BootROM
RM0082
826/844
Doc ID 018672 Rev 1
38 BootROM
BootROM is a small piece of code that starts its execution just after the SoC exits from
reset.
The following are the features supported by SPEAr300 BootROM:
●
Boot from NOR serial Flash
●
Boot from NAND Flash
●
Boot from NOR parallel Flash
●
Boot / Upgrade from USB
●
Boot from UART
●
Boot from Ethernet
First three are the normal ways of booting the software and requires to have a second-level
boot software (Xloader) in NOR/NAND Flash.
Last three types (USB/UART/Ethernet) are meant to boot without Flash memories. USB
boot is used to upgrade 1
st
to 3
rd
level boot in Flash memories.
.
38.1 Boot
Stages
describes boot stages on SPEAr SOC in more details. There are 4 stages of
booting:-
●
Boot stage 1 (BootROM)
●
Boot stage 2 (Xloader)
●
Boot stage 3 (Bootloader e.g. U-Boot)
●
OS
Table 743.
Booting types
Booting using Flash
memories
Booting without using Flash
memories
Upgrading the Flash
memories
Serial NOR
UART
USB
Parallel NOR
Ethernet
Parallel NAND