F xxxx yyyy zz - Fill memory from hex xxxx to yyyy with
F xxxx yyyy zz - Fill memory from hex xxxx to yyyy with
a single value of zz over the full range. The Dump command
a single value of zz over the full range. The Dump command
can be used to confirm that the Fill completed as expected. A
can be used to confirm that the fill completed as expected. A
good way to zero out memory areas before writing machine data
good way to zero out memory areas before writing machine data
for debug purposes.
for debug purposes.
@ -165,12 +166,16 @@ loads will be echoed as well while this facility is ‘on’.
## Load Hex format file into memory
## Load Hex format file into memory
L - Load a Intel Hex format file via the terminal program.
L - Load a Intel Hex format file via the terminal program.
The load address is defined in the hex file of the
assembled code.
The terminal emulator program should be configured to
The terminal emulator program should be configured to
give a delay at the end of each line to allow the monitor
give a delay at the end of each line to allow the monitor
enough time to parse the line and move the data to memory.
enough time to parse the line and move the data to memory.
Keep in mind that this will be a transient unless the
Keep in mind that this will be a transient unless the
system support backed memory. Saving to memory drive is
not supported.
system support battery backed memory. Saving to memory drive
is not supported.
## Move memory
## Move memory
@ -189,10 +194,18 @@ Use clip leaded LEDs to confirm the data written.
## Program memory location
## Program memory location
P xxxx - Program memory location xxxx. This routine will
P xxxx - Program memory location xxxx. This routine will
allow you to program a hexadecimal value into memory starting
allow you to program a hexadecimal value 'into memory starting
at location xxxx. Press 'Enter' on a blank line to
at location xxxx. Press 'Enter' on a blank line to
return to the Monitor prompt.
return to the Monitor prompt.
The limitation around programming memory is that it must be
entered in hexadecimal. An alternative is to use the L command
to load a program that has been assembled to a hex file on the
remote computer.
An excellent online resource for looking up opcodes for entry
can be found here: (https://clrhome.org/table)
## Run program
## Run program
R xxxx [[yy] [zzzz]] - Run program at location xxxx. If optional
R xxxx [[yy] [zzzz]] - Run program at location xxxx. If optional
@ -290,4 +303,171 @@ Press Q at any time to bring up the option to Quit or Restart the game.
# Network Boot
# Network Boot
# ZModem Flash Update
# Xmodem Flash Updater
The ROMWBW Xmodem flash updater provides the capability to update ROMWBW from the boot loader using an x-modem file transfer. It offers similar capabilities to Will Sowerbutts FLASH4 utility except that the flashing process occurs during the file transfer.
These are the key differences between the two methods are:
Available from the boot loader | Well proven and tested
Xmodem transfer is integrated | Wider range of supported chips and hardware
Integrated checksum utilities | Wider range of supported platforms
Capability to copy a ROM image | Only reprograms sectors that have changed
More convenient one step process | Ability save and verify ROM images
No intermediate storage required | Progress display while flashing
. | Displays chip identification information
. | Faster file transfer
The major disadvantages of the Updater is that it is new and relatively untested. There is the risk that a failed transfer will result in a partially flashed and unbootable ROM. There are some limitations on serial transfer speeds.
The updater utility was initially intended to support the Retrobrew SBC-V2-005 platform using Atmel 39SF040 flash chips but has now been extended to be more generic in operation.
The Atmel 39SF040 chip is recommended as it can erase and write 4Kb sectors. Other chips require the whole chip to be erased.
## Usage
In most cases, completing a ROM update is a simple as:
1. Booting to the boot loader prompt
2. Selecting option X - Xmodem Flash Updater
3. Selecting option U - Update
4. Initiating an X-modem transfer of your ROM image on your console device
5. Selecting option R - Reboot
If your console device is not able to transfer a ROM image i.e. your console is a VDU then you will have to use the console options to identify which character-input/output device is to be used as the serial device for transfer.
When your console is the serial device used for the transfer, no progress information is displayed as this would disrupt the x-modem file transfer. If you use an alternate character-input/output devices as the serial device for the transfer then progress information will be displayed on the console device.
