Make swap RAM buffer size configurable

Author: pennam

boot/bootutil/include/bootutil/bootutil_public.h

@@ -82,6 +82,14 @@ extern "C" {
 #define BOOT_MAGIC_ALIGN_SIZE   BOOT_MAGIC_SZ
 #endif
 
+#ifdef MCUBOOT_SWAP_BUF_SIZE
+#define BOOT_SWAP_BUF_SIZE MCUBOOT_SWAP_BUF_SIZE
+#elif BOOT_MAX_ALIGN > 1024
+#define BOOT_SWAP_BUF_SIZE BOOT_MAX_ALIGN
+#else
+#define BOOT_SWAP_BUF_SIZE 1024
+#endif
+
 #define BOOT_MAGIC_GOOD     1
 #define BOOT_MAGIC_BAD      2
 #define BOOT_MAGIC_UNSET    3

boot/bootutil/src/loader.c

@@ -924,7 +924,7 @@ boot_copy_region(struct boot_loader_state *state,
     uint8_t image_index;
 #endif
 
-    TARGET_STATIC uint8_t buf[1024] __attribute__((aligned(4)));
+    TARGET_STATIC uint8_t buf[BOOT_SWAP_BUF_SIZE] __attribute__((aligned(4)));
 
 #if !defined(MCUBOOT_ENC_IMAGES)
     (void)state;

boot/mbed/mbed_lib.json

@@ -214,6 +214,12 @@
             "macro_name": "MCUBOOT_INCLUDE_KEYS",
             "accepted_values": [true, null],
             "value": null
+        },
+        "swap-buf-size": {
+            "help": "Specify swap ram buffer size.",
+            "macro_name": "MCUBOOT_SWAP_BUF_SIZE",
+            "accepted_values": [1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072],
+            "value": null
         }
     }
 }