Hitachi Solution Engine 77X9 (SE77X9)

Overview

This description covers the MS7729SE01 and MS7709SSE0101 variants. See the Section called Hitachi Solution Engine 7709 (SE77X9) for instructions for the MS7709SE01 variant.

RedBoot uses the COM1 and COM2 serial ports. The default serial port settings are 38400,8,N,1. Ethernet is also supported using the 10-base T connector.

Management of onboard flash is also supported. Two basic RedBoot configurations are supported:

Initial Installation Method

The Solution Engine ships with the Hitachi boot monitor in EPROM which allows for initial programming of RedBoot:

  1. Set switches SW4-3 and SW4-4 to ON [boot from EPROM]

  2. Connect a serial cable to COM2 and power up the board.

  3. After the boot monitor banner, invoke the flash download/program command:
    Ready >fl

  4. The monitor should now ask for input:
    Flash ROM data copy to RAM
    Please Send A S-format Record
    At this point copy the RedBoot ROM SREC file to the serial port:
    $ cat redboot_ROM.eprom.srec > /dev/ttyS0
    Eventually you should see something like
    Start Addrs = A1000000
    End Addrs = A1xxxxxx
    Transfer complete
    from the monitor.

  5. Set switch SW4-3 to OFF [boot from flash] and reboot the board. You should now see the RedBoot banner.

Flash management

Special RedBoot Commands

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 SE77x9 are:

-b <addr>

Parameter block address. This is normally the first page of the kernel image and defaults to 0x8c101000

-i <addr>

Start address of initrd image

-j <size>

Size of initrd image

-c "args"

Kernel arguments string

-m <flags>

Mount rdonly flags. If set to a non-zero value the root partition will be mounted read-only.

-f <flags>

RAM disk flags. Should normally be 0x4000

-r <device number>

Root device specification. /dev/ram is 0x0101

-l <type>

Loader type

Finally the kernel entry address can be specified as an optional argument. The default is 0x8c102000

On the SE77x9, Linux expects to be loaded at address 0x8c101000 with the entry point at 0x8c102000. This is configurable in the kernel using the CONFIG_MEMORY_START option.

Memory Maps

RedBoot sets up the following memory map on the SE77x9 board.
Physical Address Range  Description
----------------------- -----------
0x80000000 - 0x803fffff Flash (MBM29LV160)
0x81000000 - 0x813fffff EPROM (M27C800)
0x8c000000 - 0x8dffffff SDRAM
0xb0000000 - 0xb03fffff Ethernet (DP83902A)
0xb0400000 - 0xb07fffff SuperIO (FDC37C935A)
0xb0800000 - 0xb0bfffff Switches
0xb0c00000 - 0xbfffffff LEDs
0xb1800000 - 0xb1bfffff PCMCIA (MaruBun)

Ethernet Driver

The ethernet driver uses a hardwired ESA which can, at present, only be changed in CDL.

Resource Usage

The flash based RedBoot image occupies flash addresses 0x80000000 - 0x8001ffff. RedBoot also reserves RAM (0x8c000000 - 0x8c01ffff) for RedBoot runtime uses. RAM based RedBoot configurations are designed to run from RAM at physical addresses 0x8c020000 - 0x8c07ffff. RAM physical addresses from 0x8c080000 to the end of RAM are available for general use, such as a temporary scratchpad for downloaded images, before they are written to flash.

Rebuilding RedBoot

The instructions in Chapter 3 should be followed. The values for TARGET, ARCH_DIR and PLATFORM_DIR on this platform are “se77x9”, “sh” and “se77x9” respectively. Note that the configuration export files supplied in the hal/sh/se77x9/VERSION/misc directory in the RedBoot source tree should be used.