RedBoot supports the serial port labelled P2 on the board. The default serial port settings are 57600,8,N,1. RedBoot also supports flash management on the Excalibur.
The following RedBoot configurations are supported:
| Configuration | Mode | Description | File |
|---|---|---|---|
| ROMRAM | [ROMRAM] | RedBoot running from RAM, but contained in the board's flash boot sector. | redboot_ROMRAM.ecm |
| RAM | [RAM] | RedBoot running from RAM with RedBoot in the flash boot sector. | redboot_RAM.ecm |
| REDBOOT | [ROMRAM] | RedBoot running from top of RAM, but contained in the board's flash boot sector. | redboot_REDBOOT.ecm |
NOTE: RedBoot is currently hardwired to use a 128MB SDRAM SIMM module.
A Windows utility (exc_flash_programmer.exe) is used to program flash using the ByteBlasterMV JTAG unit. See board documentation for details on in situ flash programming.
For ethernet to work (under Linux) the following jumper settings should be used on a REV 2 board:
SW2-9 : OFF
U179 : 2-3
JP14-18 : OPEN
JP40-41 : 2-3
JP51-55 : 2-3
The ROMRAM and REDBOOT configurations supported on this platform differ only in the memory layout (ROMRAM configuration runs RedBoot from 0x00008000 while REDBOOT configuration runs RedBoot from 0x07f80000). The REDBOOT configuration allows applications to be loaded and run from address 0x00008000.
The exec command which allows the loading and execution of Linux kernels, is supported for this board (see the Section called Executing Programs from RedBoot in Chapter 2). The exec parameters used for the Excalibur are:
Location Linux kernel was loaded to
Length of kernel
Parameters passed to kernel
'initrd' ramdisk location
Length of initrd ramdisk
The parameters for kernel image base and size are automatically set after a load operation. So one way of starting the kernel would be:
RedBoot> load -r -b 0x100000 zImage Raw file loaded 0x00100000-0x001a3d6c RedBoot> exec -c "console=ttyUA0,57600" Using base address 0x00100000 and length 0x000a3d6c Uncompressing Linux..... |
RedBoot> exec -b 0x40400000 -l 0xc0000 -c "console=ttyUA0,57600" Uncompressing Linux..... |
The MMU page tables are located at 0x4000.
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 - 0x07ffffff SDRAM 0x08000000 - 0x0805ffff On-chip SRAM 0x40000000 - 0x40ffffff Flash 0x7fffc000 - 0x7fffffff I/O registers 0x80000000 - 0x8001ffff PLD Virtual Address Range C B Description ----------------------- - - ---------------------------------- 0x00000000 - 0x07ffffff Y Y SDRAM 0x08000000 - 0x0805ffff Y Y On-chip SRAM 0x40000000 - 0x403fffff N Y Flash 0x7fffc000 - 0x7fffffff N N I/O registers 0x80000000 - 0x8001ffff N N PLD |
These shell variables provide the platform-specific information needed for building RedBoot according to the procedure described in Chapter 3:
export TARGET=excalibur_arm9 export ARCH_DIR=arm export PLATFORM_DIR=arm9/excalibur |
The names of configuration files are listed above with the description of the associated modes.