Zeal Bootloader v1.3.1 (May 2024)

Release v1.3.1 for Zeal 8-bit Bootloader.

This release bring the following modifications:

• Fix a bug in the hardware tester that reported a wrong RAM size. The root cause was the unpredictable pattern in RAM that needed to be detected by the tester

DISCLAIMER: It is always risky to update your bootloader. Please read the notes and remarks from the release v1.3.0

Zeal Bootloader v1.3.0 (April 2024)

Release v1.3.0 for Zeal 8-bit Bootloader.

First release that brings support for both the PS/2 keyboard and the Zeal 8-bit Video Card. Former versions of the bootloader only used UART for communication.

New features

Here is the the list of the new features:

• Add a command to flash the Zeal 8-bit Video Board firmware directly from the menu
• Zeal 8-bit Video Board is now the default standard output
• The PS/2 keyboard is now the default standard input
• Possibility to enter bootloader menu after pressing ESC key on the PS/2 keyboard, else autobooting is performed if ESC key is not detected
• The logo and version can be shown on the video output
• Add a possibility to wait for a key press after every operation that finishes
• A configuration file, named include/config.asm, has been created to modify the configuration of the system, which includes:
  • Choosing between UART or video/keyboard for the output and input (default video/keyboard)
  • Show Zeal logo (default true). Not showing the logo will save some RAM and a bit of speed.
  • Enable the hardware tester (default true)
  • Wait for a key input after finishing any operation from the menu (default true)
  • Autoboot delay, which is now 3 seconds (instead of the former 5)

Remarks

A few things to note now that the video board is supported.

• After updating the bootloader to this release, the UART will only be used in the situations below:
  • Transferring file to flash the NOR Flash or update the video board firmware
  • In case the video board is in Recovery Mode, the bootloader will use UART to ask the user for a new binary to flash to the video board.
• There is no way to switch to UART for the standard output apart from (recompiling and) reflashing the bootlaoder with the proper configuration.
• Some VGA screen may take some time to render the first frames when the board is powered up, but it is still possible to press the ESC key to enter the menu, even nothing is visible on screen yet. Pressing the ESC key multiple times is possible (safe) and will not result in a corruption or any undefined behavior.

Upgrading the bootloader from the bootloader itself is always risky

As such, if your Zeal 8-bit Computer is still using UART and doesn't have the video board, there is no reason to update to this release since the features added are solely related to that new board.

This new bootloader release can be flashed via the former versions or using an external programmer such as the TL866 for example.

Zeal Bootloader v1.2.0 (February 2023)

This release bring the following modifications:

• Add a new command to format the Zeal 8-bit Computer's I2C EEPROM. The EEPROM will be formatted to use ZealFS. The possible memory sizes are 16KB, 32KB and 64KB.
• The hardware tester now does a backup of the EEPROM before testing its size
• Fix a bug in the I2C driver that affected UART lines during a transmision

Zeal Bootloader v1.1.0 (January 2023)

This release bring the following modifications:

• Fix a bug in the hardware tester that resulted in NOR flash corruption
• Make the flasher perform a software reset after flashing/updating the bootloader

Zeal Bootloader v1.0.0 (December 2022)

First public release. This version is shipped with the first batch of Zeal 8-bit Computer.

Features list

• Communication over UART. There is currently no support for the video board.
• 5 seconds auto-boot on startup.
• Up to 9 operating systems or programs can be set up to boot from the menu. These entries are saved at offset 0x2000 in flash.
• New entries can be added as bootable systems.
• Entries can be deleted directly from the bootloader.
• Buffered changes. All entries changes are buffered, they can then be discarded or flushed (saved to ROM).
• Program can be sent through UART, and booted directly.
• Baudrate can be changed for the current bootloader session.
• Test Zeal 8-bit Computer hardware components.

The raw size of the code of this version is 5KB. The binary file is bigger in reality as it includes a padding so that the system table (saving all the system entries) is at offset 0x2000 (8194) of the file.