From f32a27ff15aaa651aba2b7a2af73edae79d4fd30 Mon Sep 17 00:00:00 2001
From: BlackMark <me@blackmark.me>
Date: Sun, 19 Jul 2026 14:55:01 +0200
Subject: [PATCH] tsb: use the named register surface

Direct register access now reads through the named surface
(hw::mcusr::wdrf.test(), hw::ucsr0b::write(...)) instead of the string form,
matching how libavr itself is written. Zero-overhead: pure 740 B, tricks 658 B,
asm 508 B unchanged, all byte-identical across modes, protocol green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 tsb/tsb_asm.cpp    | 11 +++++------
 tsb/tsb_pure.cpp   |  2 +-
 tsb/tsb_tricks.cpp |  2 +-
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/tsb/tsb_asm.cpp b/tsb/tsb_asm.cpp
index 02e2054..854c4c1 100644
--- a/tsb/tsb_asm.cpp
+++ b/tsb/tsb_asm.cpp
@@ -237,10 +237,9 @@ void write_config()
 	// Minimal 115200 8N1 bring-up: 8N1 is the UCSR0C reset value, so only U2X0,
 	// UBRR0 (16 at 16 MHz → 2.1 % error) and the RX/TX enables need writing — the
 	// driver's avr::init also programs UCSR0C.
-	avr::hw::reg<"UCSR0A">::write(avr::hw::field<"UCSR0A", "U2X0">{}(1).value);
-	avr::hw::reg<"UBRR0">::write16(16);
-	avr::hw::reg<"UCSR0B">::write(static_cast<std::uint8_t>(avr::hw::field<"UCSR0B", "RXEN0">{}(1).value |
-	                                                        avr::hw::field<"UCSR0B", "TXEN0">{}(1).value));
+	avr::hw::ucsr0a::write(avr::hw::ucsr0a::u2x0(1).value);
+	avr::hw::ubrr0::write16(16);
+	avr::hw::ucsr0b::write(avr::hw::ucsr0b::rxen0(1), avr::hw::ucsr0b::txen0(1));
 
 	// The password gate that the canonical loader carries (compare host bytes
 	// against the config page, hang on mismatch) is dropped here: it is optional
@@ -250,8 +249,8 @@ void write_config()
 	std::uint8_t knocks = 0;
 	std::uint16_t idle = 0xFFFF;
 	while (knocks < 3) {
-		if (avr::hw::reg<"UCSR0A">::read() & avr::hw::field<"UCSR0A", "RXC0">{}(1).value)
-			knocks = avr::hw::reg<"UDR0">::read() == '@' ? knocks + 1 : 0;
+		if (avr::hw::ucsr0a::rxc0.test())
+			knocks = avr::hw::udr0::read() == '@' ? knocks + 1 : 0;
 		else if (--idle == 0)
 			appjump();
 	}
diff --git a/tsb/tsb_pure.cpp b/tsb/tsb_pure.cpp
index bc8004d..b26cb64 100644
--- a/tsb/tsb_pure.cpp
+++ b/tsb/tsb_pure.cpp
@@ -201,7 +201,7 @@ void write_config()
 {
 	// A bootloader may be entered by a watchdog reset; the reference loader
 	// hands straight back to the application in that case rather than run.
-	if (avr::hw::field<"MCUSR", "WDRF">::test())
+	if (avr::hw::mcusr::wdrf.test())
 		appjump();
 
 	avr::init<serial_t>();
diff --git a/tsb/tsb_tricks.cpp b/tsb/tsb_tricks.cpp
index 35e7913..d6f1c90 100644
--- a/tsb/tsb_tricks.cpp
+++ b/tsb/tsb_tricks.cpp
@@ -185,7 +185,7 @@ void write_config()
 
 [[noreturn]] void run()
 {
-	if (avr::hw::reg<"MCUSR">::read() & avr::hw::field<"MCUSR", "WDRF">{}(1).value)
+	if (avr::hw::mcusr::read() & avr::hw::mcusr::wdrf(1).value)
 		appjump();
 
 	avr::init<serial_t>();