Mercurial > ecos-v3_0-branch
view packages/hal/mips/arch/current/src/vectors.S @ 126:518f42066aba ecos-sw-2000-09-19
Merge from eCos master repository on 2000-09-19-06:25:26-BST
| author | jlarmour |
|---|---|
| date | Tue, 19 Sep 2000 05:53:51 +0000 |
| parents | 6ed91473a1cd |
| children | 25e238959bae |
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##============================================================================= ## ## vectors.S ## ## MIPS exception vectors ## ##============================================================================= #####COPYRIGHTBEGIN#### # # ------------------------------------------- # The contents of this file are subject to the Red Hat eCos Public License # Version 1.1 (the "License"); you may not use this file except in # compliance with the License. You may obtain a copy of the License at # http://www.redhat.com/ # # Software distributed under the License is distributed on an "AS IS" # basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the # License for the specific language governing rights and limitations under # the License. # # The Original Code is eCos - Embedded Configurable Operating System, # released September 30, 1998. # # The Initial Developer of the Original Code is Red Hat. # Portions created by Red Hat are # Copyright (C) 1998, 1999, 2000 Red Hat, Inc. # All Rights Reserved. # ------------------------------------------- # #####COPYRIGHTEND#### ##============================================================================= #######DESCRIPTIONBEGIN#### ## ## Author(s): nickg ## Contributors: nickg, dmoseley ## Date: 1998-02-04 ## Purpose: MIPS exception vectors ## Description: This file defines the code placed into the exception ## vectors. It also contains the first level default VSRs ## that save and restore state for both exceptions and ## interrupts. ## ######DESCRIPTIONEND#### ## ##============================================================================= #include <pkgconf/system.h> #include <pkgconf/hal.h> #ifdef CYGPKG_KERNEL # include <pkgconf/kernel.h> #endif #include <cyg/hal/arch.inc> #include <cyg/hal/hal_arch.h> #ifdef at #undef at #endif .extern cyg_instrument ##----------------------------------------------------------------------------- ## Hardware supplied vectors .set noreorder .section ".reset_vector","ax" # Reset vector at 0xBFC00000 FUNC_START(reset_vector) #ifndef CYG_HAL_STARTUP_RAM # if defined(CYGPKG_HAL_RESET_VECTOR_FIRST_CODE) hal_reset_vector_first_code # endif # if defined(CYGPKG_HAL_EARLY_INIT) hal_early_init # endif # Decide whether this is an NMI, cold or warm boot. mfc0 k0,status # get status reg lui k1,0x0008 # isolate NMI bit and k1,k1,k0 beqz k1,1f # skip if zero nop lar k1,__nmi_entry # jump to ROM nmi code jalr k1 nop 1: lui k1,0x0010 # isolate soft reset bit and k1,k1,k0 beqz k1,2f # skip if zero nop lar k1,__warm_start # jump to ROM warm_start code jr k1 nop 2: la k0,INITIAL_CONFIG0 # Set up config0 register mtc0 k0,config0 # to disable cache #endif lar v0,_start # jump to start #ifdef CYGARC_START_FUNC_UNCACHED CYGARC_ADDRESS_REG_UNCACHED(v0) #endif jr v0 nop # (delay slot) FUNC_END(reset_vector) .section ".debug_vector","ax" # Debug vector at 0xBFC00200 FUNC_START(debug_vector) la k0,32*4 la k1,hal_vsr_table # Get VSR table lw k1,32*4(k1) # load debug vector jr k1 # go there nop # (delay slot) FUNC_END(debug_vector) .section ".other_vector","ax" # Common vector at 0x80000080 or 0xBFC00180 FUNC_START(other_vector) mfc0 k0,cause # K0 = exception cause nop andi k0,k0,0x7F # isolate exception code la k1,hal_vsr_table # address of VSR table add k1,k1,k0 # offset of VSR entry lw k1,0(k1) # k1 = pointer to VSR jr k1 # go there nop # (delay slot) FUNC_END(other_vector) .section ".utlb_vector","ax" FUNC_START(utlb_vector) mfc0 k0,cause # K0 = exception cause nop andi k0,k0,0x7F # isolate exception code la k1,hal_vsr_table # address of VSR table add k1,k1,k0 # offset of VSR entry lw k1,0(k1) # k1 = pointer to VSR jr k1 # go there nop # (delay slot) FUNC_END(utlb_vector) ##----------------------------------------------------------------------------- ## Startup code .text FUNC_START(_start) # Initialize hardware hal_cpu_init hal_diag_init hal_mmu_init hal_fpu_init hal_memc_init hal_intc_init hal_cache_init hal_timer_init # Load Global Pointer register. la gp,_gp # load initial stack pointer la a0,__interrupt_stack move sp,a0 hal_mon_init #ifdef CYG_HAL_STARTUP_ROM # Copy data from ROM to RAM .extern hal_copy_data jal hal_copy_data nop #endif # Zero BSS .extern hal_zero_bss jal hal_zero_bss nop # Call variant and platform HAL # initialization routines. .extern hal_variant_init jal hal_variant_init nop .extern hal_platform_init jal hal_platform_init nop # Call constructors .extern cyg_hal_invoke_constructors jal cyg_hal_invoke_constructors nop #if defined(CYGDBG_HAL_DEBUG_GDB_INCLUDE_STUBS) .extern initialize_stub jal initialize_stub nop #endif #if defined(CYGDBG_HAL_MIPS_DEBUG_GDB_CTRLC_SUPPORT) .extern hal_ctrlc_isr_init jal hal_ctrlc_isr_init nop #endif # Call cyg_start .extern cyg_start j cyg_start lui ra,0 FUNC_END(_start ) ##----------------------------------------------------------------------------- FUNC_START(__warm_start) ## The following is debug code left in here for now in case it ## proves useful in the near future. #if 0 move s0,t0 move s1,a1 # hal_diag_init hal_diag_writec '$' mfc0 a0,$30 # get ErrorEPC lar k0,hal_diag_ai_write_hex8 jalr k0 nop hal_diag_writec '-' move a0,s0 jalr k0 nop hal_diag_writec '-' move a0,s1 jalr k0 nop 1: b 1b nop #endif # Treat a warm-start either as a cold-start or an NMI #if defined(CYGHWR_HAL_MIPS_WARMSTART_COLDSTART) lar v0,_start # jump to start jr v0 nop # (delay slot) #else # Defaults to NMI b __nmi_entry nop #endif FUNC_END(__warm_start) ##----------------------------------------------------------------------------- FUNC_START(__nmi_entry) # Clear exception state hal_cpu_except_enable # Move the ErrorEPC register to the EPC register so that the # default exception handler saves the right PC value. mfc0 k0,$30 nop; nop; nop; mtc0 k0,epc nop; nop; nop; #if (INITIAL_SR & 0x00400000) == 0 # Taking this exception will have set the BEV bit to 1. # If we normally run with it zero, we must clear it here. mfc0 k0,status la k1,0xFFBFFFFF and k0,k0,k1 mtc0 k0,status #endif la k0,34*4 la k1,hal_vsr_table # Get VSR table lw k1,34*4(k1) # load NMI vector jr k1 # go there nop # (delay slot) FUNC_END(__nmi_entry) ##----------------------------------------------------------------------------- ## Default exception VSR. ## Saves machine state and calls external handling code. FUNC_START(__default_exception_vsr) # We enter here with all of the CPU state still # in its registers except: # K0 = vector index # K1 = address of this function move k1,sp # K1 = original SP #ifdef CYGSEM_HAL_ROM_MONITOR # Switch to interrupt stack to handle exception la sp,__interrupt_stack #endif addi sp,sp,-mips_exception_decrement # space for registers + safety margin sw k0,mipsreg_vector(sp) # store vector # store GPRs .set noat sgpr 0,sp sgpr 1,sp sgpr 2,sp sgpr 3,sp sgpr 4,sp sgpr 5,sp sgpr 6,sp sgpr 7,sp sgpr 8,sp sgpr 9,sp sgpr 10,sp sgpr 11,sp sgpr 12,sp sgpr 13,sp sgpr 14,sp sgpr 15,sp sgpr 16,sp sgpr 17,sp sgpr 18,sp sgpr 19,sp sgpr 20,sp sgpr 21,sp sgpr 22,sp sgpr 23,sp sgpr 24,sp sgpr 25,sp # sgpr 26,sp # == K0 # sgpr 27,sp # == K1 sgpr 28,sp # == GP # sgpr 29,sp # == SP sgpr 30,sp # == FP sgpr 31,sp # == RA .set at mfhi a0 mflo a1 shi a0,sp slo a1,sp # K1 contains original SP ssp k1,sp # store in reg dump # save remaining machine state registers mfc0 t0,cause