3 files changed, 124 insertions, 0 deletions
diff --git a/tools/testing/selftests/size/.gitignore b/tools/testing/selftests/size/.gitignore
new file mode 100644
index 000000000..923e18eed
--- /dev/null
+++ b/tools/testing/selftests/size/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+get_size
diff --git a/tools/testing/selftests/size/Makefile b/tools/testing/selftests/size/Makefile
new file mode 100644
index 000000000..b87facc00
--- /dev/null
+++ b/tools/testing/selftests/size/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+CFLAGS := -static -ffreestanding -nostartfiles -s
+
+TEST_GEN_PROGS := get_size
+
+include ../lib.mk
diff --git a/tools/testing/selftests/size/get_size.c b/tools/testing/selftests/size/get_size.c
new file mode 100644
index 000000000..2980b1a63
--- /dev/null
+++ b/tools/testing/selftests/size/get_size.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2014 Sony Mobile Communications Inc.
+ *
+ * Selftest for runtime system size
+ *
+ * Prints the amount of RAM that the currently running system is using.
+ *
+ * This program tries to be as small as possible itself, to
+ * avoid perturbing the system memory utilization with its
+ * own execution.  It also attempts to have as few dependencies
+ * on kernel features as possible.
+ *
+ * It should be statically linked, with startup libs avoided.  It uses
+ * no library calls except the syscall() function for the following 3
+ * syscalls:
+ *   sysinfo(), write(), and _exit()
+ *
+ * For output, it avoids printf (which in some C libraries
+ * has large external dependencies) by  implementing it's own
+ * number output and print routines, and using __builtin_strlen()
+ *
+ * The test may crash if any of the above syscalls fails because in some
+ * libc implementations (e.g. the GNU C Library) errno is saved in
+ * thread-local storage, which does not get initialized due to avoiding
+ * startup libs.
+ */
+
+#include <sys/sysinfo.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+
+#define STDOUT_FILENO 1
+
+static int print(const char *s)
+{
+	size_t len = 0;
+
+	while (s[len] != '\0')
+		len++;
+
+	return syscall(SYS_write, STDOUT_FILENO, s, len);
+}
+
+static inline char *num_to_str(unsigned long num, char *buf, int len)
+{
+	unsigned int digit;
+
+	/* put digits in buffer from back to front */
+	buf += len - 1;
+	*buf = 0;
+	do {
+		digit = num % 10;
+		*(--buf) = digit + '0';
+		num /= 10;
+	} while (num > 0);
+
+	return buf;
+}
+
+static int print_num(unsigned long num)
+{
+	char num_buf[30];
+
+	return print(num_to_str(num, num_buf, sizeof(num_buf)));
+}
+
+static int print_k_value(const char *s, unsigned long num, unsigned long units)
+{
+	unsigned long long temp;
+	int ccode;
+
+	print(s);
+
+	temp = num;
+	temp = (temp * units)/1024;
+	num = temp;
+	ccode = print_num(num);
+	print("\n");
+	return ccode;
+}
+
+/* this program has no main(), as startup libraries are not used */
+void _start(void)
+{
+	int ccode;
+	struct sysinfo info;
+	unsigned long used;
+	static const char *test_name = " get runtime memory use\n";
+
+	print("TAP version 13\n");
+	print("# Testing system size.\n");
+
+	ccode = syscall(SYS_sysinfo, &info);
+	if (ccode < 0) {
+		print("not ok 1");
+		print(test_name);
+		print(" ---\n reason: \"could not get sysinfo\"\n ...\n");
+		syscall(SYS_exit, ccode);
+	}
+	print("ok 1");
+	print(test_name);
+
+	/* ignore cache complexities for now */
+	used = info.totalram - info.freeram - info.bufferram;
+	print("# System runtime memory report (units in Kilobytes):\n");
+	print(" ---\n");
+	print_k_value(" Total:  ", info.totalram, info.mem_unit);
+	print_k_value(" Free:   ", info.freeram, info.mem_unit);
+	print_k_value(" Buffer: ", info.bufferram, info.mem_unit);
+	print_k_value(" In use: ", used, info.mem_unit);
+	print(" ...\n");
+	print("1..1\n");
+
+	syscall(SYS_exit, 0);
+}