121 lines
4.1 KiB
ArmAsm
121 lines
4.1 KiB
ArmAsm
/*******************************************************************************
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* File Name: CyBootAsmGnu.s
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* Version 3.40
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*
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* Description:
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* Assembly routines for GNU as.
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*
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********************************************************************************
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* Copyright 2010-2013, Cypress Semiconductor Corporation. All rights reserved.
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* You may use this file only in accordance with the license, terms, conditions,
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* disclaimers, and limitations in the end user license agreement accompanying
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* the software package with which this file was provided.
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*******************************************************************************/
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.syntax unified
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.text
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.thumb
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/*******************************************************************************
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* Function Name: CyDelayCycles
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********************************************************************************
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*
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* Summary:
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* Delays for the specified number of cycles.
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*
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* Parameters:
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* uint32 cycles: number of cycles to delay.
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*
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* Return:
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* None
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*
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*******************************************************************************/
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/* void CyDelayCycles(uint32 cycles) */
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.align 3 /* Align to 8 byte boundary (2^n) */
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.global CyDelayCycles
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.func CyDelayCycles, CyDelayCycles
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.type CyDelayCycles, %function
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.thumb_func
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CyDelayCycles: /* cycles bytes */
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ADDS r0, r0, #2 /* 1 2 Round to nearest multiple of 4 */
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LSRS r0, r0, #2 /* 1 2 Divide by 4 and set flags */
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BEQ CyDelayCycles_done /* 2 2 Skip if 0 */
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NOP /* 1 2 Loop alignment padding */
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CyDelayCycles_loop:
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SUBS r0, r0, #1 /* 1 2 */
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MOV r0, r0 /* 1 2 Pad loop to power of two cycles */
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BNE CyDelayCycles_loop /* 2 2 */
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CyDelayCycles_done:
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BX lr /* 3 2 */
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.endfunc
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/*******************************************************************************
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* Function Name: CyEnterCriticalSection
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********************************************************************************
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*
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* Summary:
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* CyEnterCriticalSection disables interrupts and returns a value indicating
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* whether interrupts were previously enabled (the actual value depends on
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* whether the device is PSoC 3 or PSoC 5).
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*
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* Note Implementation of CyEnterCriticalSection manipulates the IRQ enable bit
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* with interrupts still enabled. The test and set of the interrupt bits is not
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* atomic; this is true for both PSoC 3 and PSoC 5. Therefore, to avoid
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* corrupting processor state, it must be the policy that all interrupt routines
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* restore the interrupt enable bits as they were found on entry.
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*
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* Parameters:
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* None
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*
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* Return:
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* uint8
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* Returns 0 if interrupts were previously enabled or 1 if interrupts
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* were previously disabled.
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*
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*******************************************************************************/
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/* uint8 CyEnterCriticalSection(void) */
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.global CyEnterCriticalSection
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.func CyEnterCriticalSection, CyEnterCriticalSection
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.type CyEnterCriticalSection, %function
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.thumb_func
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CyEnterCriticalSection:
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MRS r0, PRIMASK /* Save and return interrupt state */
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CPSID I /* Disable interrupts */
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BX lr
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.endfunc
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/*******************************************************************************
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* Function Name: CyExitCriticalSection
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********************************************************************************
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*
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* Summary:
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* CyExitCriticalSection re-enables interrupts if they were enabled before
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* CyEnterCriticalSection was called. The argument should be the value returned
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* from CyEnterCriticalSection.
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*
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* Parameters:
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* uint8 savedIntrStatus:
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* Saved interrupt status returned by the CyEnterCriticalSection function.
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*
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* Return:
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* None
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*
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*******************************************************************************/
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/* void CyExitCriticalSection(uint8 savedIntrStatus) */
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.global CyExitCriticalSection
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.func CyExitCriticalSection, CyExitCriticalSection
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.type CyExitCriticalSection, %function
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.thumb_func
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CyExitCriticalSection:
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MSR PRIMASK, r0 /* Restore interrupt state */
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BX lr
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.endfunc
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.end
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/* [] END OF FILE */
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