mfc0 t1,status mfc0 t2,cachectrl mfc0 t3,badvr mfc0 t4,config mfc0 t5,prid mfc0 t6,epc sw t0,mipsreg_cause(sp) sw t1,mipsreg_sr(sp) sw t2,mipsreg_cachectrl(sp) sw t3,mipsreg_badvr(sp) sw t4,mipsreg_config(sp) sw t5,mipsreg_prid(sp) sw t6,mipsreg_pc(sp) hal_fpu_save sp # The machine state is now all saved on the stack. hal_diag_excpt_start # Load Global Pointer register. la gp,_gp move s0,sp # save pointer to saved state addi sp,sp,-mips_stack_frame_size # make a null frame # Need to set up back pointers etc. ??? la ra,restore_state # load return address hal_cpu_except_enable # reenable exceptions .extern cyg_hal_exception_handler j cyg_hal_exception_handler # call C code move a0,s0 # arg0 = register dump (delay slot) # When the exception handler returns, it will # go back to restore_state, below. FUNC_END(__default_exception_vsr) ##------------------------------------------------------------------------------ ## Default interrupt VSR. ## Saves machine state and calls appropriate ISR. When done, calls ## interrupt_end() to finish up and possibly reschedule. FUNC_START(__default_interrupt_vsr) # We enter here with all of the CPU state still # in its registers except: # K0 = vector index # K1 = address of this function move k1,sp # K1 = original SP addi sp,sp,-mips_exception_decrement # space for registers + safety margin sw k0,mipsreg_vector(sp) # store vector # store GPRs .set noat sgpr 0,sp sgpr 1,sp sgpr 2,sp sgpr 3,sp sgpr 4,sp sgpr 5,sp sgpr 6,sp sgpr 7,sp sgpr 8,sp sgpr 9,sp sgpr 10,sp sgpr 11,sp sgpr 12,sp sgpr 13,sp sgpr 14,sp sgpr 15,sp sgpr 16,sp sgpr 17,sp sgpr 18,sp sgpr 19,sp sgpr 20,sp sgpr 21,sp sgpr 22,sp sgpr 23,sp sgpr 24,sp sgpr 25,sp # sgpr 26,sp # == K0 # sgpr 27,sp # == K1 sgpr 28,sp # == GP # sgpr 29,sp # == SP sgpr 30,sp # == FP sgpr 31,sp # == RA .set at mfhi a0 mflo a1 shi a0,sp slo a1,sp # K1 contains original SP ssp k1,sp # store in reg dump mfc0 t1,status mfc0 t2,cachectrl mfc0 t3,epc sw t1,mipsreg_sr(sp) sw t2,mipsreg_cachectrl(sp) sw t3,mipsreg_pc(sp) hal_fpu_save sp # The machine state is now all saved on the stack. # Load Global Pointer register. la gp,_gp #ifdef CYGFUN_HAL_COMMON_KERNEL_SUPPORT .extern cyg_scheduler_sched_lock la v0,cyg_scheduler_sched_lock lw a0,0(v0) addi a0,a0,1 sw a0,0(v0) #endif move s0,sp # save pointer to saved state #ifdef CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK la a0,__interrupt_stack # a0 = stack top la a1,__interrupt_stack_base # a1 = stack base sub a3,sp,a1 # a3 = sp - base bltz a3,1f # if < 0 - not on istack nop # delay slot sub t0,a0,sp # t0 = top - sp bgtz t0,8f # if > 0 - already on istack nop # delay slot 1: move sp,a0 # switch to istack 8: addi sp,sp,-8 # space for old SP # (8 to keep dword alignment!) sw s0,0(sp) # save old SP on stack #endif subu sp,sp,mips_stack_frame_size # make a null frame # Need to set up back pointers etc. ??? # Decode external interrupt via interrupt controller hal_intc_decode s2 # Here, s2 contains the number of the interrupt being serviced, # we need to derive from that the vector number to call in the ISR # table. hal_intc_translate s2,s1 # Here s1 is the number of the vector to be called and s2 is # the number of the interrupt being serviced. hal_diag_intr_start #if defined(CYGPKG_KERNEL_INSTRUMENT) && defined(CYGDBG_KERNEL_INSTRUMENT_INTR) # Call cyg_instrument to record that this interrupt is being raised. li a0,0x0301 # a0 = type = INTR,RAISE move a1,s1 # a1 = vector number jal cyg_instrument # call instrument function move a2,s2 # a2 = interrupt number #endif #if defined(CYGDBG_HAL_MIPS_DEBUG_GDB_CTRLC_SUPPORT) # If we are supporting Ctrl-C interrupts from GDB, we must squirrel # away a pointer to the save interrupt state here so that we can # plant a breakpoint at some later time. .extern hal_saved_interrupt_state la