From 71505bc8b94796f473b79fc3ef2f5c9250c0bed4 Mon Sep 17 00:00:00 2001
From: fosslinux <fosslinux@aussies.space>
Date: Fri, 12 Feb 2021 17:56:32 +1100
Subject: [PATCH] Add fletcher16 impl to mescc-tools-extra

---
 sysa/mescc-tools-extra/mescc-tools-extra.kaem |  37 +++++++
 sysa/mescc-tools-extra/src/fletcher16.c       | 103 ++++++++++++++++++
 2 files changed, 140 insertions(+)
 create mode 100644 sysa/mescc-tools-extra/src/fletcher16.c

diff --git a/sysa/mescc-tools-extra/mescc-tools-extra.kaem b/sysa/mescc-tools-extra/mescc-tools-extra.kaem
index 5616587..e2a0727 100755
--- a/sysa/mescc-tools-extra/mescc-tools-extra.kaem
+++ b/sysa/mescc-tools-extra/mescc-tools-extra.kaem
@@ -87,4 +87,41 @@ hex2 \
     -o ${bindir}/chmod \
     --exec_enable
 
+# fletcher16 command
+M2-Planet \
+    -f /M2-Planet/test/common_x86/functions/file.c \
+    -f /M2-Planet/test/common_x86/functions/exit.c \
+    -f functions/numerate_number.c \
+    -f functions/string.c \
+    -f functions/file_print.c \
+    -f functions/match.c \
+    -f functions/require.c \
+    -f functions/in_set.c \
+    -f /M2-Planet/functions/calloc.c \
+    -f /M2-Planet/test/common_x86/functions/malloc.c \
+    -f fletcher16.c \
+    --architecture x86 \
+    --debug \
+    -o fletcher16.M1
+
+blood-elf -f fletcher16.M1 -o fletcher16-footer.M1
+
+M1 \
+    -f /M2-Planet/test/common_x86/x86_defs.M1 \
+    -f /M2-Planet/test/common_x86/libc-core.M1 \
+    -f fletcher16.M1 \
+    -f fletcher16-footer.M1 \
+    --LittleEndian \
+    --architecture x86 \
+    -o hold
+
+hex2 \
+    -f /M2-Planet/test/common_x86/ELF-i386-debug.hex2 \
+    -f hold \
+    --LittleEndian \
+    --architecture x86 \
+    --BaseAddress 0x8048000 \
+    -o ${bindir}/fletcher16 \
+    --exec_enable
+
 cd ..
diff --git a/sysa/mescc-tools-extra/src/fletcher16.c b/sysa/mescc-tools-extra/src/fletcher16.c
new file mode 100644
index 0000000..35237c5
--- /dev/null
+++ b/sysa/mescc-tools-extra/src/fletcher16.c
@@ -0,0 +1,103 @@
+/*
+ * SPDX-FileCopyrightText: 2021 fosslinux <fosslinux@aussies.space>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#define BUF_SIZE 1024
+// CONSTANT BUF_SIZE 1024
+#define PATH_MAX 512
+// CONSTANT PATH_MAX 512
+
+int fletch16(FILE* fp)
+{
+	long sum1 = 0;
+	long sum2 = 0;
+	int index;
+	int c = fgetc(fp);
+	while(c != EOF)
+	{
+		sum1 = (sum1 + c) % 255;
+		sum2 = (sum2 + sum1) % 255;
+		c = fgetc(fp);
+	}
+
+	return (sum2 << 8) | sum1;
+}
+
+int main(int argc, char** argv)
+{
+	/* Open the file containing the checksums */
+	FILE* check_fp = fopen(argv[1], "r");
+	require(check_fp != NULL, prepend_string(
+			prepend_string("Error opening checksum file ", argv[1]), "\n"));
+	int rc = 0;
+
+	/* Now loop over each one */
+	FILE* fp;
+	char c;
+	char* filename;
+	char* s_rchecksum;
+	char* file;
+	int rchecksum;
+	int i;
+	int csum;
+	/* It's much easier to just break; out of the loop */
+	while(1)
+	{
+		filename = calloc(PATH_MAX, sizeof(char));
+		require(filename != NULL, "Failed to allocate filename\n");
+		s_rchecksum = calloc(16, sizeof(char));
+		require(s_rchecksum != NULL, "Failed to allocate filename\n");
+		/* Read the checksum */
+		c = fgetc(check_fp);
+		i = 0;
+		while (c != ' ' && c != EOF)
+		{
+			require(in_set(c, "0123456789"), "Invalid checksum file\n");
+			s_rchecksum[i] = c;
+			c = fgetc(check_fp);
+			i = i + 1;
+		}
+		if(c == EOF) break;
+		/* Skip the space */
+		c = fgetc(check_fp);
+		/* Read the filename */
+		i = 0;
+		while(c != '\n' && c != EOF)
+		{
+			filename[i] = c;
+			c = fgetc(check_fp);
+			i = i + 1;
+		}
+		/* If we got here and it is EOF, we probably have all the needed data */
+		/* Convert s_rchecksum -> int */
+		rchecksum = numerate_string(s_rchecksum);
+
+		/* Now let's actually calculate the real checksum */
+		/* Read the file into a char* array */
+		fp = fopen(filename, "r");
+		/* Calculate the checksum! */
+		csum = fletch16(fp);
+
+		/* Compare */
+		if(csum == rchecksum)
+		{
+			file_print(prepend_string(filename, ": OK\n"), stdout);
+		}
+		else
+		{
+			/* We failed.. we should fail at the end */
+			rc = 1;
+			file_print(prepend_string(filename, ": FAILED\n"), stdout);
+		}
+
+		/* Now if we finished the last one, leave */
+		if(c == EOF) break;
+	}
+
+	return rc;
+}