From 868844f71007e4bcee508f51f362968ef77a6a3f Mon Sep 17 00:00:00 2001
From: pantonshire <tom@tomandtally.co.uk>
Date: Sat, 26 Jul 2025 15:43:02 +0100
Subject: [PATCH] add calling convention notes

---
 docs/call_conv.md | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100644 docs/call_conv.md

diff --git a/docs/call_conv.md b/docs/call_conv.md
new file mode 100644
index 0000000..c7e7d9a
--- /dev/null
+++ b/docs/call_conv.md
@@ -0,0 +1,10 @@
+# Calling convention
+## boot0
+I'm not sticking to any particular calling convention for boot0, since we have to golf to fit in
+440 bytes. Whatever's most convenient.
+
+## boot1
+- Arguments: ax, cx, dx, stack
+- Return value: ax, cf for booleans
+- ax may be clobbered. All other registers are preserved
+- Callee cleanup (i.e. the function pops stack arguments when returning)