FreeCalypso > hg > freecalypso-sw
diff nuc-fw/nucleus/irqshell.S @ 79:947b1f473960
beginning of nuc-fw
| author | Michael Spacefalcon <msokolov@ivan.Harhan.ORG> |
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| date | Sun, 11 Aug 2013 07:17:25 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/nuc-fw/nucleus/irqshell.S Sun Aug 11 07:17:25 2013 +0000 @@ -0,0 +1,584 @@ +/* + * FreeNucleus Calypso port by Michael Spacefalcon + * + * This assembly module contains IRQ handler shell + * and some closely related support functions. + * + * The approach to IRQ handling implemented in the present version + * is exactly the same as was found in XVilka's original nucleus_plus.tar.gz + * code targeting OMAP1510. I personally consider it very dumb and + * suboptimal, but the present version is merely a proof of concept - + * changing as little as possible from our starting point will (hopefully) + * make it easier to get this code to compile, link and maybe even run. + */ + +#include "asm_defs.h" +#include "calirq.h" + + .code 32 + +/* + ********************************** + * GLOBAL VARIABLE DECLARATIONS * + ********************************** + */ + + .data + +@ Define vector table used by INT_IRQ to branch to necessary ISR + + .globl INT_IRQ_Vectors +INT_IRQ_Vectors: + .word INT_Interrupt_Shell @ Vector 0 + .word INT_Interrupt_Shell @ Vector 1 + .word INT_Timer_Interrupt @ Vector 2 - TIMER2 + .word INT_Interrupt_Shell @ Vector 3 + .word INT_Interrupt_Shell @ Vector 4 + .word INT_Interrupt_Shell @ Vector 5 + .word INT_Interrupt_Shell @ Vector 6 + .word INT_Interrupt_Shell @ Vector 7 + .word INT_Interrupt_Shell @ Vector 8 + .word INT_Interrupt_Shell @ Vector 9 + .word INT_Interrupt_Shell @ Vector 10 + .word INT_Interrupt_Shell @ Vector 11 + .word INT_Interrupt_Shell @ Vector 12 + .word INT_Interrupt_Shell @ Vector 13 + .word INT_Interrupt_Shell @ Vector 14 + .word INT_Interrupt_Shell @ Vector 15 + .word INT_Interrupt_Shell @ Vector 16 + .word INT_Interrupt_Shell @ Vector 17 + .word INT_Interrupt_Shell @ Vector 18 + .word INT_Interrupt_Shell @ Vector 19 + .word INT_Interrupt_Shell @ Vector 20 + +@ Define the order in which the interrupts will be executed by software(INT_IRQ) +@ Level 1 Interrupt Handler + .globl INT_IRQ_Priority +INT_IRQ_Priority: + .word 0 + .word 1 + .word 2 + .word 3 + .word 4 + .word 5 + .word 6 + .word 7 + .word 8 + .word 9 + .word 10 + .word 11 + .word 12 + .word 13 + .word 14 + .word 15 + .word 16 + .word 17 + .word 18 + .word 19 + .word 20 +INT_Priority_End: + + .text + +/* + ************************************************************************ + * + * FUNCTION + * + * INT_Setup_Vector + * + * DESCRIPTION + * + * This function sets up the specified vector with the new vector + * value. The previous vector value is returned to the caller. + * + * + * Major Revision: + * + * M. Kyle Craig, Accelerated Technology, Inc. + * + * + * + * CALLED BY + * + * Application + * TCC_Register_LISR Register LISR for vector + * + * CALLS + * + * None + * + * INPUTS + * + * vector Vector number to setup + * new Pointer to new assembly + * language ISR + * + * OUTPUTS + * + * old vector contents + * + * HISTORY + * + * NAME DATE REMARKS + * + * W. Lamie 08-27-1994 Created initial version 1.0 + * D. Lamie 08-27-1994 Verified version 1.0 + * + ************************************************************************ + */ + +@VOID *INT_Setup_Vector(INT vector, VOID *new) +@{ + + .globl INT_Setup_Vector +INT_Setup_Vector: + +@VOID *old_vector; /* Old interrupt vector */ +@VOID **vector_table; /* Pointer to vector table */ + +@ Calculate the starting address of the actual vector table. +@ vector_table = (VOID **) 0; + +@ Pickup the old interrupt vector. +@ old_vector = vector_table[vector]; +@ +@ Setup the new interrupt vector. +@ vector_table[vector] = new; +@ +@ Return the old interrupt vector. +@ return(old_vector); + + + LDR r2, =INT_IRQ_Vectors @ Load the vector table address + MOV r0, r0, LSL #2 @ Multiply vector by 4 to get offset into table + LDR r3, [r2,r0] @ Load the old pointer + STR r1, [r2,r0] @ Store the new pointer into the vector table + + MOV r0, r3 @ Put the old pointer into the return register + + BX lr @ Return to caller + +@} + +/* + ************************************************************************ + * + * FUNCTION + * + * INT_Retrieve_Shell + * + * DESCRIPTION + * + * This function retrieves the pointer to the shell interrupt + * service routine. The shell interrupt service routine calls + * the LISR dispatch routine. + * + * + * Major Revision: + * + * M. Kyle Craig, Accelerated Technology, Inc. + * + * + * + * CALLED BY + * + * TCC_Register_LISR Register LISR for vector + * + * CALLS + * + * None + * + * INPUTS + * + * vector Vector number to setup + * + * OUTPUTS + * + * shell pointer + * + * HISTORY + * + * NAME DATE REMARKS + * + * W. Lamie 08-27-1994 Created initial version 1.0 + * D. Lamie 08-27-1994 Verified version 1.0 + * + ************************************************************************ + */ + +@VOID *INT_Retrieve_Shell(INT vector) +@{ + + .globl INT_Retrieve_Shell +INT_Retrieve_Shell: + + @ Return the LISR Shell interrupt routine. + @ return(INT_Vectors[vector]); + + LDR r1, =INT_IRQ_Vectors @ Load the vector table address + MOV r0, r0, LSL #2 @ Multiply vector by 4 to get offset into table + LDR r0, [r1,r0] @ Load interrupt handler pointer into return register + + BX lr @ Return to caller + + +@} + +/* + ************************************************************************ + * + * FUNCTION + * + * _INT_IRQ + * + * DESCRIPTION + * + * This routine is the board-specific section for + * level 1 interrupt handling + * + * CALLED BY + * + * None + * + * CALLS + * + * TMT_Timer_Interrupt + * + * INPUTS + * + * None + * + * + * OUTPUTS + * + * None + * + * HISTORY + * + * NAME DATE REMARKS + * + * B. Ronquillo 05-10-00 Created initial version 1.0 + * + ************************************************************************ + */ + + .globl _INT_IRQ +_INT_IRQ: + + STMDB sp!,{r0-r4} @ Save r0-r4 on temporary IRQ stack + SUB lr,lr,#4 @ Adjust IRQ return address + +/* + ******************************** + * Begin Hardware Specific Code * + ******************************** + */ + + LDR r3, =INTH_BASE_ADDR @ load Interrupt Control Base + @ Get enable register value + @ original instr was: LDR r4, [r3,#INT_CNTRL_MIR] + @ but on the Calypso we have to read two 16-bit regs + ldrh r0, [r3, #MASK_IT_REG1] + ldrh r1, [r3, #MASK_IT_REG2] + @ now combine them into a 32-bit word in r4 for the old code to work as-is + orr r4, r0, r1, lsl #16 + +/* + ****************************** + * End Hardware Specific Code * + ****************************** + */ + + STMDB sp!,{r4} @ Put the enable register value on the IRQ stack + MVN r4,#0 @ Start with 0xFFFFFFFF to allow nesting of interrupts + +/* + ******************************** + * Begin Hardware Specific Code * + ******************************** + */ + + @ Read Pending reg + @ original instr was: LDR r2, [r3,#INT_CNTRL_ITR] + @ do the same trick as we did for the mask regs + ldrh r0, [r3, #IT_REG1] + ldrh r1, [r3, #IT_REG2] + orr r2, r0, r1, lsl #16 + +/* + ****************************** + * End Hardware Specific Code * + ****************************** + */ + + LDR r3, =INT_IRQ_Priority @ Get the Priority table address + +IRQ_VECTOR_LOOP: + LDR r0, [r3,#0] @ Load first vector to be checked from priority table + MOV r1, #1 @ Build mask + MOV r1, r1, LSL r0 @ Use vector number to set mask to correct bit position + TST r1, r2 @ Test if pending bit is set + BNE IRQ_VECTOR_FOUND @ If bit is set, branch to found section... + + BIC r4,r4,r1 @ Clear mask bit to keep higher priority ints active + ADD r3, r3, #4 @ Move to next word in the priority table + LDR r0, =INT_Priority_End @ Load the end address for the priority table + CMP r0, r3 @ Make sure not at the end of the table (shouldn't happen!) + BNE IRQ_VECTOR_LOOP @ Continue to loop if not at the end of the table + + @ No bits in pending register set, restore registers and exit interrupt servicing + ADD sp,sp,#4 @ Adjust sp above IRQ enable value + LDMIA sp!,{r0-r4} @ Restore r0-r4 + STMDB sp!,{lr} @ Put return address for IRQ on stack + LDMIA sp!,{pc}^ @ return to the point of the exception and restore SPSR + +IRQ_VECTOR_FOUND: + +/* + ******************************** + * Begin Hardware Specific Code * + ******************************** + */ + + LDR r3, =INTH_BASE_ADDR @ load Interrupt Control Base + + MVN r2, r1 @ Get the inverse of the interrupt vector + @ Write a zero to the interrupt being handled (IT_REGn) + cmp r0, #16 + strloh r2, [r3, #IT_REG1] + mov r2, r2, lsr #16 + strhsh r2, [r3, #IT_REG2] + + @ Read the Mask reg - just like we did before + ldrh r1, [r3, #MASK_IT_REG1] + ldrh r2, [r3, #MASK_IT_REG2] + orr r2, r1, r2, lsl #16 + @ was LDR r2, [r3,#INT_CNTRL_MIR] + + ORR r4, r2, r4 @ Turn off lower priority pending bits and currently masked bits + + @ write both mask registers + @ was STR r4, [r3,#INT_CNTRL_MIR] + strh r4, [r3, #MASK_IT_REG1] + mov r1, r4, lsr #16 + strh r1, [r3, #MASK_IT_REG2] + + MOV r1, #1 @ Clear the pending interrupt + STRH r1, [r3,#IRQ_CTRL] @ by writing a 1 to the Control Reg + +/* + ****************************** + * End Hardware Specific Code * + ****************************** + */ + + LDR r3, =INT_IRQ_Vectors @ Get IRQ vector table address + MOV r2, r0, LSL #2 @ Multiply vector by 4 to get offset into table + ADD r3, r3, r2 @ Adjust vector table address to correct offset + LDR r2, [r3,#0] @ Load branch address from vector table + + MOV PC, r2 @ Jump to correct branch location based on vector table + +@ END: INT_IRQ + +/* + ************************************************************************ + * + * FUNCTION + * + * INT_Interrupt_Shell + * + * DESCRIPTION + * + * Handles all interrupts which use NU_Register_LISR. + * + * + * CALLED BY + * + * INT_IRQ + * + * CALLS + * + * TCT_Dispatch_LISR + * TCT_Interrupt_Context_Restore + * + * INPUTS + * + * vector (register r0) + * + * OUTPUTS + * + * None + ************************************************************************ + */ + + .globl INT_Interrupt_Shell +INT_Interrupt_Shell: + + MOV r4,lr @ Put IRQ return address into r4 + + BL TCT_Interrupt_Context_Save + + BL TCC_Dispatch_LISR + + MRS r1,CPSR @ Pickup current CPSR + BIC r1,r1,#MODE_MASK @ Clear the mode bits + ORR r1,r1,#(IRQ_MODE_OR_LOCKOUT) @ Set