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Add description of AVR bootloader and boot section

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tmk 2015-05-13 15:01:49 +09:00
parent 6057e915b5
commit 192024124b
1 changed files with 43 additions and 6 deletions
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49
tmk_core/common/avr/bootloader.c
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@ -11,12 +11,49 @@
#endif
/* Boot Section Size in *BYTEs*
* Teensy halfKay 512
* Teensy++ halfKay 1024
* Atmel DFU loader 4096
* LUFA bootloader 4096
* USBaspLoader 2048
/* Bootloader Size in *bytes*
*
* AVR Boot section size are defined by setting BOOTSZ fuse in fact. Consult with your MCU datasheet.
* Note that 'Word'(2 bytes) size and address are used in datasheet while TMK uses 'Byte'.
*
*
* Size of Bootloaders in bytes:
* Atmel DFU loader(ATmega32U4) 4096
* Atmel DFU loader(AT90USB128) 8192
* LUFA bootloader(ATmega32U4) 4096
* Arduino Caterina(ATmega32U4) 4096
* USBaspLoader(ATmega***) 2048
* Teensy halfKay(ATmega32U4) 512
* Teensy++ halfKay(AT90USB128) 1024
*
*
* AVR Boot section is located at the end of Flash memory like the followings.
*
*
* byte Atmel/LUFA(ATMega32u4) byte Atmel(AT90SUB128)
* 0x0000 +---------------+ 0x00000 +---------------+
* | | | |
* | | | |
* | Application | | Application |
* | | | |
* = = = =
* | | 32KB-4KB | | 128KB-8KB
* 0x6000 +---------------+ 0x1FC00 +---------------+
* | Bootloader | 4KB | Bootloader | 8KB
* 0x7FFF +---------------+ 0x1FFFF +---------------+
*
*
* byte Teensy(ATMega32u4) byte Teensy++(AT90SUB128)
* 0x0000 +---------------+ 0x00000 +---------------+
* | | | |
* | | | |
* | Application | | Application |
* | | | |
* = = = =
* | | 32KB-512B | | 128KB-1KB
* 0x7E00 +---------------+ 0x1FC00 +---------------+
* | Bootloader | 512B | Bootloader | 1KB
* 0x7FFF +---------------+ 0x1FFFF +---------------+
*/
#ifndef BOOTLOADER_SIZE
#warning To use bootloader_jump() you need to define BOOTLOADER_SIZE in config.h.