doc: usage: Convert README.vxworks to reST

This converts the existing README.vxworks to reST, and puts it under
the doc/usage/os directory.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

doc/usage/index.rst

@@ -53,3 +53,11 @@ Shell commands
    cmd/true
    cmd/ums
    cmd/wdt
+
+Booting OS
+----------
+
+.. toctree::
+   :maxdepth: 1
+
+   os/vxworks

doc/README.vxworks → doc/usage/os/vxworks.rst

-# SPDX-License-Identifier: GPL-2.0+
-#
-# Copyright (C) 2013, Miao Yan <miao.yan@windriver.com>
-# Copyright (C) 2015-2018, Bin Meng <bmeng.cn@gmail.com>
-# Copyright (C) 2019, Lihua Zhao <lihua.zhao@windriver.com>
+.. SPDX-License-Identifier: GPL-2.0+
+.. Copyright (C) 2013, Miao Yan <miao.yan@windriver.com>
+.. Copyright (C) 2015-2018, Bin Meng <bmeng.cn@gmail.com>
+.. Copyright (C) 2019, Lihua Zhao <lihua.zhao@windriver.com>
 
-VxWorks Support
-===============
+VxWorks
+=======
 
 This document describes the information about U-Boot loading VxWorks kernel.
 
@@ -20,7 +19,7 @@ With CONFIG_EFI_LOADER option, it's possible to chain load a VxWorks x86 kernel
 via the UEFI boot loader application for VxWorks loaded by 'bootefi' command.
 
 VxWorks 7 on PowerPC and ARM
----------------------------
+----------------------------
 From VxWorks 7, VxWorks starts adopting device tree as its hardware description
 mechanism (for PowerPC and ARM), thus requiring boot interface changes.
 This section will describe the new interface.
@@ -37,17 +36,21 @@ is cleared. The calling convention is described below:
 For PowerPC, the calling convention of the new VxWorks entry point conforms to
 the ePAPR standard, which is shown below (see ePAPR for more details):
 
+.. code-block:: c
+
     void (*kernel_entry)(fdt_addr, 0, 0, EPAPR_MAGIC, boot_IMA, 0, 0)
 
 For ARM, the calling convention is shown below:
 
+.. code-block:: c
+
     void (*kernel_entry)(void *fdt_addr)
 
 When using the Linux compatible standard DTB, the calling convention of VxWorks
 entry point is exactly the same as the Linux kernel.
 
 When booting a VxWorks 7 kernel (uImage format), the parameters passed to bootm
-is like below:
+is like below::
 
     bootm <kernel image address> - <device tree address>
 
@@ -108,6 +111,7 @@ BIOS of the graphics card first.
       CONFIG_FRAMEBUFFER_SET_VESA_MODE need remain set but care must be taken
       at which VESA mode is to be set. The supported pixel format is 32-bit
       RGBA, hence the available VESA mode can only be one of the following:
+
         * FRAMEBUFFER_VESA_MODE_10F
         * FRAMEBUFFER_VESA_MODE_112
         * FRAMEBUFFER_VESA_MODE_115