@tekka
I can now program my board with serial line. It's work perfectly.
It's an issue with my serial converteur and an usb hub. The usb hub add a delay that is not compatible with the bootloader.
Sorry for the question.
Nico

With this bootloader, i can not upload scetch with serial or USB.
Where does i made a mistake?
Is there a configuration that is specific to the bootloader?
Thanks

Hello
I succed to program booloader but y can not add my sketch to arduino with serial or USB line.
Is is activated by default?
Thanks.