v0,hal_saved_interrupt_state sw s0,0(v0) #endif sll s1,s1,2 # s1 = byte offset of vector hal_cpu_except_enable # reenable exceptions la t2,hal_interrupt_handlers # handler table add t2,t2,s1 # address of ISR ptr lw t2,0(t2) # ISR pointer la a1,hal_interrupt_data # data table add a1,a1,s1 # address of data ptr lw a1,0(a1) # Data pointer move a0,s2 # pass interrupt number jalr t2 # call ISR via t2 nop # (delay slot) #ifdef CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK # If we are returning from the last nested interrupt, move back # to the thread stack. interrupt_end() must be called on the # thread stack since it potentially causes a context switch. # Since we have arranged for the top of stack location to # contain the sp we need to go back to here, just pop it off # and put it in SP. lw sp,mips_stack_frame_size(sp) # sp = *sp subu sp,sp,mips_stack_frame_size # make a null frame #endif #ifdef CYGFUN_HAL_COMMON_KERNEL_SUPPORT # We only need to call _interrupt_end() when there is a kernel # present to do any tidying up. # On return v0 bit 1 will indicate whether a DSR is # to be posted. Pass this together with a pointer to # the interrupt object we have just used to the # interrupt tidy up routine. # Note that s0, s1 and s2 are defined to be preserved across # calls by the calling convention, so they still contain # the register dump, the vector offset and the interrupt number # respectively. move s2,v0 la a1,hal_interrupt_objects # interrupt object table add a1,a1,s1 # address of object ptr lw a1,0(a1) # a1 = object ptr move a2,s0 # arg3 = saved register dump .extern interrupt_end jal interrupt_end # call into C to finish off move a0,v0 # put ISR result in arg0 move v0,s2 # return value from isr #endif restore_state: #if defined(CYGSEM_HAL_USE_ROM_MONITOR_CygMon) move k0,v0 #endif # All done, restore CPU state and continue addi sp,sp,mips_stack_frame_size # retrieve CPU state ptr # Disable interrupts again while we restore state. hal_cpu_int_disable hal_diag_restore hal_fpu_load sp lw t0,mipsreg_cachectrl(sp) lhi t1,sp llo t2,sp mtc0 t0,cachectrl mthi t1 mtlo t2 # load GPRs .set noat # lgpr 0,sp lgpr 1,sp lgpr 2,sp lgpr 3,sp lgpr 4,sp lgpr 5,sp lgpr 6,sp lgpr 7,sp lgpr 8,sp lgpr 9,sp lgpr 10,sp lgpr 11,sp lgpr 12,sp lgpr 13,sp lgpr 14,sp lgpr 15,sp lgpr 16,sp lgpr 17,sp lgpr 18,sp lgpr 19,sp lgpr 20,sp lgpr 21,sp lgpr 22,sp lgpr 23,sp lgpr 24,sp lgpr 25,sp # lgpr 26,sp # == K0 # lgpr 27,sp # == K1 lgpr 28,sp # == GP # lgpr 29,sp # == SP lgpr 30,sp # == FP lgpr 31,sp # == RA .set at #if defined(CYGSEM_HAL_USE_ROM_MONITOR_CygMon) # If we have a Cygmon that wants to listen to network interrupts, then # the return code from the earlier call to hal_default_isr() will # have been negative to indicate this. So we jump into Cygmon here # because Cygmon requires the processor state to be the same as when # the interrupt was taken, but with k0 as the exception number. bgez k0,1f nop # Check for new cygmon sw k0,(mipsreg_regs+26*4)(sp) # save k0 la k1,0x80000100 + 41*4 # New cygmon "magic" id lw k1,0(k1) lui k0,0x55aa ori k0,0x4321 bne k0,k1,1f # Need to let cygmon handle this la k1,0x80000100 + 39*4 # stub entry vector lw k0,(mipsreg_regs+26*4)(sp) # restore k0 lw k1,0(k1) lw sp,(mipsreg_regs+29*4)(sp) # restore SP sll k0,1 # clear bit 31. jr k1 srl k0,1 1: #endif lw k0,mipsreg_pc(sp) # K0 = return PC lw k1,mipsreg_sr(sp) # K1 = saved SR lsp sp,sp # load SP # Invoke CPU specific mechanism for returning from this # exception hal_cpu_eret k0,k1 FUNC_END(__default_interrupt_vsr) hal_intc_decode_data ##----------------------------------------------------------------------------- ## Execute pending DSRs on the interrupt stack with interrupts enabled. ## Note: this can only be called from code running on a thread stack #ifdef CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK .extern cyg_interrupt_call_pending_DSRs FUNC_START(hal_interrupt_stack_call_pending_DSRs) mfc0 t0,status # get status register value la v0,__interrupt_stack # v0 = interrupt stack move v1,sp # v1 = original stack ptr move sp,v0 # sp = interrupt stack addi sp,sp,-32 # make a null frame sw v1,16(sp) # save old sp sw ra,20(sp) # save old ra sw t0,24(sp) # save old sr hal_cpu_int_enable jal cyg_interrupt_call_pending_DSRs # call back to kernel nop lw a0,24(sp) # get status reg hal_cpu_int_merge a0 # merge with current SR lw ra,20(sp) # restore ra lw sp,16(sp) # restore sp jr ra # go back nop # delay slot FUNC_END(hal_interrupt_stack_call_pending_DSRs) #endif ##----------------------------------------------------------------------------- ## Short circuit in case any code tries to use "__gccmain()" FUNC_START(__gccmain) jr ra nop FUNC_END(__gccmain) ##----------------------------------------------------------------------------- ## VSR springboard for break instruction exceptions ## Both GCC and GDB use break instructions. GCC for division-by-zero ## notification and GDB for program-flow breakpoints. This springboard ## looks for the d-b-z kind and directs them to another vector so libc ## can handle these without affecting the debugger. FUNC_START(__break_vsr_springboard) mfc0 k0,epc mfc0 k1,cause bltzl k1,1f addi k0,k0,4 # delay slot (only executed if BD set) 1: lw k1,0(k0) # get break instruction la k0,0x0007000d # break 0x7 used by GCC for d-b-z bne k0,k1,2f nop ori k0,$0,14*4 # CYGNUM_HAL_VECTOR_DIV_BY_ZERO la k1,hal_vsr_table # address of VSR table add k1,k1,k0 # offset of VSR entry lw k1,0(k1) # k1 = pointer to VSR jr k1 # go there nop # (delay slot) 2: ori k0,$0,9*4 # CYGNUM_HAL_VECTOR_BREAKPOINT j __default_exception_vsr nop # (delay slot) FUNC_END(__break_vsr_springboard) ##----------------------------------------------------------------------------- ## Interrupt Stack. ## Used during intialization and for executing ISRs. .bss .balign 16 .global cyg_interrupt_stack_base cyg_interrupt_stack_base: __interrupt_stack_base: .rept CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE .byte 0 .endr .balign 16 .global cyg_interrupt_stack cyg_interrupt_stack: __interrupt_stack: .long 0,0,0,0,0,0,0,0 ##----------------------------------------------------------------------------- ## VSR table. ## The main interrupt code indirects through here to find the VSR ## to execute for each architecture defined interrupt. ## This is only used for simulated targets, on real targets a fixed location VSR ## table is now allocated at 0x80000100. #ifndef CYG_HAL_MIPS_VSR_TABLE_DEFINED ## .section ".vsr_table","a" .data .globl hal_vsr_table hal_vsr_table: .long __default_interrupt_vsr .rept 63 .long __default_exception_vsr .endr #endif #------------------------------------------------------------------------------ # Interrupt vector tables. # These tables contain the isr, data and object pointers used to deliver # interrupts to user code. # hal_interrupt_level contains the interrupt level set by # HAL_INTERRUPT_CONFIGURE(). # This is a default set that provide support only for the 6 external # interrupts in the status/cause registers. Platforms or boards are expected # to define their own versions of these if they have their own interrupt mappings. #ifndef CYG_HAL_MIPS_ISR_TABLES_DEFINED .extern hal_default_isr .data .globl hal_interrupt_handlers hal_interrupt_handlers: .long hal_default_isr .long hal_default_isr .long hal_default_isr .long hal_default_isr .long hal_default_isr .long hal_default_isr .globl hal_interrupt_data hal_interrupt_data: .rept 6 .long 0 .endr .globl hal_interrupt_objects hal_interrupt_objects: .rept 6 .long 0 .endr #endif ##----------------------------------------------------------------------------- ## end of vectors.S
