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/*****************************************************************************vectors.S -- mcf52xx exception vectors*****************************************************************************/#####ECOSGPLCOPYRIGHTBEGIN###### -------------------------------------------## This file is part of eCos, the Embedded Configurable Operating System.## Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.#### eCos is free software; you can redistribute it and/or modify it under## the terms of the GNU General Public License as published by the Free## Software Foundation; either version 2 or (at your option) any later version.#### eCos is distributed in the hope that it will be useful, but WITHOUT ANY## WARRANTY; without even the implied warranty of MERCHANTABILITY or## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License## for more details.#### You should have received a copy of the GNU General Public License along## with eCos; if not, write to the Free Software Foundation, Inc.,## 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.#### As a special exception, if other files instantiate templates or use macros## or inline functions from this file, or you compile this file and link it## with other works to produce a work based on this file, this file does not## by itself cause the resulting work to be covered by the GNU General Public## License. However the source code for this file must still be made available## in accordance with section (3) of the GNU General Public License.#### This exception does not invalidate any other reasons why a work based on## this file might be covered by the GNU General Public License.#### Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.## at http://sources.redhat.com/ecos/ecos-license/## -------------------------------------------#####ECOSGPLCOPYRIGHTEND######=============================================================================#include <pkgconf/system.h>#include <pkgconf/hal.h>#ifdef CYGPKG_KERNEL#include <pkgconf/kernel.h>#endif /* CYGPKG_KERNEL *//****************************************************************************/.file "vectors.S"/****************************************************************************//****************************************************************************//* The mcf52xx core allows us to move the VBR to our RAM vector table *//* at cyg_hal_vsr_table provided the table is at a 1MB boundary. *//****************************************************************************//* ROM vector table *//* Create the ROM vector table. We use this table to initialize *//* cyg_hal_vsr_table which we point the VBR to. */.macro hw_vsr name.long hw_vsr_\name.endm.section ".romvec","ax".globl rom_vsr_tablerom_vsr_table:/* 0 - Initial SSP */hw_vsr stack/* 1 - Initial PC */hw_vsr reset/* 2-24 - Default exception handlers */.rept 24-2+1hw_vsr default.endr/* 25-31 - Autovector interrupts 1-7 */.rept 31-25+1hw_vsr autovec.endr/* 32-63 - Default exception handlers */.rept 63-32+1hw_vsr default.endr/* 64-255 - User interrupt vectors */.rept 255-64+1hw_vsr interrupt.endr.equ rom_vsr_table_size, . - rom_vsr_table/****************************************************************************//* The default excetpion vector handler *//* The default handler for all machine exceptions. We save the *//* machine state and call the default C VSR handler. This routine passes a *//* pointer to the saved state to the C VSR handler. The stack pointer in *//* the saved state points to the byte following the PC on the exception *//* stack (the sp before the exception). The format/vector word in the *//* exception stack contains the vector number. *//*void hal_default_exception_handler(CYG_WORD vector, HAL_SavedRegisters *regs);*/.text.balign 4hw_vsr_default:lea.l -(16*4)(%sp),%sp /* Preserve the entire state. */movem.l %d0-%d7/%a0-%a6,(%sp) /* Allocate space for all */lea.l ((16+1+1)*4)(%sp),%a0 /* registers (including the */move.l %a0,(15*4)(%sp) /* stack pointer). Write all *//* registers to the stack *//* space. Write the original *//* stack pointer value to the *//* stack. The format/vector *//* word, sr, and pc are already *//* on the stack. */move.w (16*4)(%sp),%d0 /* Calculate the vector */and.l #0x000003fc,%d0 /* number. The format/vector */lsr.l #2,%d0 /* word on the stack contains *//* the vector number. */pea.l (%sp) /* Pass a pointer to the *//* saved state to the exception *//* handler. */move.l %d0,-(%sp) /* Push the vector number *//* parameter. */.extern hal_default_exception_handler /* Call the default */jbsr hal_default_exception_handler /* exception VSR. This *//* routine may (and *//* probably will) modify *//* the exception context. */addq.l #2*4,%sp /* Remove the vector number *//* and the state pointer from *//* the stack. *//* Restore the state. There *//* is a chance that a debugger *//* changed the state (including *//* the stack pointer, PC, *//* etc.). We