VxWorks API Reference : OS Libraries
vxLib - miscellaneous support routines
vxTas( ) - C-callable atomic test-and-set primitive
vxMemArchProbe( ) - architecture specific part of vxMemProbe
vxMemProbe( ) - probe an address for a bus error
vxSSEnable( ) - enable the superscalar dispatch (MC68060)
vxSSDisable( ) - disable the superscalar dispatch (MC68060)
vxPowerModeSet( ) - set the power management mode (PowerPC, SH, x86)
vxPowerModeGet( ) - get the power management mode (PowerPC, SH, x86)
vxPowerDown( ) - place the processor in reduced-power mode (PowerPC, SH)
vxCr0Get( ) - get a content of the Control Register 0 (x86)
vxCr0Set( ) - set a value to the Control Register 0 (x86)
vxCr2Get( ) - get a content of the Control Register 2 (x86)
vxCr2Set( ) - set a value to the Control Register 2 (x86)
vxCr3Get( ) - get a content of the Control Register 3 (x86)
vxCr3Set( ) - set a value to the Control Register 3 (x86)
vxCr4Get( ) - get a content of the Control Register 4 (x86)
vxCr4Set( ) - set a value to the Control Register 4 (x86)
vxEflagsGet( ) - get a content of the EFLAGS register (x86)
vxEflagsSet( ) - set a value to the EFLAGS register (x86)
vxDrGet( ) - get a content of the Debug Register 0 to 7 (x86)
vxDrSet( ) - set a value to the Debug Register 0 to 7 (x86)
vxTssGet( ) - get a content of the TASK register (x86)
vxTssSet( ) - set a value to the TASK register (x86)
vxGdtrGet( ) - get a content of the Global Descriptor Table Register (x86)
vxIdtrGet( ) - get a content of the Interrupt Descriptor Table Register (x86)
vxLdtrGet( ) - get a content of the Local Descriptor Table Register (x86)
This module contains miscellaneous VxWorks support routines.
vxLib.h
vxTas( ) - C-callable atomic test-and-set primitive
BOOL vxTas ( void * address /* address to test and set */ )
This routine provides a C-callable interface to a test-and-set instruction. The test-and-set instruction is executed on the specified address. The architecture test-and-set instruction is:
68K: tas
x86: lock bts
SH: tas.b
ARM: swpbThis routine is equivalent to sysBusTas( ) in sysLib.
Because VxWorks does not support the MIPS MMU, only kseg0 and kseg1 addresses are accepted; other addresses return FALSE.
BTS "Bit Test and Set" instruction is executed with LOCK instruction prefix to lock the Bus during the execution. The bit position 0 is toggled.
The SH version of vxTas( ) simply executes the tas.b instruction, and the test-and-set (atomic read-modify-write) operation may require an external bus locking mechanism on some hardware. In this case, wrap the vxTas( ) with a bus locking and unlocking code in the sysBusTas( ).
TRUE if the value had not been set (but is now), or FALSE if the value was set already.
vxMemArchProbe( ) - architecture specific part of vxMemProbe
STATUS vxMemArchProbe ( char * adrs, /* address to be probed */ int mode, /* VX_READ or VX_WRITE */ int length, /* 1, 2, 4, or 8 */ char * pVal /* where to return value, or ptr to value */ /* to be written */ )
This is the routine implementing the architecture specific part of the vxMemProbe routine. It traps the relevant exceptions while accessing the specified address. If an exception occurs, then the result will be ERROR. If no exception occurs then the result will be OK.
OK or ERROR if an exception occurred during access.
vxMemProbe( ) - probe an address for a bus error
STATUS vxMemProbe ( char * adrs, /* address to be probed */ int mode, /* VX_READ or VX_WRITE */ int length, /* 1, 2, 4, or 8 */ char * pVal /* where to return value, or ptr to value */ /* to be written */ )
This routine probes a specified address to see if it is readable or writable, as specified by mode. The address is read or written as 1, 2, or 4 bytes, as specified by length (values other than 1, 2, or 4 yield unpredictable results). If the probe is a VX_READ (0), the value read is copied to the location pointed to by pVal. If the probe is a VX_WRITE (1), the value written is taken from the location pointed to by pVal. In either case, pVal should point to a value of 1, 2, or 4 bytes, as specified by length.
