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NT4/private/ntos/fw/mips/j3reset.s
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#if defined(JAZZ) && defined(R3000)
/*++
Copyright (c) 1990 Microsoft Corporation
Module Name:
j3reset.s
Abstract:
This module is the start of the boot code. This code will
be the first run upon reset. It contains the self-test and
initialization.
Author:
Lluis Abello (lluis) 8-Jan-91
Environment:
Executes in kernal mode.
Notes:
***** IMPORTANT *****
This module must be linked such that it resides in the
first page of the rom.
Revision History:
Some code is stolen from johncoop's "reset.s"
--*/
//
// include header file
//
#include "ksmips.h"
#include <jazzprom.h>
#include "selfmap.h"
#include "led.h"
#include "jzconfig.h"
#include "dmaregs.h"
#include "ioaccess.h"
#define PROM_BASE (KSEG1_BASE | 0x1fc00000)
#define PROM_ENTRY(x) (PROM_BASE + ((x) * 8))
//
// redifne bal to be a relative branch and link instead of jal as it's
// defined in kxmips.h
// The cpp will issue a redefinition warning message.
//
#define bal bgezal zero,
#define DMA_CHANNEL_GAP 0x20 // distance beetwen DMA channels
//
// create a small sdata section.
//
.sdata
.space 4
.text
.set noreorder
.set noat
.globl ResetVector
ResetVector:
/*++
Routine Description:
This routine will provide the jump vectors located
at the targets of the processor exception vectors.
This routine must be located at the start of ROM which
is the location of the reset vector.
Arguments:
None.
Return Value:
None.
--*/
//
// this instruction must be loaded at location 0 in the
// rom. This will appear as BFC00000 to the processor
//
b ResetException
nop
//
// This is the jump table for rom routines that other
// programs can call. They are placed here so that they
// will be unlikely to move.
//
//
// This becomes PROM_ENTRY(2) as defined in ntmips.h
//
.align 4
li k0,MONITOR_LINK_ADDRESS // la k0,MonitorReInit
li k1,GLOBAL_DATA_BASE
j k0
sw $31,0x7C(k1) // save return address
//
// This becomes PROM_ENTRYS(12,13)
//
.align 6
nop // entry 8
nop
nop // entry 9
nop
b TlbInit // entry 10
nop
nop // entry 11
nop
GetCharJumpInstruction:
b GetCharJumpInstruction // entry 12
nop
PutCharJumpInstruction:
b PutCharJumpInstruction // entry 13
nop
b PutLedDisplay // entry 14
nop
GetLineJumpInstruction:
b GetLineJumpInstruction // entry 15
nop
PutLineJumpInstruction:
b PutLineJumpInstruction // entry 16
nop
// .word BitMapPointers-LINK_ADDRESS+KSEG0_BASE // entry 17 address of BitmapPointers
nop_opcode: nop // nop opcode to test the icache
j ra // return opcode
//
// these next vectors should be loaded at BFC00100,BFC00180,
// They are for the TLBmiss, and
// common exceptions respectively.
//
.align 8
UserTlbMiss:
//
// checks if exception occurred in the tlbtest
//
mfc0 k1,epc // we enter this routine a
la k0,TlbTestBegin // load the start address of the
// TlbTest code likely to fail
slt k0,k1,k0 // check if exception happend
bne k0,zero,NormalException // on a smaller address
la k0,TlbTestEnd // load the end address of the
// TlbTest code likely to fail
slt k0,k0,k1 // and check if exception happend
bne k0,zero,NormalException // on a bigger address
nop
lui a1,LED_BLINK //
bal PutLedDisplay //
or a0,a1,a0 //
NormalException:
la k0,ExceptionDispatch //
mfc0 k1,cause // read cause register
j k0 // go to Dispatcher
andi k1,k1,0xFF // just execcode field from cause reg.
.align 7
mfc0 k1,cause // get cause
li k0,KSEG1_BASE //
sw k1,0(k0) // write cause reg to phys address zero
la k0,ExceptionDispatch // get address of Dispatcher
j k0 // go to dispatcher
andi k1,k1,0xFF // just execcode field from cause reg.
.align 4
ALTERNATE_ENTRY(MemoryRoutines) // The test code is copied from here to EndMemoryRoutines
// into memory to run it cached.
