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, 12 insertions, 0 deletions

diff --git a/usr/netd.c b/usr/netd.c
new file mode 100644
index 0000000..b07abd2
--- /dev/null
+++ b/usr/netd.c
@@ -0,0 +1,12 @@
+#include "sock.h"
+/* netd - the network daemon. It just pumps the kernel RX path; the kernel's
+   socket layer owns SLIP/IP and auto-answers inbound ICMP echo requests, so
+   running netd makes the Game Boy respond to pings. No SLIP/IP here anymore. */
+
+void main(void) {
+    puts("netd: up (10.0.0.2)"); nl();
+    for (;;) {
+        net_poll();     /* drain RX, answer pings */
+        yield();
+    }
+}