From afff7616373801fdc4f5184d72a15b3160355cab Mon Sep 17 00:00:00 2001
From: s-ol <s+removethis@s-ol.nu>
Date: Tue, 6 Jul 2021 14:33:03 +0200
Subject: fix hello_world comments

---
 hello_world.subv | 13 ++++++-------
 qemu.sh          |  2 +-
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/hello_world.subv b/hello_world.subv
index 60d9065..579a0e6 100644
--- a/hello_world.subv
+++ b/hello_world.subv
@@ -1,14 +1,13 @@
 == code 0x80000000
-  # load mhartid CSR into t0, trap all but first Hart
-  73/system 5/rd/t0 2/funct3/csrrs 0/rs/x0 f14/imm12/mhartid 
-  63/branch 1/subop/!= 5/rs/t0 0/rs/x0 0/off13
+  # trap all but first Hart (a0 = mhartid)
+  63/branch 1/subop/!= a/rs/a0 0/rs/x0 0/off13
 
 main:
-  # x4 = &message
+  # a0 = &message
   # . load high bits
   37/lui a/rd/a0 Message/imm20hi
   # . add low bits
-  13/opi 0/subop/add 4/rd/x4 a/rs/a0 Message/imm12lo
+  13/opi 0/subop/add a/rd/a0 a/rs/a0 Message/imm12lo
   # call print
   6f/jal 1/rd/ra print/off21
 loop:
@@ -19,7 +18,7 @@ print:
   # load 0x10010000 (UART0) into t0
   37/lui 5/rd/t0 0x10010/imm20
 print:loop:
-  # load unsigned byte at x4
+  # load unsigned byte at a0
   03/load 4/subop/byte 6/rd/t1 a/rs/a0 0/imm12
   # break loop if zero
   63/branch 0/subop/== 6/rs/t1 0/rs/x0 print:break/off13
@@ -29,7 +28,7 @@ print:spin:
   63/branch 4/subop/< 7/rs/t2 0/rs/x0 print:spin/off13
   # print char
   23/store 2/width/word 5/rs/t0 6/rs/t1 0/off12
-  # increment x4
+  # increment a0
   13/opi 0/subop/add a/rd/a0 a/rs/a0 1/imm12
   # jump back up
   6f/jal 0/rd/x0 print:loop/off21
diff --git a/qemu.sh b/qemu.sh
index 07af0d8..ef6616b 100755
--- a/qemu.sh
+++ b/qemu.sh
@@ -1,2 +1,2 @@
 #!/bin/sh
-qemu-system-riscv32 -nographic -machine sifive_u -bios none -kernel "$@"
+exec qemu-system-riscv32 -nographic -machine sifive_u -bios none -kernel "$@"
-- 
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