/*++
VOID
WriteAddressTest(
StartAddress
Size
Xor pattern
)
Routine Description:
This routine will store the address of each location xored with
the Pattern into each location.
Arguments:
a0 - supplies start of memory area to test
a1 - supplies length of memory area in bytes
a2 - supplies the pattern to Xor with.
Note: the values of the arguments are preserved.
Return Value:
This routine returns no value.
--*/
ALTERNATE_ENTRY(MemoryTest) // The monitor calls this
LEAF_ENTRY(WriteAddressTest)
add t1,a0,a1 // t1 = last address.
xor t0,a0,a2 // t0 value to write
move t2,a0 // t2=current address
writeaddress:
sw t0,0(t2) // store
addiu t2,t2,4 // compute next address
xor t0,t2,a2 // next pattern
sw t0,0(t2)
addiu t2,t2,4 // compute next address
xor t0,t2,a2 // next pattern
sw t0,0(t2)
addiu t2,t2,4 // compute next address
xor t0,t2,a2 // next pattern
sw t0,0(t2)
addiu t2,t2,4 // compute next address
bne t2,t1, writeaddress // check for end condition
xor t0,t2,a2 // value to write
j ra
nop
.end WriteAddressTest
/*++
VOID
WriteNoXorAddressTest(
StartAddress
Size
)
Routine Description:
This routine will store the address of each location
into each location.
Arguments:
a0 - supplies start of memory area to test
a1 - supplies length of memory area in bytes
Note: the values of the arguments are preserved.
Return Value:
This routine returns no value.
--*/
LEAF_ENTRY(WriteNoXorAddressTest)
add t1,a0,a1 // t1 = last address.
addiu t1,t1,-4
move t2,a0 // t2=current address
writenoXoraddress:
sw t2,0(t2) // store first address
addiu t2,t2,4 // compute next address
sw t2,0(t2) // store first address
addiu t2,t2,4 // compute next address
sw t2,0(t2) // store first address
addiu t2,t2,4 // compute next address
sw t2,0(t2) // store
bne t2,t1, writenoXoraddress // check for end condition
addiu t2,t2,4 // compute next address
j ra
nop
.end WriteNoXorAddressTest
/*++
VOID
CheckAddressTest(
StartAddress
Size
Xor pattern
LedDisplayValue
)
Routine Description:
This routine will check that each location contains it's address
xored with the Pattern as written by WriteAddressTest.
Note: the values of the arguments are preserved.
Arguments:
This routine will check that each location contains it's address
xored with the Pattern as written by WriteAddressTest. The memory
is read cached or non cached according to the address specified by a0.
Write address test writes allways KSEG1_ADR=KSEG1_ADR ^ KSEG1_XOR
if a0 is in KSEG0 to read the data cached, then the XOR_PATTERN
Must be such that:
KSEG0_ADR ^ KSEG0_XOR = KSEG1_ADR ^ KSEG1_XOR
Examples:
If XorPattern with which WriteAddressTest was called is KSEG1_PAT
and the XorPattern this routine needs is KSEG0_PAT:
KSEG1_XOR Written KSEG0_XOR So that
0x00000000 0xA0 0x20000000 0x80 ^ 0x20 = 0xA0
0xFFFFFFFF 0x5F 0xDFFFFFFF 0x80 ^ 0xDF = 0x5F
0x01010101 0xA1 0x21010101 0x80 ^ 0x21 = 0xA1
Note: the values of the arguments are preserved.
a0 - supplies start of memory area to test
a1 - supplies length of memory area in bytes
a2 - supplies the pattern to Xor with.
a3 - suplies the value to display in the led in case of failure
Return Value:
This routine returns no value.
It will hang displaying the test number if it finds an error
and not configured in loop on error.
