1 files changed, 70 insertions, 0 deletions
diff --git a/tools/mwasmarm_patcher/mwasmarm_patcher.c b/tools/mwasmarm_patcher/mwasmarm_patcher.c
new file mode 100644
index 00000000..0d7470df
--- /dev/null
+++ b/tools/mwasmarm_patcher/mwasmarm_patcher.c
@@ -0,0 +1,70 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <openssl/sha.h>
+#include <string.h>
+#include <stdarg.h> 
+#include <stdlib.h>
+
+// mwasmarm patcher v1.0
+// Patches the Metrowerk C compiler assembler to stop the line ending bug.
+
+char mwasmarm_unpatched_sha1[] = "9d63877c776245129b4727b41d3e9e63cfc9cd28";
+char mwasmarm_patched_sha1[]   = "f5dea73bf90791e104cb59458bebae8b08a55484";
+
+void fatal_printf(char *str, ...) {
+    va_list args;
+    va_start(args, str);
+    vprintf(str, args);
+    va_end(args);
+    exit(1);
+}
+
+// return size in bytes
+int get_file_size (FILE * fp) {
+    int curpos = ftell(fp);
+    fseek(fp, 0, SEEK_END);
+    int result = ftell(fp);
+    fseek(fp, curpos, SEEK_SET);
+    return result;
+}
+
+void print_help(void) {
+    printf("mwasmarm patcher usage: input (example: mwasmarm_patcher mwasmarm.exe)\n");
+}
+
+int main(int argc, char *argv[]) {
+    unsigned char temp[SHA_DIGEST_LENGTH];
+    char buf[SHA_DIGEST_LENGTH*2];
+
+    if (argc != 2) {
+        print_help();
+    } else {
+        // Open the file and sha1 read it.
+        FILE *f = fopen(argv[1], "rb+");
+        if(f == NULL) {
+            fatal_printf("ERROR: No file detected\n");
+        }
+        int fsize = get_file_size(f);
+        char *string = malloc(fsize + 1);
+        fread(string, 1, fsize, f);
+        
+        // Check if sha1 matches either known assembler hashes.
+        SHA1(string, fsize, temp);
+        
+        for (int i=0; i < SHA_DIGEST_LENGTH; i++) {
+            sprintf((char*)&(buf[i*2]), "%02x", temp[i]);
+        }
+        
+        if(!strcmp(buf, mwasmarm_unpatched_sha1)) {
+            // Unpatched, perform the patch.
+            fseek(f, 0x57644, SEEK_SET);
+            fputc(0x05, f);
+            printf("Supported unpatched version detected: assembler patched\n");
+        } else if(!strcmp(buf, mwasmarm_patched_sha1)) {
+            printf("Supported patched version detected: no action needed\n");
+        } else {
+            fatal_printf("ERROR: Unsupported mwasmarm.exe version\n");
+        }
+    }
+    return 0;
+}