From 15de101004764e23c5929413b7a854ec68c82063 Mon Sep 17 00:00:00 2001
From: Anton <anton.frappe@outlook.com>
Date: Wed, 3 Mar 2021 16:48:20 +0100
Subject: [PATCH] bare2_2
---
examples/rtic_bare2.rs | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/examples/rtic_bare2.rs b/examples/rtic_bare2.rs
index d4dc217..0c88115 100644
--- a/examples/rtic_bare2.rs
+++ b/examples/rtic_bare2.rs
@@ -109,7 +109,14 @@ fn wait(i: u32) {
//
// Dump generated assembly for the "wait" function.
//
-// ** your answer here **
+// => 0x080004a0 <+0>: push {r7, lr}
+// 0x080004a2 <+2>: mov r7, sp
+// 0x080004a4 <+4>: movw r0, #16960 ; 0x4240
+// 0x080004a8 <+8>: movt r0, #15
+// 0x080004ac <+12>: nop
+// 0x080004ae <+14>: subs r0, #1
+// 0x080004b0 <+16>: bne.n 0x80004ac <rtic_bare2::wait+12>
+// 0x080004b2 <+18>: pop {r7, pc}
//
// Under the ARM calling convention, r0.. is used as arguments.
// However in this case, we se that r0 is set by the assembly instructions,
@@ -119,7 +126,9 @@ fn wait(i: u32) {
//
// Answer in your own words, how they assign r0 to 1000000.
//
-// ** your answer here **
+// movt "loads" the immidiate value to the upper part of the word [31:16].
+// movw "loads" the immidiate value to the lower part of the word [15:0].
+// they are then "or":ed together.
//
// Commit your answers (bare2_2)
//
--
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