From de0e42142beb43d0be8fb6fe4295b4f20578ce84 Mon Sep 17 00:00:00 2001
From: Andre Richter <andre.o.richter@gmail.com>
Date: Mon, 2 Apr 2018 17:44:05 +0200
Subject: [PATCH] stay closer to original

---
 03_uart1/src/main.rs |   1 +
 05_uart0/kernel8.img | Bin 2040 -> 2080 bytes
 05_uart0/src/main.rs |   3 +++
 05_uart0/src/uart.rs |   3 +++
 4 files changed, 7 insertions(+)

diff --git a/03_uart1/src/main.rs b/03_uart1/src/main.rs
index 660261e8..012e54a2 100644
--- a/03_uart1/src/main.rs
+++ b/03_uart1/src/main.rs
@@ -42,6 +42,7 @@ fn main() {
     uart.getc(); // Press a key first before being greeted
     uart.puts("Hello Rustacean!\n");
 
+    // echo everything back
     loop {
         uart.send(uart.getc());
     }
diff --git a/05_uart0/kernel8.img b/05_uart0/kernel8.img
index fe9766c13a12d7d9e92ae56fd45ca214e35b15ee..0f7e74d77e20650888d4442178dcab39d8ffe57a 100755
GIT binary patch
delta 247
zcmeytzd&Gu4CCpIvd+vxa~K$=a56AV-~wWWmj`Vf-%c)KE@N8AHTe~DI_JlOwjc?|
zr<0>t+7%t-Cn_;D1U*P*nt1Ww|LHH78I9_hII<TqF@!JzRVlViW@6PgxFJ6gq~Z}X
zgAveRk<ZoME58PNt^Ci-Jh2YQ2dlgTRl_c8v~{v2Yw_j-tc{EYoGw2#d0l?mGjhB>
z#J~^&au%5H%CG|@cKHAQkbnI0KOQj4uX+f?ZzdPAmuZIPB_`#hDwO0a6qcqIRVoyx
T7G);pC~`3<aBwhy0E`9zKdDjd

delta 208
zcmZ1=@PmJX4CC>Qvd+vxGZ+}Aa56AV-~wWWrw45vUrsJ!E@M*UoBWD7o%8KMTabj~
z!^u%B?TQTY6P1`6f*vF@O}zN;|MVBkj7IfL9NCIY3?Ym_Rf;Z?nOL=XX2?$jsd&W9
zV6<;?ENijI=W6ejUxU3?{%2;M7{|aM!T<!DFR(T;8hmyBsrl3Sr#&Ob>q86-As}~v
o`K}B*Kw^jg{}1`cFaP5Kv;3-uK>T5HBYT-30|N&K$Ot$M0K!~Ez5oCK

diff --git a/05_uart0/src/main.rs b/05_uart0/src/main.rs
index 2d4da612..2d90506f 100644
--- a/05_uart0/src/main.rs
+++ b/05_uart0/src/main.rs
@@ -72,8 +72,11 @@ fn main() {
         uart.hex(mbox.buffer[6]);
         uart.hex(mbox.buffer[5]);
         uart.puts("\n");
+    } else {
+        uart.puts("Unable to query serial!\n");
     }
 
+    // echo everything back
     loop {
         uart.send(uart.getc());
     }
diff --git a/05_uart0/src/uart.rs b/05_uart0/src/uart.rs
index bb526696..c410c1cc 100644
--- a/05_uart0/src/uart.rs
+++ b/05_uart0/src/uart.rs
@@ -173,8 +173,11 @@ impl Uart {
         let mut n;
 
         for i in 0..8 {
+            // get highest tetrad
             n = d.wrapping_shr(28 - i * 4) & 0xF;
 
+            // 0-9 => '0'-'9', 10-15 => 'A'-'F'
+            // Add proper offset for ASCII table
             if n > 9 {
                 n += 0x37;
             } else {