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Overview
This article mainly records parts of the “VxWorks BSP Developer’s Guide 6.9” and “VxBus Device Driver Developer’s Guide 6.9”, focusing on the BSP porting and driver development of VxWorks 6.9.
BSP Overview
This chapter mainly introduces the BSP-related functions called during the VxWorks startup process. The main work of BSP porting is to implement these functions.
| Function | File | Description |
| romInit() | romInit.s | Initialize CPU and memory |
| sysHwInit() | sysLib.c | Hardware peripheral initialization |
| sysHwInit0() | sysLib.c | Complete specific hardware peripheral initialization before sysHwInit(); this function is only needed in some BSPs |
| sysHwInit1() | sysLib.c | Only needed for 64bit, initializes all hardware peripherals and virtual memory |
| sysHwInit2() | sysLib.c | Prepares the hardware peripherals needed for running VxWorks applications |
The source files required for BSP include:
Required BSP Files:
installDir/vxworks-6.x/target/config/bspname/bspname.h
installDir/vxworks-6.x/target/config/bspname/config.h
installDir/vxworks-6.x/target/config/bspname/Makefile
installDir/vxworks-6.x/target/config/bspname/README
installDir/vxworks-6.x/target/config/bspname/romInit.s
installDir/vxworks-6.x/target/config/bspname/sysALib.s
installDir/vxworks-6.x/target/config/bspname/sysLib.c
installDir/vxworks-6.x/target/config/bspname/target.ref
Optional BSP Files:
installDir/vxworks-6.x/target/config/bspname/sysSerial.c
installDir/vxworks-6.x/target/config/bspname/configNet.h
installDir/vxworks-6.x/target/config/bspname/sysEnd.c
VxBus Device Driver Directories:
installDir/vxworks-6.x/target/src/hwif/busCtlr
installDir/vxworks-6.x/target/src/hwif/console
installDir/vxworks-6.x/target/src/hwif/cpu
installDir/vxworks-6.x/target/src/hwif/demo
installDir/vxworks-6.x/target/src/hwif/dmaCtlr
installDir/vxworks-6.x/target/src/hwif/end
installDir/vxworks-6.x/target/src/hwif/end2
installDir/vxworks-6.x/target/src/hwif/fw
installDir/vxworks-6.x/target/src/hwif/h
installDir/vxworks-6.x/target/src/hwif/hEnd
installDir/vxworks-6.x/target/src/hwif/i2c
installDir/vxworks-6.x/target/src/hwif/intCtlr
installDir/vxworks-6.x/target/src/hwif/mf
installDir/vxworks-6.x/target/src/hwif/mii
installDir/vxworks-6.x/target/src/hwif/nvram
installDir/vxworks-6.x/target/src/hwif/resource
installDir/vxworks-6.x/target/src/hwif/sio
installDir/vxworks-6.x/target/src/hwif/spi
installDir/vxworks-6.x/target/src/hwif/storage
installDir/vxworks-6.x/target/src/hwif/timer
installDir/vxworks-6.x/target/src/hwif/usb
installDir/vxworks-6.x/target/src/hwif/util
installDir/vxworks-6.x/target/src/hwif/vxbus
VxWorks Configuration Directories:
installDir/vxworks-6.x/target/config/all
installDir/vxworks-6.x/target/src/config
installDir/vxworks-6.x/target/config/comps
installDir/vxworks-6.x/target/config/comps/src
installDir/vxworks-6.x/target/config/comps/vxWorks
Important source file descriptions:
| prjParams.h | VxWorks component configuration and trimming, automatically generates switch macros (COMPONENTS INCLUDED) and macro parameter (PARAMETERS) files. prjParams.h is usually included by config.h, and prjComps.h is included by target/config/comps/src/configAll.h. |
| prjComps.h | |
| configAll.h | Included by config.h |
| configNet.h | Enhanced network driver configuration file |
| config_pre.h | |
| config.h | |
| sysALib.s | |
| sysLib.c | |
| linkSyms.c | |
| prjConfig.c | Includes config.h, is the entry point for VxWorks applications, as the usrRoot() function in prjConfig.c calls usrAppInit(). Automatically generated when creating or recompiling the VxWorks system image project, used to initialize various components of the VxWorks system, and will reset every time the project is recompiled. |
| usrConfig.c | Used when compiling the bootrom file, functions similarly to prjConfig.c. |
| vxBus.c | |
| usrAppInit.c |
VxWorks Image Startup Process
sysInit : sysALib.s
Disable interrupts, initialize stack, jump to usrInit()
usrInit() : prjConfig.c
sysStart(startType) /* Zero BSS segment, configure exception vector table base address, etc. */
sysHwInit0();
intVecBaseSet ((FUNCPTR *) VEC_BASE_ADRS);
excShowInit();
usrBootHwInit()
cacheLibInit()
excShowInit()
excVecInit()
sysHwInit() /* Peripheral driver initialization */
usrCacheEnable()
objInfoInit()
objLibInit()
vxMemProbeInit()
classListLibInit()
semLibInit()
classLibInit()
kernelBaseInit()
taskCreateHookInit()
sysDebugModeInit()
usrKernelInit()
sysHwInit() : sysLib.c
hardWareInterFaceInit()
usrKernelInit() : usrKernel.c
Calls taskLibInit() to initialize the task library, calculates the memory pool end address memPoolEndAdrs, and finally calls kernelInit()
kernelInit() : kernelLib.c
Initializes and starts the kernel, creates the root stack and TCB from the top of the memory pool, and finally creates the tRootTask task to execute usrRoot() initialization
usrRoot() : prjConfig.c
Initializes memory, system clock, I/O system, standard input/output, exception handling, and adds user applications.
