Bios R4i, where is it ?

Hi everybody !I'm looking for the bios for N4i,
I used the Bios for Nintendo Ds' Xl with the Bios for N5 but it wached " NO Menu" on the screen, perhaps is not a good system.
So, i think is better find the N4i's system.
How just i do it ?
Where may i find it ?ThanksThanksThanksThanksThanksThanksThanksThanks