usr: ntpdate + date - the Game Boy knows what day it isHEADmaster

An MBC5 cart has no RTC, so SNTP is the only route to a wall clock. ntpdate
does one 48-byte UDP exchange on port 123 and hands the stamp to the kernel;
SYS_SETTIME keeps it with the tick it arrived at, and SYS_GETTIME adds the
elapsed ticks back, so date(1) is just formatting.

    /# ntpdate
    ntpdate: clock set from pool.ntp.org
    /# date
    Sep 24 21:01:23 UTC 2026        (host said 21:01:26)

The clock does not survive a power cycle - which is exactly what /rc is for:
`ntpdate` there and the machine boots knowing the time.

All of it is bounded subtraction, no long division or shifts: SDCC pulls those
from sm83.lib, whose modules link into the $A000 RAM window. The month tables
are string literals for the same family of reason - an initialized array goes
to _INITIALIZED at $A000 and the image overflows its bank ("buffer too small"
out of makebin), which is how this first failed to link.

1 files changed, 8 insertions, 0 deletions

diff --git a/slosh.layout b/slosh.layout
new file mode 100644
index 0000000..b00c43c
--- /dev/null
+++ b/slosh.layout
@@ -0,0 +1,8 @@
+// What this project needs open, written by `save-workspace`.
+// Checked by `slosh --check`; opened by `open-workspace`.
+layout {
+    tab name="gbos" split="cols" {
+        pane weight=1000 cwd="."
+        pane weight=1000 cwd="." command="tig" suspended=true focus=true
+    }
+}