--*/
LEAF_ENTRY(CheckAddressTest)
move t3,a0 // t3 first address.
add t2,t3,a1 // last address.
checkaddress:
lw t1,0(t3) // load from first location
xor t0,t3,a2 // first expected value
bne t1,t0,PatternFail
addiu t3,t3,4 // compute next address
lw t1,0(t3) // load from first location
xor t0,t3,a2 // first expected value
bne t1,t0,PatternFail
addiu t3,t3,4 // compute next address
lw t1,0(t3) // load from first location
xor t0,t3,a2 // first expected value
bne t1,t0,PatternFail
addiu t3,t3,4 // compute next address
lw t1,0(t3) // load from first location
xor t0,t3,a2 // first expected value
bne t1,t0,PatternFail // check last one.
addiu t3,t3,4 // compute next address
bne t3,t2, checkaddress // check for end condition
move v0,zero // set return value to zero.
j ra // return a zero to the caller
PatternFail:
//
// check if we are in loop on error
//
li t0,DIAGNOSTIC_VIRTUAL_BASE // get base address of diag register
lb t0,0(t0) // read register value.
li t1,LOOP_ON_ERROR_MASK // get value to compare
andi t0,DIAGNOSTIC_MASK // mask diagnostic bits.
li v0,PROM_ENTRY(14) // load address of PutLedDisplay
beq t1,t0,10f // brnach if loop on error.
move s8,a0 // save register a0
lui t0,LED_BLINK // get LED blink code
jal v0 // Blink LED and hang.
or a0,a3,t0 // pass a3 as argument in a0
10:
lui t0,LED_LOOP_ERROR // get LED LOOP_ERROR code
jal v0 // Set LOOP ON ERROR on LED
or a0,a3,t0 // pass a3 as argument in a0
b CheckAddressTest // Loop back to test again.
move a0,s8 // restoring arguments.
.end CheckAddressTest
/*++
VOID
CheckNoXorAddressTest(
StartAddress
Size
LedDisplayValue
)
Routine Description:
This routine will check that each location contains it's address
xored with the Pattern as written by WriteAddressTest.
Arguments:
Note: the values of the arguments are preserved.
a0 - supplies start of memory area to test
a1 - supplies length of memory area in bytes
a2 - supplies the pattern to Xor with.
a3 - suplies the value to display in the led in case of failure
Return Value:
This routine returns no value.
It will hang displaying the test number if it finds an error.
--*/
LEAF_ENTRY(CheckNoXorAddressTest)
addiu t3,a0,-4 // t3 first address-4
add t2,a0,a1 // last address.
addiu t2,t2,-8 // adjust
move t1,t3 // get copy of t3 just for first check
checkaddressNX:
bne t1,t3,PatternFailNX
lw t1,4(t3) // load from first location
addiu t3,t3,4 // compute next address
bne t1,t3,PatternFailNX
lw t1,4(t3) // load from next location
addiu t3,t3,4 // compute next address
bne t1,t3,PatternFailNX
lw t1,4(t3) // load from next location
addiu t3,t3,4 // compute next address
bne t1,t3,PatternFailNX // check
lw t1,4(t3) // load from next location
bne t3,t2, checkaddressNX // check for end condition
addiu t3,t3,4 // compute next address
bne t1,t3,PatternFailNX // check last
nop
j ra // return a zero to the caller
move v0,zero //
PatternFailNX:
//
// check if we are in loop on error
//
li t0,DIAGNOSTIC_VIRTUAL_BASE // get base address of diag register
lb t0,0(t0) // read register value.
li t1,LOOP_ON_ERROR_MASK // get value to compare
andi t0,DIAGNOSTIC_MASK // mask diagnostic bits.
li v0,PROM_ENTRY(14) // load address of PutLedDisplay
beq t1,t0,10f // brnach if loop on error.
move s8,a0 // save register a0
lui t0,LED_BLINK // get LED blink code
jal v0 // Blink LED and hang.
or a0,a3,t0 // pass a3 as argument in a0
10:
lui t0,LED_LOOP_ERROR // get LED LOOP_ERROR code
jal v0 // Set LOOP ON ERROR on LED
or a0,a3,t0 // pass a3 as argument in a0
b CheckNoXorAddressTest // Loop back to test again.
move a0,s8 // restoring arguments.
.end CheckNoXorAddressTest
.globl ResetException
ResetException:
.globl _start
_start:
/*++
Routine Description:
This is the handler for the reset exception. It first checks the cause
of the exception. If it is an NMI, then control is passed to the
exception dispatch routine. Otherwise the machine is initialized.
1. Invalidate TLB, and clear coprocessor 0 cause register
2. Map the diagnostic LED, and MCT_ADR control register, zero remaining TLB
3. Test the processor
4. Test the reset state of address chip and then initialize values.
5. Map all of rom, and begin executing code in virtual address space.
6. Perform checksum of ROM
7. Test a small portion of memory. (Test code run from ROM)
8. Test the TLB
9. Copy memory test routines to memory so they can execute faster there.
10. flush and initialize dcache.
