refactor: c/ -> usr/, compiled program blobs out of the source tree

Userland sources live in usr/ (fits the Unix theme better than 'c').
SDCC output .bin blobs land in build/usr/ with the other build artifacts
instead of littering the source dir; programs.asm INCBINs them from there.
Byte-identical ROM.

1 files changed, 13 insertions, 0 deletions

diff --git a/usr/necho.c b/usr/necho.c
new file mode 100644
index 0000000..99551d4
--- /dev/null
+++ b/usr/necho.c
@@ -0,0 +1,13 @@
+#include "netlib.h"
+/* necho: send a SLIP-framed packet over the link port and print the reply.
+   Talks to a host gateway (tools/gateway.py) that echoes frames back. */
+
+void main(void) {
+    char buf[64];
+    unsigned char len;
+    puts("net: send 'hello from gbos'"); nl();
+    slip_send("hello from gbos", 15);
+    len = slip_recv(buf, 63);
+    buf[len] = 0;
+    puts("net: recv '"); puts(buf); puts("'"); nl();
+}