Bin Meng | 6ab240d | 2015-10-07 20:19:20 -0700 | [diff] [blame] | 1 | # |
| 2 | # Copyright (C) 2013, Miao Yan <miao.yan@windriver.com> |
| 3 | # Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com> |
| 4 | # |
| 5 | # SPDX-License-Identifier: GPL-2.0+ |
| 6 | # |
| 7 | |
| 8 | VxWorks Support |
| 9 | =============== |
| 10 | |
| 11 | This document describes the information about U-Boot loading VxWorks kernel. |
| 12 | |
| 13 | Status |
| 14 | ------ |
| 15 | U-Boot supports loading VxWorks kernels via 'bootvx' and 'bootm' commands. |
| 16 | For booting old kernels (6.9.x) on PowerPC and ARM, and all kernel versions |
| 17 | on other architectures, 'bootvx' shall be used. For booting VxWorks 7 kernels |
| 18 | on PowerPC and ARM, 'bootm' shall be used. |
| 19 | |
Bin Meng | e154454 | 2018-04-11 22:02:06 -0700 | [diff] [blame] | 20 | VxWorks 7 on PowerPC and ARM |
Bin Meng | 6ab240d | 2015-10-07 20:19:20 -0700 | [diff] [blame] | 21 | --------------------------- |
| 22 | From VxWorks 7, VxWorks starts adopting device tree as its hardware decription |
| 23 | mechansim (for PowerPC and ARM), thus requiring boot interface changes. |
Miao Yan | aed1458 | 2013-11-28 17:51:40 +0800 | [diff] [blame] | 24 | This section will describe the new interface. |
| 25 | |
Bin Meng | 6ab240d | 2015-10-07 20:19:20 -0700 | [diff] [blame] | 26 | For PowerPC, the calling convention of the new VxWorks entry point conforms to |
| 27 | the ePAPR standard, which is shown below (see ePAPR for more details): |
Miao Yan | aed1458 | 2013-11-28 17:51:40 +0800 | [diff] [blame] | 28 | |
Bin Meng | 6ab240d | 2015-10-07 20:19:20 -0700 | [diff] [blame] | 29 | void (*kernel_entry)(fdt_addr, 0, 0, EPAPR_MAGIC, boot_IMA, 0, 0) |
Miao Yan | aed1458 | 2013-11-28 17:51:40 +0800 | [diff] [blame] | 30 | |
Bin Meng | e154454 | 2018-04-11 22:02:06 -0700 | [diff] [blame] | 31 | For ARM, the calling convention is shown below: |
Miao Yan | aed1458 | 2013-11-28 17:51:40 +0800 | [diff] [blame] | 32 | |
| 33 | void (*kernel_entry)(void *fdt_addr) |
| 34 | |
Bin Meng | e154454 | 2018-04-11 22:02:06 -0700 | [diff] [blame] | 35 | When booting a VxWorks 7 kernel (uImage format), the parameters passed to bootm |
Bin Meng | 6ab240d | 2015-10-07 20:19:20 -0700 | [diff] [blame] | 36 | is like below: |
Miao Yan | aed1458 | 2013-11-28 17:51:40 +0800 | [diff] [blame] | 37 | |
| 38 | bootm <kernel image address> - <device tree address> |
| 39 | |
Bin Meng | 6ab240d | 2015-10-07 20:19:20 -0700 | [diff] [blame] | 40 | VxWorks bootline |
| 41 | ---------------- |
| 42 | When using 'bootvx', the kernel bootline must be prepared by U-Boot at a |
| 43 | board-specific address before loading VxWorks. U-Boot supplies its address |
| 44 | via "bootaddr" environment variable. To check where the bootline should be |
| 45 | for a specific board, go to the VxWorks BSP for that board, and look for a |
| 46 | parameter called BOOT_LINE_ADRS. Assign its value to "bootaddr". A typical |
Bin Meng | e154454 | 2018-04-11 22:02:06 -0700 | [diff] [blame] | 47 | value for "bootaddr" on an x86 board is 0x101200. |
Bin Meng | 6ab240d | 2015-10-07 20:19:20 -0700 | [diff] [blame] | 48 | |
| 49 | If a "bootargs" variable is defined, its content will be copied to the memory |