11. Test a larger section of memory. (Test code run uncached from memory)
12. Flush and initialize icache.
13. Initialize TlbMiss handler routine.
14. Test Video Memory
15. Copy Selftest image from rom to memory, and call.
16. Copy monitor image from rom to memory, and jump.
Note:
This routine must be loaded into the first page of rom.
Any routines that are called before jumping to virtual
addresses must also be loaded into the first page of rom.
Arguments:
None.
Return Value:
None.
--*/
//
// Initialize cause and status registers.
//
li t0,(1 << PSR_BEV)
mtc0 t0,psr
mtc0 zero,cause
//
// Map the 7 segment display
//
MapDisplay:
li t0,LED_LO
li t1,LED_HI
mtc0 t0,entrylo
mtc0 t1,entryhi
mtc0 zero,index
nop
tlbwi
//
// Map also the MCTADR
//
li t0,(1<<INDEX_INDEX) // tlb index entry 1
mtc0 t0,index
li t1,DEVICE_LO //
li t2,DEVICE_HI //
mtc0 t1,entrylo
mtc0 t2,entryhi
addiu t0,t0,(1<<INDEX_INDEX) // compute next index
tlbwi
//
// Zero the remaining TLB entries.
//
li t1,64*(1<<INDEX_INDEX) // load last tlb index
mtc0 zero,entrylo // clear entrylo - Invalid entry
li t2,RESV_HI // get VPN on a reserved space
zerotlb:
mtc0 t2,entryhi // clear entryhi
mtc0 t0,index // set index
addiu t0,t0,(1<<INDEX_INDEX) // compute next index
tlbwi
bne t0,t1,zerotlb //
addiu t2,PAGE_SIZE
//
// Turn off the LED and display that Processor test is starting.
//
bal PutLedDisplay
ori a0,zero,LED_BLANK
bal PutLedDisplay
ori a0,zero,LED_PROCESSOR_TEST
//
// test the processor. Test uses all registers and almost all the instructions
//
ProcessorTest:
lui a0,0x1234 // a0=0x12340000
ori a1,a0,0x4321 // a1=0x12344321
add a2,zero,a0 // a2=0x12340000
addiu a3,zero,-0x4321 // a3=0xFFFFBCDF
subu AT,a2,a3 // AT=0x12344321
bne a1,AT,ProcessorError // branch if don't match
andi v0,a3,0xFFFF // v0=0x0000BCDF
ori v1,v0,0xFFFF // v1=0x0000FFFF
sll t0,v1,16 // t0=0xFFFF0000
xor t1,t0,v1 // t1=0xFFFFFFFF
sra t2,t0,16 // t2=0xFFFFFFFF
beq t1,t2,10f // if eq good
srl t3,t0,24 // t3=0x000000FF
j ProcessorError // if wasn't eq error.
10: sltu s0,t0,v1 // S0=0 because t0 > v1
bgtz s0,ProcessorError // if s0 > zero error
or t4,AT,v0 // t4=X
bltz s0,ProcessorError // if s0 < zero error
nor t5,v0,AT // t5=~X
and t6,t4,t5 // t6=0
bltzal t6,ProcessorError // if t6 < 0 error. Load ra in any case
nop
RaAddress:
la t7,RaAddress- LINK_ADDRESS + RESET_VECTOR // get expected address in ra
bne ra,t7,ProcessorError // error if don't mach
ori s1,zero,0x100 // load constant
mult s1,t3 // 0x100*0xFF
mfhi s3 // s3=0
mflo s2 // s2=0xFF00
blez s3,10f // branch if correct
sll s4,t3,zero // move t3 into s4
addiu s4,100 // change value in s4 to produce an error
10: divu s5,s2,s4 // divide 0xFF00/0xFF
nop
nop
mfhi s6 // remainder s6=0
bne s5,s1,ProcessorError
nop
blez s6,10f // branch if no error
nop
j ProcessorError
10: sub s7,s5,s4 // s7=1
mthi s7
mtlo AT
xori gp,s5,0x2566 // gp=0x2466
move s0,sp // save sp for now
srl sp,gp,s7 // sp=0x1233
mflo s8 // s8=0x12344321
mfhi k0 // k0=1
ori k1,zero,16 // k1=16
sra k1,s8,k1 // k1=0x1234
add AT,sp,k0 // AT=0x1234
bne k1,AT,ProcessorError // branch on error
nop
//
// Processor test passed if code gets this far
// Continuue with test of address chip.