Note that only bus errors are trapped during the probe, and that the access must otherwise be valid (i.e., it must not generate an address error).
testMem (adrs) char *adrs; { char testW = 1; char testR; if (vxMemProbe (adrs, VX_WRITE, 1, &testW) == OK) printf ("value %d written to adrs %x\n", testW, adrs); if (vxMemProbe (adrs, VX_READ, 1, &testR) == OK) printf ("value %d read from adrs %x\n", testR, adrs); }
The BSP can modify the behaviour of vxMemProbe( ) by supplying an alternate routine and placing the address in the global variable _func_vxMemProbeHook. The BSP routine will be called instead of the architecture specific routine vxMemArchProbe( ).
OK, or ERROR if the probe caused a bus error or was misaligned.
vxLib, vxMemArchProbe( )
vxSSEnable( ) - enable the superscalar dispatch (MC68060)
void vxSSEnable (void)
This function sets the ESS bit of the Processor Configuration Register (PCR) to enable the superscalar dispatch.
N/A
vxSSDisable( ) - disable the superscalar dispatch (MC68060)
void vxSSDisable (void)
This function resets the ESS bit of the Processor Configuration Register (PCR) to disable the superscalar dispatch.
N/A
vxPowerModeSet( ) - set the power management mode (PowerPC, SH, x86)
STATUS vxPowerModeSet ( UINT32 mode /* power management mode to select */ )
This routine selects the power management mode to be activated when vxPowerDown( ) is called. vxPowerModeSet( ) is normally called in the BSP initialization routine sysHwInit( ).
Power management modes include the following:
- VX_POWER_MODE_DISABLE (0x1)
- Power management is disabled; this prevents the MSR(POW) bit from being set (all PPC).
- VX_POWER_MODE_FULL (0x2)
- All CPU units are active while the kernel is idle (PPC603, PPCEC603 and PPC860 only).
- VX_POWER_MODE_DOZE (0x4)
- Only the decrementer, data cache, and bus snooping are active while the kernel is idle (PPC603, PPCEC603 and PPC860).
- VX_POWER_MODE_NAP (0x8)
- Only the decrementer is active while the kernel is idle (PPC603, PPCEC603 and PPC604 ).
- VX_POWER_MODE_SLEEP (0x10)
- All CPU units are inactive while the kernel is idle (PPC603, PPCEC603 and PPC860 - not recommended for the PPC603 and PPCEC603 architecture).
- VX_POWER_MODE_DEEP_SLEEP (0x20)
- All CPU units are inactive while the kernel is idle (PPC860 only - not recommended).
- VX_POWER_MODE_DPM (0x40)
- Dynamic Power Management Mode (PPC603 and PPCEC603 only).
- VX_POWER_MODE_DOWN (0x80)
- Only a hard reset causes an exit from power-down low power mode (PPC860 only - not recommended).
Power management modes include the following:
- VX_POWER_MODE_DISABLE (0x0)
- Power management is disabled.
- VX_POWER_MODE_SLEEP (0x1)
- The core CPU is halted, on-chip peripherals operating, external memory refreshing.
- VX_POWER_MODE_DEEP_SLEEP (0x2)
- The core CPU is halted, on-chip peripherals operating, external memory self-refreshing (SH-4 only).
- VX_POWER_MODE_USER (0xff)
- Set up to three 8-bit standby registers with user-specified values:
vxPowerModeSet (VX_POWER_MODE_USER | sbr1<<8 | sbr2<<16 | sbr3<<24);The sbr1 value is written to the STBCR or SBYCR1, sbr2 is written to the STBCR2 or SBYCR2, and sbr3 is written to the STBCR3 register (when available), depending on the SH processor type.
vxPowerModeSet( ) is called in the BSP initialization routine sysHwInit( ). Power management modes include the following:
- VX_POWER_MODE_DISABLE (0x1)
- Power management is disable: this prevents halting the CPU.
- VX_POWER_MODE_AUTOHALT (0x4)
- Power management is enable: this allows halting the CPU.
OK, or ERROR if mode is incorrect or not supported by the processor.
vxLib, vxPowerModeGet( ), vxPowerDown( )
vxPowerModeGet( ) - get the power management mode (PowerPC, SH, x86)
UINT32 vxPowerModeGet (void)
This routine returns the power management mode set by vxPowerModeSet( ).
