Compress base.img using FastLZ library

2025-11-09 21:38:27 +01:00
parent e4a5c07b3d
commit 02d60129b1
58 changed files with 3676 additions and 10 deletions
--- a/FastLZ/tests/refimpl.c
+++ b/FastLZ/tests/refimpl.c
@ -0,0 +1,103 @@
+#include <stdint.h>
+
+/*
+ * Workaround for DJGPP to find uint8_t, uint16_t, etc.
+ */
+#if defined(__MSDOS__) && defined(__GNUC__)
+#include <stdint-gcc.h>
+#endif
+
+void REF_Level1_decompress(const uint8_t* input, int length, uint8_t* output) {
+  int src = 0;
+  int dest = 0;
+  while (src < length) {
+    int type = input[src] >> 5;
+    if (type == 0) {
+      /* literal run */
+      int run = 1 + input[src];
+      src = src + 1;
+      while (run > 0) {
+        output[dest] = input[src];
+        src = src + 1;
+        dest = dest + 1;
+        run = run - 1;
+      }
+    } else if (type < 7) {
+      /* short match */
+      int ofs = 256 * (input[src] & 31) + input[src + 1];
+      int len = 2 + (input[src] >> 5);
+      src = src + 2;
+      int ref = dest - ofs - 1;
+      while (len > 0) {
+        output[dest] = output[ref];
+        ref = ref + 1;
+        dest = dest + 1;
+        len = len - 1;
+      }
+    } else {
+      /* long match */
+      int ofs = 256 * (input[src] & 31) + input[src + 2];
+      int len = 9 + input[src + 1];
+      src = src + 3;
+      int ref = dest - ofs - 1;
+      while (len > 0) {
+        output[dest] = output[ref];
+        ref = ref + 1;
+        dest = dest + 1;
+        len = len - 1;
+      }
+    }
+  }
+}
+
+void REF_Level2_decompress(const uint8_t* input, int length, uint8_t* output) {
+  int src = 0;
+  int dest = 0;
+  while (src < length) {
+    int type = input[src] >> 5;
+    if (type == 0) {
+      /* literal run */
+      int run = 1 + input[src];
+      src = src + 1;
+      while (run > 0) {
+        output[dest] = input[src];
+        src = src + 1;
+        dest = dest + 1;
+        run = run - 1;
+      }
+    } else {
+      int next = 2;
+      int len = 2 + (input[src] >> 5);
+      if (len == 9) {
+        /* long match */
+        next = next + 1;
+        len = len + input[src + 1];
+        if (len == 9 + 255) {
+          /* Gamma code for match length */
+          int nn = input[src + 1];
+          while (nn == 255) {
+            nn = input[src + next - 1];
+            next = next + 1;
+            len += nn;
+          }
+        }
+      }
+
+      int ofs = 256 * (input[src] & 31) + input[src + next - 1];
+      if (ofs == 8191) {
+        /* match from 16-bit distance */
+        ofs += 256 * input[src + next] + input[src + next + 1];
+        next = next + 2;
+      }
+      src = src + next;
+
+      int ref = dest - ofs - 1;
+      while (len > 0) {
+        output[dest] = output[ref];
+        ref = ref + 1;
+        dest = dest + 1;
+        len = len - 1;
+      }
+    }
+  }
+}