hex2c.py: Adopt a maximum chunk size

Large segments will be chunked into 32K blocks to they can be handled
seperate. Creating a maximum chunk size allows us to perform a few
tricks in the reloader by allowing us to overwrite parts of the reloader
whilst it is running!

Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>

1 files changed, 11 insertions, 2 deletions

diff --git a/tools/hex2c.py b/tools/hex2c.py
index fa4762c..74f8431 100755
--- a/tools/hex2c.py
+++ b/tools/hex2c.py
@@ -20,7 +20,16 @@ def generate_c(ihex):
     print('};')
     print()
 
-    for i, segment in enumerate(ihex.segments()):
+    segments = []
+    chunk = 32 * 1024
+    for (start, end) in ihex.segments():
+        while start + chunk < end:
+            segments.append((start, start + chunk))
+            start += chunk
+        if start < end:
+            segments.append((start, end))
+
+    for i, segment in enumerate(segments):
         print(f'static const uint8_t segment{i}[] = {{', end='')
 
         for j in range(segment[0], segment[1]):
@@ -30,7 +39,7 @@ def generate_c(ihex):
 
         print('\n};\n')
     print(f'const struct segment segments[] = {{')
-    for i, segment in enumerate(ihex.segments()):
+    for i, segment in enumerate(segments):
         sg = ihex.tobinarray(start=segment[0], end=segment[1]-1)
         crc = binascii.crc32(sg)
         print(f'    0x{segment[0]:08x}, 0x{segment[1]:08x}, 0x{crc:08x}, segment{i},')