must be very *//* careful to restore the new *//* state without first *//* overwriting the values on *//* the stack. We must copy the *//* format/vector word, SR, and *//* PC to the new stack, but we *//* must make sure that the new *//* stack is not in the middle *//* of our current stack *//* variables that we are using. */movem.l (%sp),%d0-%d7/%a0-%a4 /* Restore all of the *//* registers that we do not *//* need in the following code. *//* We will copy all registers *//* that are not restored here *//* to the new stack before *//* restoring them. */move.l (15*4)(%sp),%a6 /* Load the address of the *//* new SP. */lea.l (18*4)(%sp),%a5 /* Get a pointer to the *//* location following the *//* exception context. */cmp.l %a5,%a6 /* Compare the new stack */jcc 1f /*jcc=jhs*/ /* address to the end of the *//* exception context. This *//* will tell us the order that *//* we need to copy the *//* exception stack and the *//* remaining registers from the *//* exception context to the new *//* stack. The order is *//* important because the stack *//* frames might (and in many *//* cases do) overlap. *//* The new SP is at a lower *//* address than the end of the *//* exception context. Copy *//* from the lowest address to *//* the highest address. */lea.l -5*4(%a6),%a6 /* Copy A5, A6, FVW, SR, and */move.l -5*4(%a5),(%a6) /* PC from the old stack to the */move.l -4*4(%a5),1*4(%a6) /* new stack. Note that we do */move.l -2*4(%a5),3*4(%a6) /* not copy the SP location but */move.l -1*4(%a5),4*4(%a6) /* we leave a space for it on *//* the new stack. If we do not *//* leave space for the SP, *//* there is a possibility of *//* overwriting some of our *//* data. Note that we copy in *//* increasing order. */move.l %a6,%sp /* A6 points to the top of */move.l (%sp)+,%a5 /* the new stack with our */move.l (%sp)+,%a6 /* registers on it. Restore */addq.l #1*4,%sp /* the remaining registers and */rte /* use the exception stack to *//* return. Note that we also *//* remove the unused space left *//* for the SP. */1:move.l -(%a5),-(%a6) /* The new SP is at a higher */move.l -(%a5),-(%a6) /* or the same address as the */subq.l #4,%a5 /* end of the exception */move.l -(%a5),-(%a6) /* context. Copy from the */move.l -(%a5),-(%a6) /* highest address to the *//* lowest address. Note that *//* we do not copy the stack *//* pointer. When copying in *//* this direction, there is no *//* reason to leave space for *//* the stack pointer. */move.l %a6,%sp /* A6 points to the top of */move.l (%sp)+,%a5 /* the new stack with our */move.l (%sp)+,%a6 /* registers on it. Restore */rte /* the remaining registers and *//* use the exception stack to *//* return. *//****************************************************************************//* User interrupt vector handler *//* Control is transferred here from a user interrupt vector (#64-255). *//* Before branching to common code, load a value to translate the *//* vector table offset to the ISR table offset. The ISR vector table *//* contains the autovectors (0-6) followed by the interrupt vectors *//* (7-198). */.equ int_pres_regs_sz,((2+3)*4).macro int_pres_regslea.l -int_pres_regs_sz(%sp),%spmovem.l %d0-%d2/%a0-%a1,(%sp).endm.macro int_rest_regsmovem.l (%sp),%d0-%d2/%a0-%a1lea.l int_pres_regs_sz(%sp),%sp.endm.text.balign 4hw_vsr_interrupt:int_pres_regs /* Preserve all registers *//* that this ISR routine needs *//* to preserve. The C code *//* will preserve all other *//* registers. */move.l #(-64+7)*4,%d0 /* Adding this value to the *//* vector table offset will *//* result in the corresponding *//* offset into the ISR table. *//* Fall through to common code. */hw_vsr_int_common: /* Common code. *//* d0.l: Contains a value to translate the vector table offset to *//* the ISR table offset. */move.w int_pres_regs_sz(%sp),%d1 /* Calculate the vector */and.l #0x000003fc,%d1 /* offset. The format/vector *//* word on the stack contains *//* the vector number. Mask off *//* all unused bits. The bit *//* position of the vector *//* number field makes it *//* automatically multiplied by *//* four. */add.l %d1,%d0 /* Calculate the ISR table *//* offset. Add the vector *//* table offset to the *//* translation value. */asr.l #2,%d1 /* Calculate the vector *//* number using the vector *//* table offset. *//* d0.l: Contains the offset into the ISR table. *//* d1.l: Contains the vector number. */#ifdef CYGFUN_HAL_COMMON_KERNEL_SUPPORT.extern cyg_scheduler_sched_lock /* Lock the scheduler if */addq.l #1,cyg_scheduler_sched_lock /* we are using the kernel. */#endif /* CYGFUN_HAL_COMMON_KERNEL_SUPPORT *//* We need to call the following routines. The isr address, data, and *//* intr are all from the ISR table. interrupt_end is a C routine and is *//* only called if we are using the kernel. regs points to the saved *//* registers on the stack. isr_ret is the return address from isr. vector *//* is the vector number. *//*static cyg_uint32 isr(CYG_ADDRWORD