Sys/BIOS or StarterWare one ARM

Hi,

In my project we need to get boot time of 3sec from power up.

So it seems Linux is off the table, we reached an image (uImage) of size 2.5MB including initramfs and the boot time stands on 9.7 sec from power up.

Loading from NAND16 (UBL,Uboot,Kernel,initramfs).

 If i need only basic access to GPIO/I2C/SPI interfaces and a communication channel between the arm and the DSP. 

Is SYS/BIOS on ARM is enough ? and did somebody already done it ? and can say how difficult it may be ?

Is  StarterWare can be a good solution ?

Thanks

Hen