Add #ifndef in generic.h, so we can override without local.mk

[0x3333]

Currently, if you want to override, for example, APP_BASE_ADDRESS, you have to create another target, as it is not guarded by #ifndef on generic.h file.

Would be nice if we could guard all config defines by #ifndef so we could run as:

make TARGET=STM32F103 LDSCRIPT='../../some.ld' CFLAGS='-DAPP_BASE_ADDRESS=0x08004000'

Which would relocate the app base without a new target or touching the repo. Helps when you have a board with some specificities that don't need to fork the dapboot repo.

generic/config.h would look like:

/*
 * Copyright (c) 2016, Devan Lai
 *
 * Permission to use, copy, modify, and/or distribute this software
 * for any purpose with or without fee is hereby granted, provided
 * that the above copyright notice and this permission notice
 * appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef CONFIG_H_INCLUDED
#define CONFIG_H_INCLUDED

#ifndef APP_BASE_ADDRESS
#define APP_BASE_ADDRESS 0x08002000
#endif
#ifndef FLASH_SIZE_OVERRIDE
#define FLASH_SIZE_OVERRIDE 0x20000
#endif
#ifndef FLASH_PAGE_SIZE
#define FLASH_PAGE_SIZE  1024
#endif
#ifndef DFU_UPLOAD_AVAILABLE
#define DFU_UPLOAD_AVAILABLE 1
#endif
#ifndef DFU_DOWNLOAD_AVAILABLE
#define DFU_DOWNLOAD_AVAILABLE 1
#endif

#ifndef HAVE_LED
#define HAVE_LED 0
#endif

#ifndef HAVE_BUTTON
#define HAVE_BUTTON 0
#endif

#ifndef BUTTON_SAMPLE_DELAY_CYCLES
#define BUTTON_SAMPLE_DELAY_CYCLES 1440000
#endif

#ifndef HAVE_USB_PULLUP_CONTROL
#define HAVE_USB_PULLUP_CONTROL 0
#endif

#endif

If you are OK with it, I'm glad to provide a PR.

[devanlai]

This seems like a good idea - I'm all for it.

[0x3333]

Great, will check if doesn't affect other parts, and issue a PR. Thanks.