Add a read-only version of pal-blockdevice (ARMmbed#126)

* Add a read-only version of pal-blockdevice

To conserve flash space. Reduces the bootloader
size by ~0.8k

* Disable READONLY for tests

Author: LiyouZhou

fix-mbed-os-compile/arm_uc_pal_flashiap_blockdevice_readonly.c

@@ -0,0 +1,23 @@
+#include "update-client-pal-blockdevice/arm_uc_pal_blockdevice_implementation.h"
+#include "update-client-pal-flashiap/arm_uc_pal_flashiap_implementation.h"
+
+#if defined(ARM_UC_USE_PAL_BLOCKDEVICE) && (ARM_UC_USE_PAL_BLOCKDEVICE==1)
+
+extern arm_uc_error_t ARM_UCP_FashIAP_BlockDevice_Initialize(ARM_UC_PAAL_UPDATE_SignalEvent_t callback);
+
+ARM_UC_PAAL_UPDATE ARM_UCP_FLASHIAP_BLOCKDEVICE_READ_ONLY =
+{
+    .Initialize                 = ARM_UCP_FashIAP_BlockDevice_Initialize,
+    .GetCapabilities            = 0,
+    .GetMaxID                   = 0,
+    .Prepare                    = 0,
+    .Write                      = 0,
+    .Finalize                   = 0,
+    .Read                       = ARM_UC_PAL_BlockDevice_Read,
+    .Activate                   = 0,
+    .GetActiveFirmwareDetails   = ARM_UC_PAL_FlashIAP_GetActiveDetails,
+    .GetFirmwareDetails         = ARM_UC_PAL_BlockDevice_GetFirmwareDetails,
+    .GetInstallerDetails        = 0
+};
+
+#endif /* ARM_UC_USE_PAL_BLOCKDEVICE */

source/main.cpp

@@ -49,6 +49,13 @@ const arm_uc_installer_details_t bootloader = {
     .layout   = BOOTLOADER_STORAGE_LAYOUT
 };
 
+/* use a cut down version of ARM_UCP_FLASHIAP_BLOCKDEVICE to reduce
+   binary size if ARM_UC_USE_PAL_BLOCKDEVICE is set and not running tests */
+#if defined(ARM_UC_USE_PAL_BLOCKDEVICE) && (ARM_UC_USE_PAL_BLOCKDEVICE==1) && \
+    (!defined(BOOTLOADER_POWER_CUT_TEST) || (BOOTLOADER_POWER_CUT_TEST != 1))
+#define MBED_CLOUD_CLIENT_UPDATE_STORAGE ARM_UCP_FLASHIAP_BLOCKDEVICE_READ_ONLY
+#endif
+
 #ifdef MBED_CLOUD_CLIENT_UPDATE_STORAGE
 extern ARM_UC_PAAL_UPDATE MBED_CLOUD_CLIENT_UPDATE_STORAGE;
 #else