Current document about how to boot VxWorks is limited. Add several chapters in README.vxworks to document this. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Tom Rini <trini@konsulko.com>master
parent
9aa1280a56
commit
3619e94ad7
@ -1,19 +1,85 @@ |
||||
From VxWorks 6.9+ (not include 6.9), VxWorks starts adopting device tree as its hardware |
||||
decription mechansim (for PowerPC and ARM), thus requiring boot interface changes. |
||||
# |
||||
# Copyright (C) 2013, Miao Yan <miao.yan@windriver.com> |
||||
# Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com> |
||||
# |
||||
# SPDX-License-Identifier: GPL-2.0+ |
||||
# |
||||
|
||||
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. |
||||
|
||||
64-bit x86 kernel cannot be loaded as of today. |
||||
|
||||
VxWork 7 on PowerPC and ARM |
||||
--------------------------- |
||||
From VxWorks 7, VxWorks starts adopting device tree as its hardware decription |
||||
mechansim (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): |
||||
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) |
||||
void (*kernel_entry)(fdt_addr, 0, 0, EPAPR_MAGIC, boot_IMA, 0, 0) |
||||
|
||||
For ARM, the calling convention is show below: |
||||
|
||||
void (*kernel_entry)(void *fdt_addr) |
||||
|
||||
When booting new VxWorks kernel (uImage format), the parameters passed to bootm is like below: |
||||
When booting new VxWorks kernel (uImage format), the parameters passed to bootm |
||||
is like below: |
||||
|
||||
bootm <kernel image address> - <device tree address> |
||||
|
||||
The do_bootvx command still works as it was for older VxWorks kernels. |
||||
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" 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. |
||||
|
||||
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 loading an x86 kernel, two additional environment variables need to be |
||||
provided. They are "e820data" and "e820info", which represent the address of |
||||
E820 table and E820 information (defined by VxWorks) in system memory. |
||||
|
||||
Check VxWorks kernel configuration to look for BIOS_E820_DATA_START and |
||||
BIOS_E820_INFO_START, and assign their values to "e820data" and "e820info" |
||||
accordingly. If neither of these two are supplied, U-Boot assumes a default |
||||
location at 0x4000 for "e820data" and 0x4a00 for "e820info". Typical values |
||||
for "e820data" and "e820info" are 0x104000 and 0x104a00. But there is one |
||||
exception on Intel Galileo, where "e820data" and "e820info" should be left |
||||
unset, which assume the default location for VxWorks. |
||||
|
||||
Note since currently U-Boot does not support ACPI 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. |
||||
|
Loading…
Reference in new issue