diff options
| author | tmk <hasu@tmk-kbd.com> | 2015-05-13 15:01:49 +0900 |
|---|---|---|
| committer | tmk <hasu@tmk-kbd.com> | 2015-05-13 15:01:49 +0900 |
| commit | 192024124b65fb65a65b44eef0bbc308c5971cea (patch) | |
| tree | 46193b2eb18837f2d2a5bc9f02a0d281f3d35e22 /tmk_core | |
| parent | 6057e915b53728f7b9d421b604c7c4654ca58743 (diff) | |
Add description of AVR bootloader and boot section
Diffstat (limited to 'tmk_core')
| -rw-r--r-- | tmk_core/common/avr/bootloader.c | 49 |
1 files changed, 43 insertions, 6 deletions
diff --git a/tmk_core/common/avr/bootloader.c b/tmk_core/common/avr/bootloader.c index cda295b181..7c744e8c79 100644 --- a/tmk_core/common/avr/bootloader.c +++ b/tmk_core/common/avr/bootloader.c @@ -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. |