mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-31 06:18:51 +09:00
![Bin Meng](/assets/img/avatar_default.png)
This updates the doc to mention chain-loading an x86 kernel via 'bootefi' command, along with several typos fix. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Simon Glass <sjg@chromium.org> Reviewed-by: Alexander Graf <agraf@suse.de>
103 lines
4.5 KiB
Plaintext
103 lines
4.5 KiB
Plaintext
# 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>
|
|
|
|
VxWorks Support
|
|
===============
|
|
|
|
This document describes the information about U-Boot loading VxWorks kernel.
|
|
|
|
Status
|
|
------
|
|
U-Boot supports loading VxWorks kernels via 'bootvx' and 'bootm' commands.
|
|
For booting old kernels (6.9.x) on PowerPC and ARM, and all kernel versions
|
|
on other architectures, 'bootvx' shall be used. For booting VxWorks 7 kernels
|
|
on PowerPC and ARM, 'bootm' shall be used.
|
|
|
|
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.
|
|
|
|
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):
|
|
|
|
void (*kernel_entry)(fdt_addr, 0, 0, EPAPR_MAGIC, boot_IMA, 0, 0)
|
|
|
|
For ARM, the calling convention is shown below:
|
|
|
|
void (*kernel_entry)(void *fdt_addr)
|
|
|
|
When booting a VxWorks 7 kernel (uImage format), the parameters passed to bootm
|
|
is like below:
|
|
|
|
bootm <kernel image address> - <device tree address>
|
|
|
|
VxWorks bootline
|
|
----------------
|
|
When using 'bootvx', the kernel bootline must be prepared by U-Boot at a
|
|
board-specific address before loading VxWorks. U-Boot supplies its address
|
|
via "bootaddr" environment variable. To check where the bootline should be
|
|
for a specific board, go to the VxWorks BSP for that board, and look for a
|
|
parameter called BOOT_LINE_ADRS. Assign its value to "bootaddr". A typical
|
|
value for "bootaddr" on an x86 board is 0x101200.
|
|
|
|
If a "bootargs" variable is defined, its content will be copied to the memory
|
|
location pointed by "bootaddr" as the kernel bootline. If "bootargs" is not
|
|
there, command 'bootvx' can construct a valid bootline using the following
|
|
environments variables: bootdev, bootfile, ipaddr, netmask, serverip,
|
|
gatewayip, hostname, othbootargs.
|
|
|
|
When using 'bootm', just define "bootargs" in the environment and U-Boot will
|
|
handle bootline fix up for the kernel dtb automatically.
|
|
|
|
When using 'bootefi' to chain load an x86 kernel, the UEFI boot loader
|
|
application for VxWorks takes care of the kernel bootline preparation.
|
|
|
|
Serial console
|
|
--------------
|
|
It's very common that VxWorks BSPs configure a different baud rate for the
|
|
serial console from what is being used by U-Boot. For example, VxWorks tends
|
|
to use 9600 as the default baud rate on all x86 BSPs while U-Boot uses 115200.
|
|
Please configure both U-Boot and VxWorks to use the same baud rate, or it may
|
|
look like VxWorks hangs somewhere as nothing outputs on the serial console.
|
|
|
|
x86-specific information
|
|
------------------------
|
|
Before direct loading an x86 kernel via 'bootvx', one additional environment
|
|
variable need to be provided. This is "vx_phys_mem_base", which represent the
|
|
physical memory base address of VxWorks.
|
|
|
|
Check VxWorks kernel configuration to look for LOCAL_MEM_LOCAL_ADRS. For
|
|
VxWorks 7, this is normally a virtual address and you need find out its
|
|
corresponding physical address and assign its value to "vx_phys_mem_base".
|
|
|
|
For boards on which ACPI is not supported by U-Boot yet, VxWorks kernel must
|
|
be configured to use MP table and virtual wire interrupt mode. This requires
|
|
INCLUDE_MPTABLE_BOOT_OP and INCLUDE_VIRTUAL_WIRE_MODE to be included in a
|
|
VxWorks kernel configuration.
|
|
|
|
Both 32-bit x86 and 64-bit x64 kernels can be loaded.
|
|
|
|
There are two types of graphics console drivers in VxWorks. One is the 80x25
|
|
VGA text mode driver. The other one is the EFI console bitmapped graphics mode
|
|
driver. To make these drivers function, U-Boot needs to load and run the VGA
|
|
BIOS of the graphics card first.
|
|
|
|
- If the kernel is configured with 80x25 VGA text mode driver,
|
|
CONFIG_FRAMEBUFFER_SET_VESA_MODE must be unset in U-Boot.
|
|
- If the kernel is configured with bitmapped graphics mode driver,
|
|
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
|
|
* FRAMEBUFFER_VESA_MODE_118
|
|
* FRAMEBUFFER_VESA_MODE_11B
|