From 307d2ddce98ef81f5cd3e5e1f24a7ddada60c486 Mon Sep 17 00:00:00 2001
From: Barry Wardell <rockbox@barrywardell.net>
Date: Wed, 1 Aug 2007 22:13:53 +0000
Subject: Initial version of ARM disassembler by Antonius Hellman.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@14126 a1c6a512-1295-4272-9138-f99709370657
---
 utils/disassembler/arm/main.c | 118 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 118 insertions(+)
 create mode 100644 utils/disassembler/arm/main.c

(limited to 'utils/disassembler/arm/main.c')

diff --git a/utils/disassembler/arm/main.c b/utils/disassembler/arm/main.c
new file mode 100644
index 0000000..834dc5f
--- /dev/null
+++ b/utils/disassembler/arm/main.c
@@ -0,0 +1,118 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#define ULONG  unsigned long
+#define USHORT unsigned short
+#define UCHAR  unsigned char
+
+ULONG isdata[1000000]; /* each bit defines one byte as: code=0, data=1 */
+
+extern void dis_asm(ULONG off, ULONG val, char *stg);
+
+void main(int argc, char **argv)
+{
+  FILE   *in, *out;
+  char   *ptr, stg[256];
+  ULONG  pos, sz, val, loop;
+  int    offset, offset1;
+  USHORT regid;
+
+  if(argc == 1 || strcmp(argv[1], "--help") == 0)
+  { printf("Usage: arm_disass [input file]\n");
+    printf(" disassembles input file to 'disasm.txt'");
+    exit(-1);
+  }
+
+  in = fopen(argv[1], "rb");
+  if(in == NULL)
+  { printf("Cannot open %s", argv[1]);
+    exit(-1);
+  }
+
+  out = fopen("disasm.txt", "w");
+  if(out == NULL) exit(-1);
+
+  fseek(in, 0, SEEK_END);
+  sz = ftell(in);
+
+  /* first loop only sets data/code tags */
+  for(loop=0; loop<2; loop++)
+  {
+    for(pos=0; pos<sz; pos+=4)
+    {
+      /* clear disassembler string start */
+      memset(stg, 0, 40);
+      /* read next code dword */
+      fseek(in, pos, SEEK_SET);
+      fread(&val, 4, 1, in);
+
+      /* check for data tag set: if 1 byte out of 4 is marked => assume data */
+      if((isdata[pos>>5] & (0xf << (pos & 31))) || (val & 0xffff0000) == 0)
+      {
+        sprintf(stg, "%6x:	%08x", pos, val);
+      }
+      else
+      {
+        dis_asm(pos, val, stg);
+
+        /* check for instant mov operation */
+        if(memcmp(stg+17, "mov ", 4) == 0 && (ptr=strstr(stg, "0x")) != NULL)
+        {
+          regid = *(USHORT*)(stg+22);
+
+          sscanf(ptr+2, "%x", &offset);
+          if(ptr[-1] == '-')
+            offset = -offset;
+        }
+        else
+        /* check for add/sub operation */
+        if((ptr=strstr(stg, "0x")) != NULL
+         && (memcmp(stg+17, "add ", 4) == 0 || memcmp(stg+17, "sub ", 4) == 0))
+        {
+          if(regid == *(USHORT*)(stg+22) && regid == *(USHORT*)(stg+26))
+          {
+            sscanf(ptr+2, "%x", &offset1);
+            if(ptr[-1] == '-')
+              offset1 = -offset1;
+
+            if(memcmp(stg+17, "add ", 4) == 0) offset += offset1;
+            else                               offset -= offset1;
+
+            /* add result to disassembler string */
+            sprintf(stg+strlen(stg), " <- 0x%x", offset);
+          }
+          else
+            regid = 0;
+        }
+        else
+          regid = 0;
+
+        /* check for const data */
+        if(memcmp(stg+26, "[pc, ", 5) == 0 && (ptr=strstr(stg, "0x")) != NULL)
+        {
+          sscanf(ptr+2, "%x", &offset);
+          if(ptr[-1] == '-')
+            offset = -offset;
+
+          /* add data tag */
+          isdata[(pos+offset+8)>>5] |= 1 << ((pos+offset+8) & 31);
+
+          /* add const data to disassembler string */
+          fseek(in, pos+offset+8, SEEK_SET);
+          fread(&offset, 4, 1, in);
+          sprintf(stg+strlen(stg), " <- 0x%x", offset);
+        }
+      }
+    
+      /* remove trailing spaces */
+      while(stg[strlen(stg)-1] == 32)
+        stg[strlen(stg)-1] = 0;
+
+      if(loop == 1)
+        fprintf(out, "%s\n", stg);
+    }
+  }
+
+  fclose(in);
+}
\ No newline at end of file
-- 
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