usrAppInit() : usrAppInit.c
User code entry.
VxWorks Device Drivers
VxWorks device drivers can be implemented in two ways: VxBus-enabled and legacy (pre-VxBus). VxBus-based device drivers inherently support SMP (symmetric multiprocessing).
The VxBus driver framework defines a set of standard driver interfaces for the VxWorks kernel and hardware peripherals.
VxBus device drivers consist of three elements: device, driver, and instance.
Applications query each instance through the vxbDevMethodGet() function.
Development Process
Important structures:
struct hcfResource
{
char * name;
UINT32 type;
union
{
char * string;
UINT32 integer;
void * addr;
ULONG longval;
} u;
};
struct hcfDevice
{
char * devName;
int devUnit;
int busType;
int busIndex;
int count;
const struct hcfResource * pResource;
};
1. Implement the vxbDevRegInfo device descriptor structure instance and register the driver through vxbDevRegister(structure vxbDevRegInfo *pDevInfo);
When the VxWorks system starts, it registers the driver through sysHwInit() -> hardWareInterFaceInit() -> hardWareInterFaceBusInit() calling vxbDevRegister().
struct vxbDevRegInfo
{
struct vxbDevRegInfo * pNext;
UINT32 devID;
UINT32 busID;
UINT32 vxbVersion;
char drvName[MAX_DRV_NAME_LEN+1];
struct drvBusFuncs * pDrvBusFuncs;
struct vxbDeviceMethod * pMethods;
BOOL (*devProbe) ( struct vxbDev * pDevInfo);
struct vxbParams * pParamDefaults;
};
pNext is used for bus cascading; if there is no cascading, it is set to NULL.
drvName indicates the device name, and it matches the device and driver; it can only match if it is consistent with the device name in hcfDeviceList.
pMethods provides various methods for the bus, but usually only provides methods specific to that bus, as general methods like open, read, etc., are generally called through system calls of the I/O layer, and they need to be registered separately.
devProbe is used to check if a device of that type currently exists; if probing is not needed, it is set to NULL.
pDrvBusFuncs provides interfaces needed for device initialization:
struct drvBusFuncs
{
void (*devInstanceInit) (struct vxbDev *);
void (*devInstanceInit2) (struct vxbDev *);
void (*devInstanceConnect) (struct vxbDev *);
};
devInstanceInit is called before the VxWorks kernel initializes, while devInstanceInit2 is called after the VxWorks kernel initializes; generally, device initialization is implemented through devInstanceInit2.
devInstanceConnect is used for device connection, and it can usually be omitted; if it depends on other devices, the startup code can be placed here.
2. Add the device to hcfDeviceList;
The hcfDeviceList[] array manages all devices in the VxBus driver framework, and the last member variable pResource of each member descriptor is used to configure device characteristic information, such as serial port baud rate, etc. It can be obtained through the devResourceGet() function.
3. During the startup of the VxWorks system, devices in hcfDeviceList will be instantiated;
The instantiation process is that the VxWorks system traverses the hcfDeviceList[] array, and if hcfDevice->devName matches with vxbDevRegInfo->drvName, it calls the initialization function pointed to, such as devInstanceInit.
4. Add example device driver code in several initialization functions registered in the vxbDevRegInfo device descriptor structure instance;
The vxBusShow command can be used to view all initialized devices.