Move max image sector config to mcuboot_config.h

Take the opportunity to clean up a bit of platform cruft that has
gotten into bootutil by moving it to mcuboot_config.h, and ensuring it
is documented in the template config file.

Signed-off-by: Marti Bolivar <marti@opensourcefoundries.com>

boot/bootutil/src/bootutil_priv.h

@@ -91,15 +91,7 @@ struct boot_swap_state {
     uint8_t image_ok;
 };
 
-#if defined(__BOOTSIM__)
-#define BOOT_MAX_IMG_SECTORS       128
-#elif defined(__ZEPHYR__)
-#define BOOT_MAX_IMG_SECTORS       CONFIG_BOOT_MAX_IMG_SECTORS
-#elif defined(MCUBOOT_MYNEWT)
-#define BOOT_MAX_IMG_SECTORS       MYNEWT_VAL(BOOTUTIL_MAX_IMG_SECTORS)
-#else
-#error "Invalid target OS"
-#endif
+#define BOOT_MAX_IMG_SECTORS       MCUBOOT_MAX_IMG_SECTORS
 
 /*
  * The current flashmap API does not check the amount of space allocated when

boot/mynewt/mcuboot_config/include/mcuboot_config/mcuboot_config.h

@@ -52,4 +52,6 @@
 #define MCUBOOT_OVERWRITE_ONLY_FAST 1
 #endif
 
+#define MCUBOOT_MAX_IMG_SECTORS       MYNEWT_VAL(BOOTUTIL_MAX_IMG_SECTORS)
+
 #endif /* __MCUBOOT_CONFIG_H__ */

boot/zephyr/include/mcuboot_config/mcuboot_config.h

@@ -48,6 +48,8 @@
  */
 #define MCUBOOT_USE_FLASH_AREA_GET_SECTORS
 
+#define MCUBOOT_MAX_IMG_SECTORS       CONFIG_BOOT_MAX_IMG_SECTORS
+
 #endif /* !__BOOTSIM__ */
 
 #endif /* __MCUBOOT_CONFIG_H__ */

samples/mcuboot_config/mcuboot_config.template.h

@@ -78,4 +78,8 @@
  * See the flash APIs for more details. */
 /* #define MCUBOOT_USE_FLASH_AREA_GET_SECTORS */
 
+/* Default maximum number of flash sectors per image slot; change
+ * as desirable. */
+#define MCUBOOT_MAX_IMG_SECTORS 128
+
 #endif /* __MCUBOOT_CONFIG_H__ */

sim/mcuboot-sys/build.rs

@@ -17,6 +17,7 @@ fn main() {
     let mut conf = gcc::Build::new();
     conf.define("__BOOTSIM__", None);
     conf.define("MCUBOOT_USE_FLASH_AREA_GET_SECTORS", None);
+    conf.define("MCUBOOT_MAX_IMG_SECTORS", Some("128"));
 
     if validate_slot0 {
         conf.define("MCUBOOT_VALIDATE_SLOT0", None);