Due to different platform processor speeds, serials speeds and flow control capabilities the default console or serial device speed may need to be reduced for a successful transfer and flash to occur. The **Set Console Interface/Baud code** option at the Boot Loader can be used to change the speed if required. Additionally, the Updater has options to set to and revert from a recommended speed.
## Console Options
Option ( C ) - Set Console Device
Option ( S ) - Set Serial Device
By default the updater assumes that the current console is a serial device and that the ROM file to be flashed will also be transferred across this device, so the Console and Serial device are both the same.
Either device can be can be change to another character-input/output device but the updater will always expect to receive the x-modem transfer on the **Serial Device**
The advantage of transferring on a different device to the console is that progress information can be displayed during the transfer.
Option ( > ) - Set Recommended Baud Rate
Option ( < ) - Revert t Original Baud Rate
## Programming options
Option ( U ) - Begin Update
The will begin the update process. The updater will expect to start receiving
an x-modem file on the serial device unit.
X-modem sends the file in packets of 128 bytes. The updater will cache 32
packets which is 1 flash sector and then write that sector to the
flash device.
If using separate console, bank and sector progress information will shown
```
BANK 00 s00 s01 s02 s03 s04 s05 s06 s06 s07
BANK 01 s00 s01 s02 s03 s04 s05 s06 s06 s07
BANK 02 s00 s01 s02 s03 s04 s05 s06 s06 s07 etc
```
The x-modem file transfer protocol does not provide any filename or size
information for the transfer so the updater does not perform any checks
on the file suitability.
The updater expects the file size to be a multiple of 4 kilobytes and
will write all data received to the flash device. A system update
file (128kb .img) or complete ROM can be received and written (512kb or
1024kb .rom)
If the update fails it is recommended that you retry before rebooting or
exiting to the Boot loader as your machine may not be bootable.
Option ( D ) - Duplicate flash #1 to flash #2
This option will make a copy of flash #1 ont flash #2. The purpose of this is to enable
making a backup copy of the current flash. Intended for systems using 2x512Kb Flash devices.
Option ( V ) - Toggle Write Verify
By default each flash sector will be verified after being written. Slight
performance improvements can be gained if turned off and could be used if
you are experiencing reliable transfers and flashing.
## Exit options
Option ( R ) - Reboot
Execute a cold reboot. This should be done after a successful update. If
you perform a cold reboot after a failed update then it is likely that
your system will be unusable and removing and reprogramming the flash
will be required.
Option (Q) - Quit to boot loader. The SBC Boot Loader is reloaded from ROM and
executed. After a successful update a Reboot should be performed. However,
in the case of a failed update this option could be used to attempt to
load CP/M and perform the normal x-modem / flash process to recover.
## CRC Utility options
Option (1) and (2) - Calculate and display CRC32 of 1st or 2nd 512k ROM.
Option (3) - Calculate and display CRC32 of a 1024k (2x512Kb) ROM.
Can be used to verify if a ROM image has been transferred and flashed correctly. Refer to the Teraterm section below for details on configuring the automatic display of a files CRC after it has been transferred.
In Windows, right clicking on a file should also give you a contect menu option CRC SHA which will allow you to select a CRC32 calculation to be done on the selected file.
## Teraterm macro configuration
Macros are a useful tool for automatic common tasks. There are a number of instances where using macros to facilitate the update process could be worthwhile if you are:
* Following the ROMWBW development builds.
* Doing lots of configuration changes.
* Doing development on ROMWBW drivers
Macros can be used to automate sending ROM updates or images and for my own purposed I have set up a separate macro for transferring each of the standard build ROM, my own custom configuration ROM and update ROM.
An example macro file to send an *.upd file, using checksum mode and display the crc32 value of the transmitted file:
As identified in the introduction, there are limitations on serial speed depending on processor speed and flow control settings. Listed below are some of the results identified during testing.
Platform / Configuration | Processor Speed | Maximum Serial Speed
b1ackmai1er
4 years ago