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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 361 | andfri | 1 | #include <avr/interrupt.h> |
| 2 | #include <avr/boot.h> |
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| 3 | #include <avr/pgmspace.h> |
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| 4 | #include <avr/wdt.h> |
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| 5 | #include <flash.h> |
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| 6 | |||
| 7 | static uint16_t flash_prev_addr; |
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| 8 | static uint8_t flash_buffer_dirty = 0; |
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| 9 | static uint8_t* flash_pagebuf; |
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| 10 | |||
| 11 | void flash_flush_buffer() { |
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| 12 | uint8_t sreg; |
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| 13 | uint16_t word; |
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| 14 | uint8_t i; |
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| 15 | uint16_t* buf = (uint16_t*)flash_pagebuf; // Access buffer on a word basis. |
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| 16 | |||
| 17 | if (!flash_buffer_dirty) return; // Nothing to flush. |
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| 18 | |||
| 19 | // Copy the sram buffer to the temporary page buffer. |
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| 20 | for (i = 0; i < SPM_PAGESIZE/2; i++) { |
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| 21 | word = buf[i]; |
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| 22 | boot_page_fill(i*2, word); // Absolute addressing is not neccessary. |
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| 23 | } |
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| 24 | |||
| 25 | // Disable interrupts. |
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| 26 | sreg = SREG; |
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| 27 | cli(); |
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| 28 | |||
| 29 | eeprom_busy_wait(); // Make sure any eeprom access has finished. |
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| 30 | |||
| 31 | boot_page_erase(flash_prev_addr); |
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| 32 | boot_spm_busy_wait(); // Wait until the memory is erased. |
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| 33 | |||
| 34 | boot_page_write(flash_prev_addr); // Store buffer in flash page. |
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| 35 | boot_spm_busy_wait(); // Wait until the memory is written. |
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| 36 | |||
| 37 | flash_buffer_dirty = 0; |
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| 38 | |||
| 39 | // Reenable RWW-section again so we can return to BIOS after flashing. |
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| 40 | boot_rww_enable (); |
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| 41 | |||
| 42 | // Re-enable interrupts (if they were ever enabled). |
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| 43 | SREG = sreg; |
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| 44 | } |
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| 45 | |||
| 46 | void flash_load_buffer(uint16_t addr) { |
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| 47 | uint8_t i; |
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| 48 | uint8_t byte; |
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| 49 | uint16_t page = (addr / SPM_PAGESIZE) * SPM_PAGESIZE; |
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| 50 | |||
| 51 | // Load current flash page contents into sram page buffer to implement |
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| 52 | // flash read-modify-writes with word granularity. |
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| 53 | for (i = 0; i < SPM_PAGESIZE; i++) { |
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| 54 | byte = pgm_read_byte(page + i); |
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| 55 | flash_pagebuf[i] = byte; |
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| 56 | } |
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| 57 | } |
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| 58 | |||
| 59 | void flash_write_word(uint16_t addr, uint16_t word) { |
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| 60 | uint16_t* buf = (uint16_t*)flash_pagebuf; // Access buffer on a word basis. |
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| 61 | |||
| 62 | // Check if page address has changed since last write |
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| 63 | if ((addr / SPM_PAGESIZE) != (flash_prev_addr / SPM_PAGESIZE)) { |
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| 64 | flash_flush_buffer(); // Flash buffer contents to previous page |
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| 65 | flash_load_buffer(addr); // Read new page contents into buffer |
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| 66 | } |
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| 67 | |||
| 68 | buf[(addr % SPM_PAGESIZE)/2] = word; |
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| 69 | flash_prev_addr = addr; |
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| 70 | flash_buffer_dirty = 1; |
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| 71 | } |
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| 72 | |||
| 73 | void flash_init(uint8_t* buf) { |
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| 74 | // 0xffff is never in any page that can be written on devices with <= 64K flash, |
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| 75 | // so the first flash_write_word will always trigger a buffer load. |
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| 76 | flash_prev_addr = 0xffff; |
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| 77 | flash_pagebuf = buf; |
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| 78 | flash_buffer_dirty = 0; |
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| 79 | } |
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| 80 | |||
| 81 | extern void __flash_code_start; // Start of .flash_code from ld-script |
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| 82 | |||
| 83 | void flash_copy_data(uint16_t src, uint16_t dst, uint16_t len) { |
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| 84 | uint16_t data; |
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| 85 | |||
| 86 | cli(); // From this point we're on our own |
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| 87 | |||
| 88 | len = (len | (SPM_PAGESIZE - 1)) + 3; // Round len up to a whole page + 2 |
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| 89 | |||
| 90 | while (len -= 2) { |
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| 91 | if (dst >= (uint16_t)&__flash_code_start) break; |
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| 92 | |||
| 93 | wdt_reset(); |
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| 94 | |||
| 95 | data = pgm_read_word(src); // Read source word |
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| 96 | boot_page_fill(dst, data); // Write word to destination |
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| 97 | |||
| 98 | if ((dst + 2) % SPM_PAGESIZE == 0) { // If we just wrote the last word of a page |
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| 99 | boot_page_erase(dst); |
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| 100 | boot_spm_busy_wait(); // Wait until the memory is erased. |
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| 101 | boot_page_write(dst); // Store buffer in flash page. |
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| 102 | boot_spm_busy_wait(); // Wait until the memory is written. |
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| 103 | boot_rww_enable(); |
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| 104 | } |
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| 105 | |||
| 106 | src += 2; |
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| 107 | dst += 2; |
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| 108 | } |
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| 109 | |||
| 110 | while (1); // Nothing more we can do, hopefully there is a watchdog active |
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| 111 | } |