the IRQ mode bits and Lockout interrupts + MSR CPSR,r1 @ Lockout interrupts/change to IRQ mode + +/* + ******************************** + * Begin Hardware Specific Code * + ******************************** + */ + LDMIA sp!,{r1} @ Get IRQ enable value off IRQ stack + + LDR r2, =INTH_BASE_ADDR @ Get IRQ0 base register address + @ write it into both mask regs + @was STR r1,[r2,#INT_CNTRL_MIR] + strh r1, [r2, #MASK_IT_REG1] + mov r1, r1, lsr #16 + strh r1, [r2, #MASK_IT_REG2] +/* + ****************************** + * End Hardware Specific Code * + ****************************** + */ + + MRS r1,CPSR @ Pickup current CPSR + BIC r1,r1,#MODE_MASK @ Clear the mode bits + ORR r1,r1,#SUP_MODE @ Set the SVC mode bits + MSR CPSR,r1 @ Change to SVC mode + + B TCT_Interrupt_Context_Restore + +/* + ************************************************************************ + * + * FUNCTION + * + * INT_Timer_Interrupt + * + * DESCRIPTION + * + * This routine is the board-specific section of the timer + * interrupt handling + * + * CALLED BY + * + * None + * + * CALLS + * + * TMT_Timer_Interrupt + * + * INPUTS + * + * None + * + * + * OUTPUTS + * + * None + * + * HISTORY + * + * NAME DATE REMARKS + * + * B.Ronquillo 05-10-00 Created initial version 1.0 + * + ************************************************************************ + */ + + .globl INT_Timer_Interrupt +INT_Timer_Interrupt: + +/* + ******************************** + * Begin Hardware Specific Code * + ******************************** + * Clear the pending timer interrupt + * + * This is done in the INT_IRQ function by writing a zero to the + * timer bit. + * + ****************************** + * End Hardware Specific Code * + ****************************** + */ + + MOV r4,lr @ Put IRQ return address into r4 + + BL TCT_Interrupt_Context_Save + + BL TMT_Timer_Interrupt @ Call the timer interrupt + @ processing. + + MRS r1,CPSR @ Pickup current CPSR + BIC r1,r1,#MODE_MASK @ Clear the mode bits + ORR r1,r1,#IRQ_MODE @ Set the IRQ mode bits + MSR CPSR,r1 @ Change to IRQ mode + +/* + ******************************** + * Begin Hardware Specific Code * + ******************************** + */ + LDMIA sp!,{r1} @ Get IRQ enable value off IRQ stack + + LDR r2, =INTH_BASE_ADDR @ Get IRQ0 base register address + @ write it into both mask regs + @was STR r1,[r2,#INT_CNTRL_MIR] + strh r1, [r2, #MASK_IT_REG1] + mov r1, r1, lsr #16 + strh r1, [r2, #MASK_IT_REG2] +/* + ****************************** + * End Hardware Specific Code * + ****************************** + */ + + MRS r1,CPSR @ Pickup current CPSR + BIC r1,r1,#MODE_MASK @ Clear the mode bits + ORR r1,r1,#SUP_MODE @ Set the SVC mode bits + MSR CPSR,r1 @ Change to SVC mode + + B TCT_Interrupt_Context_Restore + +@} +@ End of INT_Timer_Interrupt + +/* + * INT_Interrupt_Init function written by Michael Spacefalcon + * for the FreeNucleus Calypso port - takes the place of + * INT_Install_Vector_Table, called from INT_Initialize. + */ + + .globl INT_Interrupt_Init +INT_Interrupt_Init: + +@ first mask all interrupts in the INTH + + ldr r0, =INTH_BASE_ADDR + mvn r1, #0 + strh r1, [r0, #MASK_IT_REG1] + strh r1, [r0, #MASK_IT_REG2] + +@ now install our IRQ vector into the magic IRAM jump table slot + + ldr r0, =_INT_IRQ + mov r1, #0x800000 + str r0, [r1, #0x14] + +@ we are done! + bx lr + +/* + * Need to define an INT_Vectors_Loaded() function + * that returns 1. + */ + .globl INT_Vectors_Loaded +INT_Vectors_Loaded: + mov r0, #1 + bx lr