Difference between revisions of "Bering-uClibc 5.x - User Guide - Appendices - Hardware-Specific Guides"

From bering-uClibc
Jump to: navigation, search
(Created)
 
(Confirmed details for Raspberry Pi *.bin files)
Line 34: Line 34:
 
The first disk partition must be formatted as a FAT-32 filesystem which must contain:
 
The first disk partition must be formatted as a FAT-32 filesystem which must contain:
 
* A file called <code class="filename">start.elf</code> which contains the GPU binary driver
 
* A file called <code class="filename">start.elf</code> which contains the GPU binary driver
−
* A file called <code class="filename">bootcode.bin</code> which is presumably referenced by the GPU binary driver
+
* A file called <code class="filename">bootcode.bin</code> which is the second stage bootloader
−
* A file called <code class="filename">loader.bin</code> which is presumably referenced by the GPU binary driver
+
* A file called <code class="filename">loader.bin</code> which is the third stage bootloader
 
* A file called <code class="filename">kernel.img</code> which is the Linux kernel
 
* A file called <code class="filename">kernel.img</code> which is the Linux kernel
−
** This seems to be a standard Linux kernel <code class="filename">Image</code> file with a special 32KB prefix. See [http://www.cnx-software.com/2012/01/22/linux-kernel-3-1-9-for-raspberry-pi-released/ here]
+
** This seems to be a standard (uncompressed) Linux kernel <code class="filename">Image</code> file with a special 32KB prefix. See [http://www.cnx-software.com/2012/01/22/linux-kernel-3-1-9-for-raspberry-pi-released/ here]
 
* A file called <code class="filename">cmdline.txt</code> containing the kernel command line
 
* A file called <code class="filename">cmdline.txt</code> containing the kernel command line
  

Revision as of 14:48, 6 April 2012

ARM CPU Architecture

ARM Versatile Platform Baseboards

Overview

The ARM® Versatile™ system boards are primarily relevant to Bering-uClibc because they are well supported and tested targets for the QEMU ARM emulator which is invaluable when developing Bering-uClibc 5.x implementations which target physical ARM processor hardware.

Several different CPU variants are available:

  • ARM926EJ-S
  • ARM1176JZF-S
    • Same processor as the Raspberry Pi but only supported by very recent versions of QEMU; confirmed as present in QEMU 1.0.1
  • ARM11MPCore
  • Coretex-A8

Hardware / Driver Details

  • The network controller chip is an SMSC LAN91C11x (SMC91C11xFD) and needs kernel Module smc91x.ko
  • The disk controller chip is an LSI Logic / Symbios Logic 53C895a and needs kernel Module sym53c8xx.ko
    • This is a SCSI disk controller. Disk devices appear as e.g. /dev/sda


Raspberry Pi

Overview

The Raspberry Pi is a physically small and very low-cost single board computer. It has a Broadcom BCM2835 "system on a chip" integrated circuit containing an ARM1176JZF-S CPU which implements the ARMv6 architecture standard. The BCM2835 contains a variety of devices. Many of these seem to be identified with the string BCM2708 rather than BCM2835. The Raspberry Pi foundation have added a specific bcm2708 "platform" to a branch of the Linux kernel source. See the Raspberry Pi Git Hub repository

Hardware / Driver Details

Refer to the example boot log here

  • The network controller chip is an ???
  • The disk controller chip is an ???

Boot Disk Layout

The Raspberry Pi must boot from its SD card and some vital files must be present in the right location.

The first disk partition must be formatted as a FAT-32 filesystem which must contain:

  • A file called start.elf which contains the GPU binary driver
  • A file called bootcode.bin which is the second stage bootloader
  • A file called loader.bin which is the third stage bootloader
  • A file called kernel.img which is the Linux kernel
    • This seems to be a standard (uncompressed) Linux kernel Image file with a special 32KB prefix. See here
  • A file called cmdline.txt containing the kernel command line

There does not seem to be any standard provision for loading an initramfs (initrd) file. We probably need to embed the initrd into the kernel.

It seems customary to put the files relating to a particular Linux distribution on a second disk partition. We therefore need a second FAT-32 disk partition for leaf.cfg, all the .lrp Package files etc.

Note that the Raspberry Pi references the first disk partition as /dev/mmcblk0p1 and the second disk partition as /dev/mmcblk0p2.

Retrieved from "http://bering-uclibc.zetam.org/index.php?title=Bering-uClibc_5.x_-_User_Guide_-_Appendices_-_Hardware-Specific_Guides&oldid=1017"