[U-Boot] [PATCH 15/15] x86: Update README to explain booting Ubuntu on Minnowmax

[Simon Glass]

On 28 July 2015 at 01:50, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Simon,
>
> On Tue, Jul 28, 2015 at 5:47 AM, Simon Glass <sjg at chromium.org> wrote:
>> The steps required to boot a Linux distribution from U-Boot on x86 are not
>> very complicated, but it is a good idea to have these written down in an
>> accessible place.
>>
>> Document how to examine the boot media from U-Boot, how to load a kernel,
>> load a ramdisk, set the kernel boot arguments and start the kernel. With
>> these instructions Ubuntu boots mostly normally on Minnowmax.
>>
>> Note that the TSC timer does not operate correctly and gives warnings in
>> the boot log. I expect that ACPI support will solve this.
>>
>> Signed-off-by: Simon Glass <sjg at chromium.org>
>
> Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
>
> Please see some comments below.
>
>> ---
>>
>>  doc/README.x86 | 275 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 275 insertions(+)
>>
>> diff --git a/doc/README.x86 b/doc/README.x86
>> index 5d71244..5435d79 100644
>> --- a/doc/README.x86
>> +++ b/doc/README.x86
>> @@ -325,6 +325,278 @@ mtrr - List and set the Memory Type Range Registers (MTRR). These are used to
>>          mode to use. U-Boot sets up some reasonable values but you can
>>          adjust then with this command.
>>
>> +Booting Ubuntu
>> +--------------
>> +As an example of how to set up your boot flow with U-Boot, here are
>> +instructions for starting Ubuntu from U-Boot. These instructions have been
>> +testinged on Minnowboard MAX with a SATA driver but are equally applicable on
>
> tested

Fixed

>
>> +other platforms and other media. There are really only four steps and its a
>> +very simple script, but a more detailed explaination is provided here for
>
> explanation

fixed

>
>> +completeness.

[snip]

>> +If you want to put this in a script you can use something like this:
>> +
>> +   setenv bootargs root=UUID=b2aaf743-0418-4d90-94cc-3e6108d7d968 ro
>> +   setenv boot zboot 03000000 0 04000000 \${filesize}
>
> I believe \ is not needed.
>

Otherwise it will set zboot to the value of ${filesize} when you issue
the 'setenv' command. I've added a comment. Let me know if we should
change it.

>> +   setenv bootcmd "ext2load scsi 0:2 03000000 /boot/vmlinuz-3.13.0-58-generic; ext2load scsi 0:2 04000000 /boot/initrd.img-3.13.0-58-generic; run boot"
>> +   saveenv
>> +

[snip]

Applied to u-boot-x86.