From 0c5dffe44ee1a13ab38041de73e3d0373458375e Mon Sep 17 00:00:00 2001
From: Nao Pross <naopross@thearcway.org>
Date: Thu, 29 Nov 2018 00:05:39 +0100
Subject: Add b32d for future decoder implementation, update test

---
 .gitignore |  1 +
 b32d.asm   | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 makefile   | 25 +++++++++++++++++++------
 3 files changed, 67 insertions(+), 6 deletions(-)
 create mode 100644 b32d.asm

diff --git a/.gitignore b/.gitignore
index 7fc285c..bedbda2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@ b32e
 b32d
 
 *.o
+*.b32
diff --git a/b32d.asm b/b32d.asm
new file mode 100644
index 0000000..aa7582b
--- /dev/null
+++ b/b32d.asm
@@ -0,0 +1,47 @@
+section .bss
+
+input_buffer resb 8
+output_buffer resb 8
+
+section .text
+global _start
+
+; read_input
+; reads 5 bytes (40 bits) of input
+; uses reg: rax, rdi, rsi, rdx
+; uses mem: input_buffer
+read_input:
+    ; linux x64 read(stdin, input_buffer, 5)
+    mov rax, 0
+    mov rdi, 0
+    mov rsi, input_buffer
+    mov rdx, 5
+    syscall
+    ret
+
+; write_output
+; writes the output buffer to stdout
+; uses reg: rax, rdi, rsi, rdx
+; uses mem: output_buffer(ro)
+write_output:
+    ; linux x64 write(stdout, output_buffer, 8)
+    mov rax, 1
+    mov rdi, 1
+    mov rsi, output_buffer
+    mov rdx, 8
+    syscall
+    ret
+
+; b32d
+; decodes 8 RFC4648 characters without checking its validity (!!!)
+; uses reg:
+; uses mem: input_buffer, output_buffer
+b32d:
+    ret
+
+_start:
+.exit:
+    ; linux x64 exit(0)
+    mov rax, 60
+    mov rdi, 0
+    syscall
diff --git a/makefile b/makefile
index bc75f79..bf4860b 100644
--- a/makefile
+++ b/makefile
@@ -1,15 +1,28 @@
-all: b32e
-	# test b32e hello
-	echo -n "hello" | ./b32e
-	@printf '\n'
-	echo -n "hello" | base32 -i
+.PHONY: all
+all: b32e b32d
 
+.PHONY: test
+test: b32e b32d
+	cat makefile | ./b32e > makefile.b32
+	cat makefile | base32 -w 0 > makefile.check.b32
+
+	cat makefile.b32 | ./b32d
+	cat makefile.check.b32 | base32 -d
+
+# encoder
 b32e: b32e.o
 	ld -o $@ $<
 
 b32e.o: b32e.asm
 	nasm -f elf64 -g -F dwarf -O0 -w+all -o $@ $<
 
+# decoder
+b32d: b32d.o
+	ld -o $@ $<
+
+b32d.o: b32d.asm
+	nasm -f elf64 -g -F dwarf -O0 -w+all -o $@ $<
+
 .PHONY: clean
 clean:
-	rm -f *.o b32e b32d
+	rm -f *.o b32e b32d *.b32
-- 
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