| 50 | location pointed by "bootaddr" as the kernel bootline. If "bootargs" is not |
| 51 | there, command 'bootvx' can construct a valid bootline using the following |
| 52 | environments variables: bootdev, bootfile, ipaddr, netmask, serverip, |
| 53 | gatewayip, hostname, othbootargs. |
| 54 | |
| 55 | When using 'bootm', just define "bootargs" in the environment and U-Boot will |
| 56 | handle bootline fix up for the kernel dtb automatically. |
| 57 | |
| 58 | Serial console |
| 59 | -------------- |
| 60 | It's very common that VxWorks BSPs configure a different baud rate for the |
| 61 | serial console from what is being used by U-Boot. For example, VxWorks tends |
| 62 | to use 9600 as the default baud rate on all x86 BSPs while U-Boot uses 115200. |
| 63 | Please configure both U-Boot and VxWorks to use the same baud rate, or it may |
| 64 | look like VxWorks hangs somewhere as nothing outputs on the serial console. |
| 65 | |
| 66 | x86-specific information |
| 67 | ------------------------ |
Bin Meng | e3be890 | 2018-04-11 22:02:07 -0700 | [diff] [blame] | 68 | Before loading an x86 kernel, one additional environment variable need to be |
| 69 | provided. This is "vx_phys_mem_base", which represent the physical memory |
| 70 | base address of VxWorks. |
Bin Meng | 6ab240d | 2015-10-07 20:19:20 -0700 | [diff] [blame] | 71 | |
Bin Meng | e3be890 | 2018-04-11 22:02:07 -0700 | [diff] [blame] | 72 | Check VxWorks kernel configuration to look for LOCAL_MEM_LOCAL_ADRS. For |
| 73 | VxWorks 7, this is normally a virtual address and you need find out its |
| 74 | corresponding physical address and assign its value to "vx_phys_mem_base". |
Bin Meng | 6ab240d | 2015-10-07 20:19:20 -0700 | [diff] [blame] | 75 | |
Bin Meng | e154454 | 2018-04-11 22:02:06 -0700 | [diff] [blame] | 76 | For boards on which ACPI is not supported by U-Boot yet, VxWorks kernel must |
Bin Meng | 6ab240d | 2015-10-07 20:19:20 -0700 | [diff] [blame] | 77 | be configured to use MP table and virtual wire interrupt mode. This requires |
| 78 | INCLUDE_MPTABLE_BOOT_OP and INCLUDE_VIRTUAL_WIRE_MODE to be included in a |
| 79 | VxWorks kernel configuration. |
Bin Meng | a002455 | 2018-04-11 22:02:23 -0700 | [diff] [blame] | 80 | |
| 81 | Both 32-bit x86 and 64-bit x64 kernels can be loaded. |
| 82 | |
| 83 | There are two types of graphics console drivers in VxWorks. One is the 80x25 |
| 84 | VGA text mode driver. The other one is the EFI console bitmapped graphics mode |
| 85 | driver. To make these drivers function, U-Boot needs to load and run the VGA |
| 86 | BIOS of the graphics card first. |
| 87 | |
| 88 | - If the kernel is configured with 80x25 VGA text mode driver, |
| 89 | CONFIG_FRAMEBUFFER_SET_VESA_MODE must be unset in U-Boot. |
| 90 | - If the kernel is configured with bitmapped graphics mode driver, |
| 91 | CONFIG_FRAMEBUFFER_SET_VESA_MODE need remain set but care must be taken |
| 92 | at which VESA mode is to be set. The supported pixel format is 32-bit |
| 93 | RGBA, hence the available VESA mode can only be one of the following: |
| 94 | * FRAMEBUFFER_VESA_MODE_10F |
| 95 | * FRAMEBUFFER_VESA_MODE_112 |
| 96 | * FRAMEBUFFER_VESA_MODE_115 |
| 97 | * FRAMEBUFFER_VESA_MODE_118 |
| 98 | * FRAMEBUFFER_VESA_MODE_11B |