start experimenting with processor grids

1 files changed, 18 insertions, 0 deletions

diff --git a/tests/simple_uart/hello.c b/tests/simple_uart/hello.c
new file mode 100644
index 0000000..30719e0
--- /dev/null
+++ b/tests/simple_uart/hello.c
@@ -0,0 +1,18 @@
+/* compile with
+ *	riscv64-unknown-elf-gcc -ffreestanding -nostdlib -Wl,-Ttext=0 -march=rv64i -mabi=lp64 -O2 hello.c -o simple_hello
+ *	xxd --include simple_hello
+ */
+void _start()
+{
+	/* relies on hard-coded system, good enough for this simple test */
+	volatile char *uart = (char *)4096;
+	*uart = 'H';
+	*uart = 'e';
+	*uart = 'l';
+	*uart = 'l';
+	*uart = 'o';
+	*uart = '!';
+	*uart = '\n';
+
+	asm ("ebreak\n");
+}