Alternate Boot Data Structure

MOTLoad Firmware

 

 

6.7.4Alternate Boot Data Structure

The globalData field of the alternate boot data structure points to an area of RAM which was initialized to zeroes by the boot loader. This area of RAM is not cleared by the boot loader after execution of a POST image, or other alternate boot image, is executed. It is intended to provide a user a mechanism to pass POST image results to subsequent boot images.

The boot loader performs no other initialization of the board than that specified prior to the transfer of control to either a POST, USER, or Alternate MOTLoad image. Alternate boot images need to initialize the board to whatever state the image may further require for its execution.

POST images are expected, but not required, to return to the boot loader. Upon return, the boot loader proceeds with the scan for an executable alternate boot image. POST images that return control to the boot loader must ensure that upon return, the state of the board is consistent with the state that the board was in at POST entry. USER images should not return control to the boot loader.

6.7.5Alternate Boot Images and Safe Start

Some later versions of MOTLoad support alternate boot images and a safe start recovery procedure. If safe start is available on the MVME7100, alternate boot images are supported. With alternate boot image support, the boot loader code in the boot block examines the upper 8 MB of the flash bank for alternate boot images. If an image is found, control is passed to the image.

6.7.6Boot Image Firmware Scan

The scan is performed by examining each 1 MB boundary for a defined set of flags that identify the image as being POST, USER, or Alternate MOTLoad. POST is a user-developed Power On Self Test that would perform a set of diagnostics and then return to the boot loader image.

USER would be a boot image, such as the VxWorks bootrom, which would perform board initialization. A bootable VxWorks kernel would also be a USER image. Boot images are not restricted to being 1 MB or less in size; however, they must begin on a 1 MB boundary within the 8 MB of the scanned flash bank. The flash bank structure is shown below:

Address

Usage

 

 

0xFFF00000 to 0xFFFFFFFF

Boot block. Recovery code.

 

 

0xFFE00000 to 0XFFFFFFFF

Backup MOTLoad image

 

 

0xFFD00000 to 0xFFDFFFFF

First possible alternate image

 

 

0xFFC00000 to 0xFFCFFFFF

Second possible alternate image

 

 

....

Alternate boot images

 

 

0xFF899999 to 0xFF8FFFFF

Bottom of flash (flash size varies per product)

 

 

The scan is performed downwards beginning at the location of the first possible alternate image and searches first for POST, then USER, and finally Alternate MOTLoad images. In the case of multiple images of the same type, control is passed to the first image encountered in the scan.

MVME7100 Single Board Computer Installation and Use (6806800E08A)

97

Page 97
Image 97
Emerson MVME7100 manual Alternate Boot Data Structure, Alternate Boot Images and Safe Start, Boot Image Firmware Scan

MVME7100 specifications

The Emerson MVME7100 is a powerful and versatile embedded computing platform designed for demanding applications in various fields, including telecommunications, aerospace, and defense. It offers enhanced performance, a wide range of connectivity options, and robust security features, making it suitable for mission-critical operations.

One of the key features of the MVME7100 is its high-performance processing capabilities. The system is powered by a dual-core PowerPC processor that delivers exceptional computational power while maintaining energy efficiency. This makes the MVME7100 ideal for applications requiring intensive data processing and real-time analytics, allowing users to run complex algorithms and manage large datasets effectively.

The MVME7100 supports an extensive array of I/O options, which ensures compatibility with multiple peripheral devices and communication protocols. Users can take advantage of multiple serial ports, Ethernet interfaces, and USB connections. Additionally, the platform supports various fieldbus protocols, enabling seamless integration with existing systems and equipment.

In terms of ruggedness, the MVME7100 is designed to operate in challenging environments. It features a robust enclosure that can withstand extreme temperatures, shocks, and vibrations. This provides the reliability required for industrial applications, making it suitable for deployment in harsh conditions, such as manufacturing floors or remote locations.

Security is another critical aspect of the MVME7100. It incorporates advanced security measures, including secure boot and encryption capabilities, to protect sensitive data and ensure system integrity. These features are essential for applications in sectors like defense and aerospace, where cybersecurity is a top priority.

Moreover, the MVME7100 supports various operating systems, including VxWorks and Linux, providing flexibility for developers and engineers. This enables the use of popular software development tools and frameworks, facilitating faster application development and deployment.

In summary, the Emerson MVME7100 is a robust embedded computing solution that combines high performance, extensive connectivity, and exceptional reliability. Its versatile features make it suitable for a wide range of applications, ensuring that it meets the needs of industries where performance and security are paramount. Whether deployed in telecommunications, defense, or industrial automation, the MVME7100 stands out as a reliable choice for embedded computing challenges.