diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.x86 | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/doc/README.x86 b/doc/README.x86 index c69dc1c..8025485 100644 --- a/doc/README.x86 +++ b/doc/README.x86 @@ -18,6 +18,8 @@ U-Boot supports running as a coreboot [1] payload on x86. So far only Link work with minimal adjustments on other x86 boards since coreboot deals with most of the low-level details. +U-Boot is a main bootloader on Intel Edison board. + U-Boot also supports booting directly from x86 reset vector, without coreboot. In this case, known as bare mode, from the fact that it runs on the 'bare metal', U-Boot acts like a BIOS replacement. The following platforms @@ -61,6 +63,16 @@ Change the 'Board configuration file' and 'Board Device Tree Source (dts) file' to point to a new board. You can also change the Cache-As-RAM (CAR) related settings here if the default values do not fit your new board. +Build Instructions for U-Boot as main bootloader +------------------------------------------------ + +Intel Edison instructions: + +Simple you can build U-Boot and obtain u-boot.bin + +$ make edison_defconfig +$ make all + Build Instructions for U-Boot as BIOS replacement (bare mode) ------------------------------------------------------------- Building a ROM version of U-Boot (hereafter referred to as u-boot.rom) is a @@ -455,6 +467,33 @@ Here the kernel (bzImage) is loaded to 01000000 and initrd is to 04000000. Then, => zboot 01000000 - 04000000 1b1ab50 +Updating U-Boot on Edison +------------------------- +By default Intel Edison boards are shipped with preinstalled heavily +patched U-Boot v2014.04. Though it supports DFU which we may be able to +use. + +1. Prepare u-boot.bin as described in chapter above. You still need one +more step (if and only if you have original U-Boot), i.e. run the +following command: + +$ truncate -s %4096 u-boot.bin + +2. Run your board and interrupt booting to U-Boot console. In the console +call: + + => run do_force_flash_os + +3. Wait for few seconds, it will prepare environment variable and runs +DFU. Run DFU command from the host system: + +$ dfu-util -v -d 8087:0a99 --alt u-boot0 -D u-boot.bin + +4. Return to U-Boot console and following hint. i.e. push Ctrl+C, and +reset the board: + + => reset + CPU Microcode ------------- Modern CPUs usually require a special bit stream called microcode [8] to be |