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/****************************************************************************
* Copyright (C) 2016-2018 Sebastien Lorquet. All rights reserved.
* Author: Sebastien Lorquet <sebastien@lorquet.fr>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
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#define BOOT_STACKSIZE (16 * 1024)
#define BOOT_STACK ((unsigned)&_ebss+ BOOT_STACKSIZE-4)
#define BOOT_PERIPHERAL_INTERRUPTS 16
/****************************************************************************
* Public Functions
****************************************************************************/
/* Chip-specific entrypoint */
extern void __boot_start(void);
/* Common exception entrypoint */
extern void __boot_exception_common(void);
/************************************************************************************
* Public data
************************************************************************************/
/* Provided by the linker script to indicate the end of the BSS and start of text */
extern char _ebss;
extern char _stext;
/* The v7m vector table consists of an array of function pointers, with the first
* slot (vector zero) used to hold the initial stack pointer.
*
* As all exceptions (interrupts) are routed via exception_common, we just need to
* fill this array with pointers to it.
*
* Note that the [ ... ] designated initialiser is a GCC extension.
*/
unsigned __boot_vectors[] __attribute__((section(".boot.vectors"))) =
{
BOOT_STACK, /* Initial stack */
(unsigned)&__boot_start, /* Reset exception handler */
/* Vectors 2 - n point directly at the generic handler */
[2 ... (15 + BOOT_PERIPHERAL_INTERRUPTS)] = (unsigned)&__boot_exception_common
};
/* ------------------------------------------------------------------------- */
BOOTCODE __attribute__((naked)) void __boot_app(void)
{
__asm__ __volatile__ ("\t"
/* load SP (from 08004000) */
"movw r0, #0x4000 \n\t"
"movt r0, #0x0800 \n\t"
"ldr sp, [r0] \n\t"
/* load LR (from 08004004) */
"movw r0, #0x4004 \n\t"
"movt r0, #0x0800 \n\t"
"ldr r0, [r0] \n\t"
"mov lr, r0 \n\t"
/* setup VTOR (at E000ED08) to remap vectors*/
"movw r0, #0xED08 /*adr lo*/ \n\t"
"movt r0, #0xE000 /*adr hi*/ \n\t"
"movw r1, #0x4000 /*val lo*/ \n\t"
"movt r1, #0x0800 /*val hi*/ \n\t"
"str r1, [r0] /*store value at address*/ \n\t"
"bx lr /*take the jump*/ \n"
);
}
/* ------------------------------------------------------------------------- */
BOOTCODE void __boot_start(void)
{
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bool has_update = false;
bool do_app = true;
bootloader_inithardware();
retry:
if(bootloader_button())
{
/* Boot button is pressed -> dont boot app, do a download */
do_app = false;
has_update = false;
}
else
{
/* Button not pressed: normal process */
has_update = bootloader_checkupdate();
}
if(has_update)
{
do_app = bootloader_apply(); /* If app was updated, only boot if update was successful */
}
if(do_app)
{
/* Boot app if, no update, or button not pressed, or update and it was successful */
bootloader_stophardware();
__boot_app();
}
else
{
bootloader_download();
goto retry;
}
/* ------------------------------------------------------------------------- */