semihosting tests: Add test of EXIT_EXTENDED

Add a minimal test of EXIT_EXTENDED if the implementation
provides it. Since using it at all exits the test, this is
not really possible to test properly in this single-binary
test setup, so we just use it for the final exit-success
if we can.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 41 insertions, 0 deletions

diff --git a/semihosting.c b/semihosting.c
index 9c284af..7a0ee0c 100644
--- a/semihosting.c
+++ b/semihosting.c
@@ -176,6 +176,21 @@ void semi_exit(int subcode)
     while(1); /* should not be reached */
 }
 
+void semi_exit_extended(int subcode)
+{
+    /* If present, this always allows a subcode to be reported. */
+    struct {
+        intptr_t reason;
+        intptr_t subcode;
+    } args;
+
+    args.reason = REPORTEXC_REASON_APP_EXIT;
+    args.subcode = subcode;
+    __semi_call(SYS_EXIT_EXTENDED, &args);
+
+    while(1); /* should not be reached */
+}
+
 void semi_fatal(char const *message)
 {
     semi_write0(message);
diff --git a/semihosting.h b/semihosting.h
index f8c4e7b..06cda8d 100644
--- a/semihosting.h
+++ b/semihosting.h
@@ -36,6 +36,7 @@
 #define SYS_GET_CMDLINE	0x15
 #define SYS_REPORTEXC	0x18
 #define REPORTEXC_REASON_APP_EXIT 0x20026
+#define SYS_EXIT_EXTENDED 0x20
 #define SEMIHOSTING_SVC	0x123456	/* SVC comment field for semihosting */
 
 #define FEATURE_DETECT_FILE ":semihosting-features"
@@ -43,6 +44,8 @@
 #define SHFB_MAGIC_1 0x48
 #define SHFB_MAGIC_2 0x46
 #define SHFB_MAGIC_3 0x42
+#define SH_EXT_EXIT_EXTENDED (1 << 0)
+#define SH_EXT_STDOUT_STDERR (1 << 1)
 
 #ifndef __ASSEMBLER__
 
@@ -61,6 +64,7 @@ int semi_get_cmdline(char *buffer, int size, int *length);
 int semi_reportexc(int reason, int subcode);
 void semi_fatal(char const *message);
 void semi_exit(int subcode);
+void semi_exit_extended(int subcode);
 /*
  * semi_load_file:
  * On entry *dest should be the buffer to write the data to, and
diff --git a/usertest.c b/usertest.c
index de915b7..ce0f61d 100644
--- a/usertest.c
+++ b/usertest.c
@@ -43,6 +43,9 @@ const char file[] = "Small file of text data for test.\n";
 #define TESTWRITE_FILE "tempdata.txt"
 const char writedata[] = "Data to write to temporary file.\n";
 
+int has_exit_extended;
+int has_stdout_stderr;
+
 static int test_istty(void)
 {
     int fd;
@@ -245,6 +248,20 @@ static int test_feature_detect(void)
 
     semi_write0("PASS semihosting features file read successfully\n");
 
+    /* Capture the feature flags we care about here for later tests */
+    if (filebuf[4] & SH_EXT_EXIT_EXTENDED) {
+        semi_write0("INFO implementation supports EXIT_EXTENDED\n");
+        has_exit_extended++;
+    }
+    if (filebuf[4] & SH_EXT_STDOUT_STDERR) {
+        semi_write0("INFO implementation supports STDOUT_STDERR\n");
+        has_stdout_stderr++;
+    }
+    if (filebuf[4] & ~(SH_EXT_EXIT_EXTENDED | SH_EXT_STDOUT_STDERR)) {
+        semi_write0("INFO implementation supports extensions "
+                    "this test doesn't know about\n");
+    }
+
     if (semi_istty(fd)) {
         semi_write0("FAIL semihosting features file is a TTY?\n");
     } else {
@@ -350,6 +367,11 @@ int main(void)
     }
 
     semi_write0("ALL TESTS PASSED\n");
+
+    /* If we have EXIT_EXTENDED then use it */
+    if (has_exit_extended) {
+        semi_exit_extended(0);
+    }
     semi_exit(0);
     /* not reached */
 }