[U-Boot] [PATCH] x86: Add clarifications to the x86 README

[Simon Glass]

On 13 August 2015 at 07:54, Bin Meng <bmeng.cn at gmail.com> wrote:
> On Thu, Aug 13, 2015 at 9:43 PM, Igor Stoppa <igor.stoppa at intel.com> wrote:
>> * Explicitly list the targets supported in each section of the
>> instructions from the x86 README.
>>
>> * Drop references to 'raw mode', in favor of 'bare mode'.
>>
>> Signed-off-by: Igor Stoppa <igor.stoppa at intel.com>
>> ---
>>  doc/README.x86 | 32 +++++++++++++++++++++-----------
>>  1 file changed, 21 insertions(+), 11 deletions(-)
>>
>> diff --git a/doc/README.x86 b/doc/README.x86
>> index af2459c..9012541 100644
>> --- a/doc/README.x86
>> +++ b/doc/README.x86
>> @@ -18,15 +18,16 @@ 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 also supports booting directly from x86 reset vector without coreboot,
>> -aka raw support or bare support. Currently Link, QEMU x86 targets and all
>> -Intel boards support running U-Boot 'bare metal'.
>> +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. Currently Link, QEMU x86
>> +targets and all Intel boards support running U-Boot 'bare metal'.
>>
>>  As for loading an OS, U-Boot supports directly booting a 32-bit or 64-bit
>>  Linux kernel as part of a FIT image. It also supports a compressed zImage.
>>
>> -Build Instructions
>> -------------------
>> +Build Instructions for U-Boot as coreboot payload
>> +-------------------------------------------------
>>  Building U-Boot as a coreboot payload is just like building U-Boot for targets
>>  on other architectures, like below:
>>
>> @@ -48,6 +49,8 @@ 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 BIOS replacement (bare mode)
>> +-------------------------------------------------------------
>>  Building a ROM version of U-Boot (hereafter referred to as u-boot.rom) is a
>>  little bit tricky, as generally it requires several binary blobs which are not
>>  shipped in the U-Boot source tree. Due to this reason, the u-boot.rom build is
>> @@ -58,7 +61,9 @@ $ export BUILD_ROM=y
>>
>>  This tells the Makefile to build u-boot.rom as a target.
>>
>> -Link-specific instructions:
>> +---
>> +
>> +Chromebook Link specific instructions for bare mode:
>>
>>  First, you need the following binary blobs:
>>
>> @@ -87,7 +92,9 @@ Now you can build U-Boot and obtain u-boot.rom:
>>  $ make chromebook_link_defconfig
>>  $ make all
>>
>> -Intel Crown Bay specific instructions:
>> +---
>> +
>> +Intel Crown Bay specific instructions for bare mode:
>>
>>  U-Boot support of Intel Crown Bay board [4] relies on a binary blob called
>>  Firmware Support Package [5] to perform all the necessary initialization steps
>> @@ -122,7 +129,9 @@ Now you can build U-Boot and obtain u-boot.rom
>>  $ make crownbay_defconfig
>>  $ make all
>>
>> -Intel Minnowboard Max instructions:
>> +---
>> +
>> +Intel Minnowboard Max instructions for bare mode:
>>
>>  This uses as FSP as with Crown Bay, except it is for the Atom E3800 series.
>>  Download this and get the .fd file (BAYTRAIL_FSP_GOLD_003_16-SEP-2014.fd at
>> @@ -188,8 +197,9 @@ Offset   Description         Controlling config
>>
>>  Overall ROM image size is controlled by CONFIG_ROM_SIZE.
>>
>> +---
>>
>> -Intel Galileo instructions:
>> +Intel Galileo instructions for bare mode:
>>
>>  Only one binary blob is needed for Remote Management Unit (RMU) within Intel
>>  Quark SoC. Not like FSP, U-Boot does not call into the binary. The binary is
>> @@ -252,8 +262,8 @@ At present it seems that for Minnowboard Max, coreboot does not pass through
>>  the video information correctly (it always says the resolution is 0x0). This
>>  works correctly for link though.
>>
>> -Test with QEMU
>> ---------------
>> +Test with QEMU for bare mode
>> +----------------------------
>>  QEMU is a fancy emulator that can enable us to test U-Boot without access to
>>  a real x86 board. Please make sure your QEMU version is 2.3.0 or above test
>>  U-Boot. To launch QEMU with u-boot.rom, call QEMU as follows:
>> --
>
> Reviewed-by: Bin Meng <bmeng.cn at gmail.com>

Applied to u-boot-x86, thanks!