// finishes up writing to the flash, including adding the tinyVector tables at the end of memory
// TODO: can this be simplified? EG: currentAddress = PROGMEM_SIZE; fillFlashWithVectors();
static inline void tiny85FinishWriting(void) {
// make sure remainder of flash is erased and write checksum and application reset vectors
if (didWriteSomething) {
while (currentAddress < BOOTLOADER_ADDRESS) {
fillFlashWithVectors();
}
}
}
static inline void tiny85FlashWrites(void) {
_delay_us(2000); // TODO: why is this here? - it just adds pointless two level deep loops seems like?
// write page to flash, interrupts will be disabled for > 4.5ms including erase
if (currentAddress % SPM_PAGESIZE) { // when we aren't perfectly aligned to a flash page boundary
fillFlashWithVectors(); // fill up the rest of the page with 0xFFFF (unprogrammed) bits
} else {
writeFlashPage(); // otherwise just write it
}
}
static inline void tiny85FlashInit(void) {
// check for erased first page (no bootloader interrupt vectors), add vectors if missing
// this needs to happen for usb communication to work later - essential to first run after bootloader
// being installed
if(pgm_read_word(RESET_VECTOR_OFFSET * 2) != 0xC000 + (BOOTLOADER_ADDRESS/2) - 1 ||
pgm_read_word(USBPLUS_VECTOR_OFFSET * 2) != 0xC000 + (BOOTLOADER_ADDRESS/2) - 1) {
fillFlashWithVectors();
}
// TODO: necessary to reset currentAddress?
currentAddress = 0;
}
static void eraseApplication(void)
{
// erase all pages starting from end of application section down to page 1 (leaving page 0)
CURRENT_ADDRESS = BOOTLOADER_ADDRESS - SPM_PAGESIZE;
while(CURRENT_ADDRESS != 0x0000)
{
boot_page_erase(CURRENT_ADDRESS);
boot_spm_busy_wait();
CURRENT_ADDRESS -= SPM_PAGESIZE;
}
// erase and load page 0 with vectors
fillFlashWithVectors();
}
// erase any existing application and write in jumps for usb interrupt and reset to bootloader
// - Because flash can be erased once and programmed several times, we can write the bootloader
// - vectors in now, and write in the application stuff around them later.
// - if vectors weren't written back in immidately, usb would fail.
static inline void eraseApplication(void) {
// erase all pages until bootloader, in reverse order (so our vectors stay in place for as long as possible)
// while the vectors don't matter for usb comms as interrupts are disabled during erase, it's important
// to minimise the chance of leaving the device in a state where the bootloader wont run, if there's power failure
// during upload
currentAddress = BOOTLOADER_ADDRESS;
cli();
while (currentAddress) {
currentAddress -= SPM_PAGESIZE;
boot_page_erase(currentAddress);
boot_spm_busy_wait();
}
fillFlashWithVectors();
sei();
}
static inline __attribute__((noreturn)) void leaveBootloader(void)
{
DBG1(0x01, 0, 0);
bootLoaderExit();
cli();
USB_INTR_ENABLE = 0;
USB_INTR_CFG = 0; /* also reset config bits */
#ifdef TINY85MODE
// make sure remainder of flash is erased and write checksum and application reset vectors
if(appWriteComplete)
{
CURRENT_ADDRESS = writeSize;
while(CURRENT_ADDRESS < BOOTLOADER_ADDRESS)
{
fillFlashWithVectors();
}
}
#else
GICR = (1 << IVCE); /* enable change of interrupt vectors */
GICR = (0 << IVSEL); /* move interrupts to application flash section */
#endif
// TODO: watchdog reset instead to reset registers?
#ifdef APPCHECKSUM
if(!testForValidApplication())
asm volatile ("rjmp __vectors");
#endif
#ifdef TINY85MODE
// clear magic word from bottom of stack before jumping to the app
*(uint8_t*)(RAMEND) = 0x00;
*(uint8_t*)(RAMEND-1) = 0x00;
// jump to application reset vector at end of flash
asm volatile ("rjmp __vectors - 4");
#else
/* We must go through a global function pointer variable instead of writing
* ((void (*)(void))0)();
* because the compiler optimizes a constant 0 to "rcall 0" which is not
* handled correctly by the assembler.
*/
nullVector();
#endif
}
static inline void tiny85FlashInit(void)
{
// check for erased first page (no bootloader interrupt vectors), add vectors if missing
if(pgm_read_word(RESET_VECTOR_OFFSET * 2) != 0xC000 + (BOOTLOADER_ADDRESS/2) - 1 ||
pgm_read_word(USBPLUS_VECTOR_OFFSET * 2) != 0xC000 + (BOOTLOADER_ADDRESS/2) - 1)
{
// TODO: actually need to erase here? how could we end up with missing vectors but application data higher up?
# if HAVE_CHIP_ERASE
eraseApplication();
# else
fillFlashWithVectors();
# endif
}
// TODO: necessary to reset CURRENT_ADDRESS?
CURRENT_ADDRESS = 0;
# ifdef APPCHECKSUM
checksum = 0;
# endif
}
static inline void tiny85FlashWrites(void)
{
#if HAVE_CHIP_ERASE
if(eraseRequested)
{
_delay_ms(2);
cli();
eraseApplication();
sei();
#ifdef APPCHECKSUM
checksum = 0;
#endif
eraseRequested = 0;
}
#endif
if(flashPageLoaded)
{
_delay_ms(2);
// write page to flash, interrupts will be disabled for several milliseconds
cli();
if(CURRENT_ADDRESS % SPM_PAGESIZE)
fillFlashWithVectors();
else
writeFlashPage();
sei();
flashPageLoaded = 0;
if(isLastPage)
{
// store number of bytes written so rest of flash can be filled later
writeSize = CURRENT_ADDRESS;
appWriteComplete = 1;
}
}
}
