RedBoot uses the front facing serial port. The default serial port settings are 38400,8,N,1. RedBoot also supports ethernet. Management of onboard flash is also supported.
The following RedBoot configurations are supported:
The exec command which allows the loading and execution of Linux kernels, is supported for this architecture (see the Section called Executing Programs from RedBoot in Chapter 2). The exec parameters used for MIPS boards are:
Location to store command line and environment passed to kernel
Wait time in seconds before starting kernel
Parameters passed to kernel
Kernel entry point, defaulting to the entry point of the last image loaded
Linux kernels on MIPS platforms expect the entry point to be called with arguments in the registers equivalent to a C call with prototype:
void Linux(int argc, char **argv, char **envp);
RedBoot will place the appropriate data at the offset specified by the
-b parameter, or by default at address 0x80080000, and will set the
arguments accordingly when calling into the kernel.
The default entry point, if no image with explicit entry point has been loaded and none is specified, is 0x80000750.
RedBoot sets up the following memory map on the Ocelot board.
Note that these addresses are accessed through kseg0/1 and thus translate to the actual address range 0x80000000-0xbfffffff, depending on the need for caching/non-caching access to the bus.
NOTE: The virtual memory maps in this section use a C and B column to indicate whether or not the region is cached (C) or buffered (B).
Physical Address Range Description ----------------------- ----------- 0x00000000 - 0x0fffffff SDRAM 0x10000000 - 0x10ffffff PCI I/O space 0x12000000 - 0x13ffffff PCI Memory space 0x14000000 - 0x1400ffff Galileo system controller 0x1c000000 - 0x1c0000ff PLD (board logic) 0x1fc00000 - 0x1fc7ffff flash
These shell variables provide the platform-specific information needed for building RedBoot according to the procedure described in Chapter 3:
export TARGET=ocelot export ARCH_DIR=mips export PLATFORM_DIR=rm7000/ocelot
The names of configuration files are listed above with the description of the associated modes.