandeer most of PCIE_MMIO region for secure memory
 .PHONY: trusty-qemu-init
 trusty-qemu-init:
-	# TODO: Make this a loop, put commit message of each in a comment
-	# TODO: Hardcode a stable version commit instead
-	# TODO: Can we skip the third one
+	- cd $(TRUSTY_SRC)/external/qemu \
+		&& git remote add upstream https://gitlab.com/qemu-project/qemu.git
+
 	cd $(TRUSTY_SRC)/external/qemu \
-		&& git checkout aosp/upstream-master \
+		&& git fetch upstream $(QEMU_BRANCH) \
+		&& git checkout upstream/$(QEMU_BRANCH) \
 		&& git cherry-pick a4d024b2fdcc478402d00890965eeacb5542c12e \
 		&& git cherry-pick f060068503259b661be8bd8c803291ff6412d2d6 \
 		&& git cherry-pick 8a933fbb9c6fb8add1c74f5b523ecb44da7372fa \