[kvm-unit-tests RFC PATCH 1/5] lib: arm: Print test exit status on exit if chr-testdev is not availa

The arm64 tests can be run under kvmtool, which doesn't emulate a
chr-testdev device. In preparation for adding run script support for
kvmtool, print the test exit status so the scripts can pick it up and
correctly mark the test as pass or fail.

Signed-off-by: Alexandru Elisei <[email protected]>
---
 lib/chr-testdev.h |  1 +
 lib/arm/io.c      | 10 +++++++++-
 lib/chr-testdev.c |  5 +++++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/chr-testdev.h b/lib/chr-testdev.h
index ffd9a851aa9b..09b4b424670e 100644
--- a/lib/chr-testdev.h
+++ b/lib/chr-testdev.h
@@ -11,4 +11,5 @@
  */
 extern void chr_testdev_init(void);
 extern void chr_testdev_exit(int code);
+extern bool chr_testdev_available(void);
 #endif
diff --git a/lib/arm/io.c b/lib/arm/io.c
index 343e10822263..9e62b571a91b 100644
--- a/lib/arm/io.c
+++ b/lib/arm/io.c
@@ -125,7 +125,15 @@ extern void halt(int code);
 
 void exit(int code)
 {
-	chr_testdev_exit(code);
+	if (chr_testdev_available()) {
+		chr_testdev_exit(code);
+	} else {
+		/*
+		 * Print the test return code in the format used by chr-testdev
+		 * so the runner script can parse it.
+		 */
+		printf("\nEXIT: STATUS=%d\n", ((code) << 1) | 1);
+	}
 	psci_system_off();
 	halt(code);
 	__builtin_unreachable();
diff --git a/lib/chr-testdev.c b/lib/chr-testdev.c
index b3c641a833fe..301e73a6c064 100644
--- a/lib/chr-testdev.c
+++ b/lib/chr-testdev.c
@@ -68,3 +68,8 @@ void chr_testdev_init(void)
 	in_vq = vqs[0];
 	out_vq = vqs[1];
 }
+
+bool chr_testdev_available(void)
+{
+	return vcon != NULL;
+}
-- 
2.32.0