vector,CYG_ADDRWORD data)externC void interrupt_end(cyg_uint32 isr_ret,Cyg_Interrupt *intr,HAL_SavedRegisters *regs)*/pea (%sp) /* Push the regs pointer. */.extern cyg_hal_interrupt_objects /* Push the intr object */lea cyg_hal_interrupt_objects,%a0 /* pointer from the table. */move.l (%a0,%d0.l),-(%sp).extern cyg_hal_interrupt_data /* Push the data value */lea cyg_hal_interrupt_data,%a0 /* from the table. */move.l (%a0,%d0.l),-(%sp).extern cyg_hal_interrupt_handlers /* Get the address of the */lea cyg_hal_interrupt_handlers,%a0 /* ISR from the table. */move.l (%a0,%d0.l),%a0move.l %d1,-(%sp) /* Push the vector number *//* parameter. */jbsr (%a0) /* Call the ISR. */addq.l #4*1,%sp /* Remove the vector *//* parameter from the stack. */move.l %d0,(%sp) /* d0.l contains the return *//* value from the ISR. *//* Overwrite the data parameter *//* with the ISR return value to *//* pass as a parameter *//* (isr_ret) to interrupt_end. *//* The intr object and regs *//* parameters are still on the *//* stack. */#ifdef CYGFUN_HAL_COMMON_KERNEL_SUPPORT/* We only need to call interrupt_end() when there is a kernel *//* present to do any tidying up. *//* The interrupt_end routine will call the DSRs and do *//* rescheduling when it decrements the scheduler lock from 1 to *//* zero. In this case, we do not want to have interrupts masked *//* while the DSRs run. Restore the interrupt mask to the value *//* prior to this interrupt. Do not completely unmask all *//* interrupts because this interrupt may be a nested interrupt. We *//* do not want to lower the interrupt mask on the lower priority *//* interrupt. */move.w (4*3)+int_pres_regs_sz+2(%sp),%d2move.w %d2,%sr/* If the interrupt mask was not previously zero, we want to make *//* sure that the DSRs to not run and no preemption occurs. Add the *//* value of the previous interrupt mask to the scheduler lock. If *//* the previous mask was zero, the scheduler lock will remain at *//* one and the interrupt end function will decrement it to zero. *//* Otherwise, we want to prevent the interrupt end function from *//* unlocking the scheduler. We do this because there is a chance *//* that someone had interrupts masked with the scheduler lock at *//* zero. If a higher priority interrupt occurs, we could be *//* running DSRs and doing preemption with the interrupts masked! */and.l #0x0700,%d2lsr.l #8,%d2add.l %d2,cyg_scheduler_sched_lock.extern interrupt_end /* Call the interrupt_end C */jbsr interrupt_end /* routine. This routine might *//* preempt the currently *//* running thread. *//* Now that interrupt end is complete, subtract the previous *//* interrupt level back out of the scheduler lock. */sub.l %d2,cyg_scheduler_sched_lock#endiflea (4*3)(%sp),%sp /* Remove the isr_ret, intr, *//* and regs parameters from the *//* stack. */int_rest_regs /* Restore the preserved *//* registers for the current *//* thread. */rte /* Restore the SR and PC. *//****************************************************************************//* Autovector interrupt vector handler. *//* Control is transferred here from an interrupt autovector (#25-31). *//* Before branching to common code, load a value to translate the *//* vector table offset to the ISR table offset. The ISR vector table *//* contains the autovectors (0-6) followed by the interrupt vectors *//* (7-198). */.text.balign 4hw_vsr_autovec:int_pres_regs /* Preserve all registers *//* that this ISR routine needs *//* to preserve. The C code *//* will preserve all other *//* registers. */move.l #(-25+0)*4,%d0 /* Adding this value to the *//* vector table offset will *//* result in the corresponding *//* offset into the ISR table. */jra hw_vsr_int_common /* Branch into common code. *//****************************************************************************//* hw_vsr_reset -- Hardware Reset Vector *//* We assume that most of the chip selects are configured by the boot *//* loader. */.text.balign 4.globl hw_vsr_resethw_vsr_reset:.globl __exception_reset /* Define the entry point for */__exception_reset: /* the linker. */move.w #0x2700,%sr /* Make sure that all *//* interrupts are masked. */lea hw_vsr_stack,%sp /* Load the reset and *//* interrupt stack pointer. */lea 0,%fp /* Set up the initial frame */link %fp,#0 /* pointer. */.extern hal_reset /* Call the C routine to */jbsr hal_reset /* complete the reset process. */9: stop #0x2000 /* If we return, stop. */jra 9b/****************************************************************************//* Interrupt and reset stack *//* WARNING: Do not put this in any memory section that gets *//* initialized. Doing so may cause the C code to initialize its own stack. */.section ".uninvar","aw",@nobits.balign 16.global hw_vsr_stack_bottomhw_vsr_stack_bottom:.skip 0x2000.balign 16.global hw_vsr_stackhw_vsr_stack:.skip 0x10/****************************************************************************/
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