diff options
Diffstat (limited to 'FAQ.md')
| -rw-r--r-- | FAQ.md | 51 |
1 files changed, 40 insertions, 11 deletions
@@ -106,21 +106,50 @@ http://arduino.cc/en/uploads/Main/arduino-micro-schematic.pdf ## Bootloader jump doesn't work
-Properly configure boot section size in Makefile. With wrong section size bootloader won't probably start with **Magic command** and **Boot Magic**.
-- https://github.com/tmk/tmk_keyboard#magic-commands
-- https://github.com/tmk/tmk_keyboard#bootloader
-
+Properly configure bootloader size in Makefile. With wrong section size bootloader won't probably start with **Magic command** and **Boot Magic**.
```
-# Boot Section Size in *bytes*
-# Teensy halfKay 512
-# Teensy++ halfKay 1024
-# Atmel DFU loader 4096 (TMK Alt Controller)
-# LUFA bootloader 4096
-# USBaspLoader 2048
+# 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
OPT_DEFS += -DBOOTLOADER_SIZE=4096
```
+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**.
+
+AVR Boot section is located at end of Flash memory like the followings.
+```
+byte Atmel/LUFA(ATMega32u4) byte Atmel(AT90SUB1286)
+0x0000 +---------------+ 0x00000 +---------------+
+ | | | |
+ | | | |
+ | Application | | Application |
+ | | | |
+ = = = =
+ | | 32KB-4KB | | 128KB-8KB
+0x6000 +---------------+ 0x1FC00 +---------------+
+ | Bootloader | 4KB | Bootloader | 8KB
+0x7FFF +---------------+ 0x1FFFF +---------------+
+
+
+byte Teensy(ATMega32u4) byte Teensy++(AT90SUB1286)
+0x0000 +---------------+ 0x00000 +---------------+
+ | | | |
+ | | | |
+ | Application | | Application |
+ | | | |
+ = = = =
+ | | 32KB-512B | | 128KB-1KB
+0x7E00 +---------------+ 0x1FC00 +---------------+
+ | Bootloader | 512B | Bootloader | 1KB
+0x7FFF +---------------+ 0x1FFFF +---------------+
+```
-And see this discussion.
+And see this discussion for further reference.
https://github.com/tmk/tmk_keyboard/issues/179
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