GSOC（google summer of code）树莓派bsp rtems的项目进展

相比于bbb板，对于raspberry pi 上的rtems系统的研究开展的更早，也更加成熟，从GSOC的官网可以看到早在2013年，就有项目关于改进rtems 对于树莓派的bsp支持。

主要有以下几点：

1. Secure Digital card read and write support (some initial work using the BSD sdhci driver)
2. Graphics / RTEMS Framebuffer Support
3. USB Device support
4. HDMI/Graphics console (Requires framebuffer support and USB or GPIO connected keyboard device)
5. Ethernet network support (Requires USB support)

首先是2013年的project：

Raspberry Pi BSP Peripherals：

Introduction: This project has provided the Raspberry Pi BSP with support for more peripherals, namely: GPIO driver, I2C and SPI Bus drivers. Unfortunately the Frame Buffer graphics driver support was left out.

2013年的项目还是对于一些外设的通信方式进行拓展，比如I2C和SPI等，还不涉及的网络。

2015 project：

project 1：Low Level Peripherals and SD Card

1. Complete SPI, GPIO, I2C integration (Done)
2. Implement SD Card file system support (Started)
3. Implement Model identification detection and reporting (To be done. Mailbox support was provided but not merged yet by another project)
   • This requires support for the mailbox interface used for graphics. Also the memory size can be dynamically determined this way. In addition to spots where this can make the BSP code more flexible, a method should be provided to the user to get the Pi version.
4. Extra: Implement DMA support for I2C and SPI (To be done)
5. Extra: Implement support for second SPI device on A+/B+/Pi 2 (To be done)
   • If the second SPI device is a second instance of the first device, then support for both should be done in step 1.

project 2：USB Support

1. Implement USB device support using libBSD
2. Implement basic HID support ( keyboard/mouse )
3. Implement USB Ethernet Device support
4. Extra: Implement USB on multiple Pi models
5. Extra: Implement USB storage device support

可以看出，树莓派的rtems以太网通信也还是处于研究阶段，目前国内百度关于这方面的资料也很少，其实国内做的人还是比较多，只是不愿意把成果共享出来。国外的话可能就需要翻墙google。下次再说。