RedBoot support is available for the EB40, EB40A, EB42 and EB55 boards. By default all these boards are shipped with only 256Kbytes of RAM. To minimize the amount of RAM used by RedBoot, only very basic flash management is provided, comprising of just the fis erase and fis write commands.
RedBoot supports both serial ports. On all AT91 evaluation boards, serial port A requires a straight through cable to connect with a PC, whereas serial port B requires a null modem cable. If you fail to be able to connect to Angel in the instructions below when installing RedBoot, be sure to verify you are using the appropriate cable for the serial port. The default serial port settings for RedBoot are 38400,8,N,1.
The following RedBoot configurations are supported:
RedBoot installation is essentially the same for all boards, however the details differ slightly. Please make sure you follow the directions from the correct section below. Any errors could result in an unusable board.
This development board comes with ARM's debug tool, Angel, installed in flash. At this time, Angel will not be replaced. Rather, RedBoot will be placed in the alternate half of flash. Switch SW1 is used to select which monitor to boot. Once RedBoot is installed, selecting SW1 to lower mem will choose Angel, whereas selecting SW1 to upper mem will choose RedBoot.
Set SW1 to lower mem and connect serial port A to a host computer. Using GDB from the host and Angel on the board, download and run the RAM mode image of RedBoot to the board.
arm-elf-gdb redboot_RAM.elf (gdb) tar rdi s=/dev/ttyS0 Angel Debug Monitor (serial) 1.04 (Advanced RISC Machines SDT 2.5) for AT91EB40 (2.00) Angel Debug Monitor rebuilt on Apr 07 2000 at 12:40:31 Serial Rate: 9600 Connected to ARM RDI target. (gdb) set $cpsr=0xd3 (gdb) load Loading section .rom_vectors, size 0x40 lma 0x2020000 Loading section .text, size 0x7fd8 lma 0x2020040 Loading section .rodata, size 0x15a0 lma 0x2028018 Loading section .data, size 0x2e4 lma 0x20295b8 Start address 0x2020040 , load size 39068 Transfer rate: 6250 bits/sec, 500 bytes/write. (gdb) cont Continuing. |
RedBoot> version RedBoot(tm) bootstrap and debug environment [RAM] Non-certified release, version UNKNOWN - built 14:09:27, Jul 20 2001 Platform: Atmel AT91/EB40 (ARM7TDMI) Copyright (C) 2000, 2001, Red Hat, Inc. RAM: 0x02000000-0x02080000, 0x020116d8-0x0207fd00 available FLASH: 0x01010000 - 0x01020000, 256 blocks of 0x00000100 bytes each. RedBoot> |
RedBoot> load -m ymodem -b %{FREEMEMLO} |
RedBoot> fi wr -f 0x01010000 -b %{FREEMEMLO} -l 0xe100 |
These development boards come with ARM's debug tool, Angel, installed in flash. At this time, Angel will not be replaced. Rather, RedBoot will be placed in the alternate half of flash. Jumper JP1 is used to select which monitor to boot. Once RedBoot is installed, setting JP1 to STD will choose Angel, whereas setting JP1 to USER will choose RedBoot.
Set JP1 to STD and connect serial port A to a host computer. Using GDB from the host and Angel on the board, download the RAM mode image of RedBoot to the board, and start it using the 'cont' command.
arm-elf-gdb redboot_RAM.elf (gdb) tar rdi s=/dev/ttyS0 Angel Debug Monitor (serial) 1.04 (Advanced RISC Machines SDT 2.5) for AT91EB55 (2.20) Angel Debug Monitor rebuilt on Feb 03 2002 at 16:10:20 Serial Rate: 9600 Connected to ARM RDI target. (gdb) set $cpsr=0xd3 (gdb) load Loading section .rom_vectors, size 0x40 lma 0x2008000 Loading section .text, size 0xb0b8 lma 0x2008040 Loading section .rodata, size 0x1c27 lma 0x20130f8 Loading section .data, size 0x5f0 lma 0x2014d20 Start address 0x2008040, load size 54031 Transfer rate: 6264 bits/sec, 500 bytes/write. (gdb) cont Continuing. |
RedBoot> version
RedBoot(tm) bootstrap and debug environment [RAM]
Non-certified release, version UNKNOWN - built 16:58:52, May 7 2003
Platform: Atmel AT91/EB55 (ARM7TDMI)
Copyright (C) 2000, 2001, 2002, Red Hat, Inc.
RAM: 0x02000000-0x02040000, 0x020068a8-0x0203f000 available
FLASH: 0x01010000 - 0x01200000, 31 blocks of 0x00010000 bytes each.
RedBoot> |
RedBoot> load -m ymodem -b %{FREEMEMLO} |
RedBoot> fi wr -f 0x01100000 -b %{FREEMEMLO} -l 0x10000 |
This processor has no MMU, so the only memory map is for physical addresses.
The memory layout of the EB40 is as follows:
Physical Address Range Description ----------------------- ---------------------------------- 0x00000000 - 0x00000fff On-chip SRAM 0x01000000 - 0x0101ffff Flash 0x02000000 - 0x0207ffff RAM 0xffe00000 - 0xffffffff I/O registers |
The memory layout of the EB40A is as follows:
Physical Address Range Description ----------------------- ---------------------------------- 0x00000000 - 0x0003ffff On-chip SRAM 0x01000000 - 0x011fffff Flash 0x02000000 - 0x02ffffff External SRAM (optional) 0xffe00000 - 0xffffffff I/O registers |
The memory layout of the EB42 and EB55 is as follows:
Physical Address Range Description ----------------------- ---------------------------------- 0x00000000 - 0x00001fff On-chip SRAM 0x01000000 - 0x011fffff Flash 0x02000000 - 0x0203ffff RAM 0xffe00000 - 0xffffffff I/O registers |
These shell variables provide the platform-specific information needed for building RedBoot according to the procedure described in Chapter 3:
export ARCH_DIR=arm export TARGET=eb40 export PLATFORM_DIR=at91/eb40 export TARGET=eb40a export PLATFORM_DIR=at91/eb40a export TARGET=eb42 export PLATFORM_DIR=at91/eb42 export TARGET=eb55 export PLATFORM_DIR=at91/eb55 |
The names of configuration files are listed above with the description of the associated modes.
When reprogramming RedBoot using RedBoot itself, you should load a RedBoot RAM image as normal, and load the new ROM image into RAM. However before programming the new image into Flash you must switch SW1 to lower mem (EB40) or set JP1 to STD (EB40A, EB42, EB55) before writing to Flash.
| Warning! |
Failure to set SW1 to lower mem (EB40) or JP1 to STD (EB40A, EB42, EB55) will cause the installation of RedBoot to overwrite Angel, thus making the board unbootable. Only hardware JTAG can restore the board once in this state. |