The power management mode, or ERROR if no mode has been selected or if power management is not supported.
vxLib, vxPowerModeSet( ), vxPowerDown( )
vxPowerDown( ) - place the processor in reduced-power mode (PowerPC, SH)
UINT32 vxPowerDown (void)
This routine activates the reduced-power mode if power management is enabled. It is called by the scheduler when the kernel enters the idle loop. The power management mode is selected by vxPowerModeSet( ).
OK, or ERROR if power management is not supported or if external interrupts are disabled.
vxLib, vxPowerModeSet( ), vxPowerModeGet( )
vxCr0Get( ) - get a content of the Control Register 0 (x86)
int vxCr0Get (void)
This routine gets a content of the Control Register 0.
a value of the Control Register 0
vxCr0Set( ) - set a value to the Control Register 0 (x86)
void vxCr0Set ( int value /* CR0 value */ )
This routine sets a value to the Control Register 0.
N/A
vxCr2Get( ) - get a content of the Control Register 2 (x86)
int vxCr2Get (void)
This routine gets a content of the Control Register 2.
a value of the Control Register 2
vxCr2Set( ) - set a value to the Control Register 2 (x86)
void vxCr2Set ( int value /* CR2 value */ )
This routine sets a value to the Control Register 2.
N/A
vxCr3Get( ) - get a content of the Control Register 3 (x86)
int vxCr3Get (void)
This routine gets a content of the Control Register 3.
a value of the Control Register 3
vxCr3Set( ) - set a value to the Control Register 3 (x86)
void vxCr3Set ( int value /* CR3 value */ )
This routine sets a value to the Control Register 3.
N/A
vxCr4Get( ) - get a content of the Control Register 4 (x86)
int vxCr4Get (void)
This routine gets a content of the Control Register 4.
a value of the Control Register 4
vxCr4Set( ) - set a value to the Control Register 4 (x86)
void vxCr4Set ( int value /* CR4 value */ )
This routine sets a value to the Control Register 4.
N/A
vxEflagsGet( ) - get a content of the EFLAGS register (x86)
int vxEflagsGet (void)
This routine gets a content of the EFLAGS register
a value of the EFLAGS register
vxEflagsSet( ) - set a value to the EFLAGS register (x86)
void vxEflagsSet ( int value /* EFLAGS value */ )
This routine sets a value to the EFLAGS register
N/A
vxDrGet( ) - get a content of the Debug Register 0 to 7 (x86)
void vxDrGet ( int * pDr0, /* DR0 */ int * pDr1, /* DR1 */ int * pDr2, /* DR2 */ int * pDr3, /* DR3 */ int * pDr4, /* DR4 */ int * pDr5, /* DR5 */ int * pDr6, /* DR6 */ int * pDr7 /* DR7 */ )
This routine gets a content of the Debug Register 0 to 7.
N/A
vxDrSet( ) - set a value to the Debug Register 0 to 7 (x86)
void vxDrSet ( int dr0, /* DR0 */ int dr1, /* DR1 */ int dr2, /* DR2 */ int dr3, /* DR3 */ int dr4, /* DR4 */ int dr5, /* DR5 */ int dr6, /* DR6 */ int dr7 /* DR7 */ )
This routine sets a value to the Debug Register 0 to 7.
N/A
vxTssGet( ) - get a content of the TASK register (x86)
int vxTssGet (void)
This routine gets a content of the TASK register
a value of the TASK register
vxTssSet( ) - set a value to the TASK register (x86)
void vxTssSet ( int value /* TASK register value */ )
This routine sets a value to the TASK register
N/A
vxGdtrGet( ) - get a content of the Global Descriptor Table Register (x86)
void vxGdtrGet ( long long int * pGdtr /* memory to store GDTR */ )
This routine gets a content of the Global Descriptor Table Register
N/A
vxIdtrGet( ) - get a content of the Interrupt Descriptor Table Register (x86)
void vxIdtrGet ( long long int * pIdtr /* memory to store IDTR */ )
This routine gets a content of the Interrupt Descriptor Table Register
N/A
vxLdtrGet( ) - get a content of the Local Descriptor Table Register (x86)
void vxLdtrGet ( long long int * pLdtr /* memory to store LDTR */ )
This routine gets a content of the Local Descriptor Table Register
N/A