RedBoot supports both front facing serial ports and the built in ethernet port for communication and downloads. The default serial port settings are 38400,8,N,1. RedBoot runs from and supports flash management for the system flash region.
The following RedBoot configurations are supported:
RedBoot is installed using the code download facility built into the Malta board. See the Malta User manual for details, and also the Malta download format in the Section called Malta download format.
Here are quick start instructions for downloading the prebuilt RedBoot image.
Locate the prebuilt files in the bin directory: deleteall.fl and redboot_ROM.fl.
Make sure switch S5-1 is ON. Reset the board and verify that the LED display reads Flash DL.
Make sure your parallel port is connected to the 1284 port Of the Atlas board.
Send the deleteall.fl file to the parallel port to erase previous images:
$ cat deleteall.fl >/dev/lp0
Send the RedBoot image to the board:
$ cat redboot_ROM.fl >/dev/lp0
Change switch S5-1 to OFF and reset the board. The LED display should read RedBoot.
Run the RedBoot fis init and fconfig commands to initialize the flash. See the Section called Flash Image System (FIS) in Chapter 2 and the Section called Persistent State Flash-based Configuration and Control in Chapter 2 for details.
In order to download RedBoot to the Malta board, it must be converted to the Malta download format.
The Atlas/Malta Developer's Kit CD contains an srecconv.pl utility which requires Perl. This utility is part of the yamon/yamon-src-02.00.tar.gz tarball on the Dev Kit CD. The path in the expanded tarball is yamon/bin/tools. To use srecconv to convert the S-record file:
$ cp redboot_ROM.srec redboot_ROM.rec $ srecconv.pl -ES L -A 29 redboot_ROM
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 uses an interrupt vector table which is located at address 0x80000200. Entries in this table are pointers to functions with this protoype:
int irq_handler( unsigned vector, unsigned data )
#define CYGNUM_HAL_INTERRUPT_SOUTH_BRIDGE_INTR 0 #define CYGNUM_HAL_INTERRUPT_SOUTH_BRIDGE_SMI 1 #define CYGNUM_HAL_INTERRUPT_CBUS_UART 2 #define CYGNUM_HAL_INTERRUPT_COREHI 3 #define CYGNUM_HAL_INTERRUPT_CORELO 4 #define CYGNUM_HAL_INTERRUPT_COMPARE 5 #define CYGNUM_HAL_INTERRUPT_TIMER 6 #define CYGNUM_HAL_INTERRUPT_KEYBOARD 7 #define CYGNUM_HAL_INTERRUPT_CASCADE 8 #define CYGNUM_HAL_INTERRUPT_TTY1 9 #define CYGNUM_HAL_INTERRUPT_TTY0 10 #define CYGNUM_HAL_INTERRUPT_11 11 #define CYGNUM_HAL_INTERRUPT_FLOPPY 12 #define CYGNUM_HAL_INTERRUPT_PARALLEL 13 #define CYGNUM_HAL_INTERRUPT_REAL_TIME_CLOCK 14 #define CYGNUM_HAL_INTERRUPT_I2C 15 #define CYGNUM_HAL_INTERRUPT_PCI_AB 16 #define CYGNUM_HAL_INTERRUPT_PCI_CD 17 #define CYGNUM_HAL_INTERRUPT_MOUSE 18 #define CYGNUM_HAL_INTERRUPT_19 19 #define CYGNUM_HAL_INTERRUPT_IDE_PRIMARY 20 #define CYGNUM_HAL_INTERRUPT_IDE_SECONDARY 21
An application may create a normal C function with the above prototype to be an ISR. Just poke its address into the table at the correct index and enable the interrupt at its source. The return value of the ISR is ignored by RedBoot.
Memory Maps RedBoot sets up the following memory map on the Malta board.
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 C B Description ----------------------- - - ----------- 0x80000000 - 0x81ffffff Y Y SDRAM 0x9e000000 - 0x9e3fffff Y N System flash (cached) 0x9fc00000 - 0x9fffffff Y N System flash (mirrored) 0xa8000000 - 0xb7ffffff N N PCI Memory Space 0xb4000000 - 0xb40fffff N N Galileo System Controller 0xb8000000 - 0xb80fffff N N Southbridge / ISA 0xb8100000 - 0xbbdfffff N N PCI I/O Space 0xbe000000 - 0xbe3fffff N N System flash (noncached) 0xbf000000 - 0xbfffffff N N Board logic FPGA
These shell variables provide the platform-specific information needed for building RedBoot according to the procedure described in Chapter 3:
export TARGET=malta_mips32_4kc export ARCH_DIR=mips export PLATFORM_DIR=malta
The names of configuration files are listed above with the description of the associated modes.