add 1d mesh node and refactor 2d mesh node

+ Seems to decrease performance a little bit, presumably due to
  extra register copy, but simplifies code a lot and opens up more
  genericism so I'll consider it an upgrade for now. Copying packets
  around is rather slow though, might in the future move to some
  kind of pointer based packet handling

1 files changed, 55 insertions, 0 deletions

diff --git a/tests/simple_mesh2d/test.c b/tests/simple_mesh2d/test.c
new file mode 100644
index 0000000..d607a59
--- /dev/null
+++ b/tests/simple_mesh2d/test.c
@@ -0,0 +1,55 @@
+__attribute__((always_inline))
+static inline void print_int8(volatile char *uart, unsigned x)
+{
+	*uart = ((x >> 4) & 0xf) + '0';
+	*uart = ((x >> 0) & 0xf) + '0';
+}
+
+__attribute__((always_inline))
+static inline void print_addr(volatile char *uart, unsigned x, unsigned y)
+{
+	*uart = '(';
+	print_int8(uart, x);
+	*uart = ',';
+	*uart = ' ';
+	print_int8(uart, y);
+	*uart = ')';
+	*uart = '\n';
+}
+
+__attribute__((always_inline))
+static inline unsigned wrap(unsigned x, unsigned X)
+{
+	return x + 1 >= X ? 0 : x + 1;
+}
+
+__attribute__((always_inline))
+static inline unsigned next_idx(unsigned x, unsigned y, unsigned X, unsigned Y)
+{
+	unsigned yi = wrap(y, Y);
+	unsigned xi = yi < y ? wrap(x, X) : x;
+
+	return (xi << 16) | yi;
+}
+
+void _start(unsigned x, unsigned y, unsigned X, unsigned Y)
+{
+	volatile char *uart = (char *)4096;
+	volatile unsigned *control = (unsigned *)(1ULL << 56);
+
+	if (x == 0 && y == 2) {
+		goto do_work;
+	} else {
+		while (*control != ((x << 16) | y)) {}
+	}
+
+do_work:
+	print_addr(uart, x, y);
+	*control = next_idx(x, y, X, Y);
+
+	if (x == X - 1 && y == Y - 1)
+		asm("ebreak");
+
+	/* otherwise just loop */
+	while (1) {}
+}