//
b MctadrTest
//
// processor error routine
//
ProcessorError:
lui a0,LED_BLINK // blink also means that
bal PutLedDisplay // the routine hangs.
ori a0,LED_PROCESSOR_TEST // displaying this value.
/*++
VOID
PutLedDisplay(
a0 - display value.
)
Routine Description:
This routine will display in the LED the value specified as argument
a0.
This routine must reside in the first page of ROM because it is
called before mapping the rom.
Arguments:
a0 value to display.
Return Value:
None.
--*/
LEAF_ENTRY(PutLedDisplay)
li t0,DIAGNOSTIC_VIRTUAL_BASE // load address of display
LedBlinkLoop:
srl t1,a0,16 // get upper bits of a0 in t1
srl t3,a0,4 // get test number
li t4,LED_LOOP_ERROR //
bne t1,t4, DisplayTestID
andi t3,t3,0xF // clear other bits.
ori t3,t3,LED_DECIMAL_POINT // Set decimal point
DisplayTestID:
li t4,LED_BLINK // check if need to hung
beq t1,t4, ShowSubtestID
sb t3,0(t0) // write test ID to led.
j ra // return to caller.
nop
ShowSubtestID:
li t2,LED_DELAY_LOOP // get delay value.
TestWait:
bne t2,zero,TestWait // loop until zero
addiu t2,t2,-1 // decrrement counter
li t3,LED_DECIMAL_POINT+LED_BLANK //
sb t3,0(t0) // write decimal point
li t2,LED_DELAY_LOOP/2 // get delay value.
DecPointWait:
bne t2,zero,DecPointWait // loop until zero
addiu t2,t2,-1 // decrement counter
andi t3,a0,0xF // get subtest number
sb t3,0(t0) // write subtest in LED
li t2,LED_DELAY_LOOP // get delay value.
SubTestWait:
bne t2,zero,SubTestWait // loop until zero
addiu t2,t2,-1 // decrrement counter
b LedBlinkLoop // go to it again
nop
.end PutLedDisplay
/*++
VOID
ZeroMemory(
ULONG StartAddress
ULONG Size
);
Routine Description:
This routine will zero a range of memory.
Arguments:
a0 - supplies start of memory
a1 - supplies length of memory in bytes
Return Value:
None.
--*/
LEAF_ENTRY(ZeroMemory)
add a1,a1,a0 // Compute End address
addiu a1,a1,-4 //
ZeroMemoryLoop:
sw zero,0(a0) // zero memory.
bne a0,a1,ZeroMemoryLoop // loop until done.
addiu a0,a0,4
j ra // return
nop
ALTERNATE_ENTRY(ZeroMemoryEnd)
nop
.end ZeroMemory
LEAF_ENTRY(R3000CacheInit)
/*++
Routine Description:
This routine will flush the R3000 caches. This is done
by setting the isolate cache bit in the status register
and then doing partial stores to the cache.
This routine should be called with the swapcache bit set
to flush the icache.
This entire routine should run uncached.
Arguments:
None.
Return Value:
None.
--*/
//
// save status register and then
// set isolation bit. This means that operations will
// not actually go to memory.
//
mfc0 t1,psr // get psr
li t0,(1 << PSR_ISC) // set isolate cache bit
or t0,t1,t0 // or them together
mtc0 t0,psr // disable interrupts, isolate cache.
nop // wait for data cache isolation
nop
nop
nop
nop
nop
nop
nop
//
// by writing partials the caches are invalidated.
// these writes don't actually go to memory because
// cache is isolated.
// write to all cache lines.
//
li t0,KSEG0_BASE // physical address for flushing
li t4,DATA_CACHE_SIZE // load size of cache.
add t4,t0,t4 // value for end of loop condition
flushcacheloop:
sb zero,0(t0) // flush cache block
sb zero,4(t0)
sb zero,8(t0)
sb zero,12(t0)
sb zero,16(t0)
sb zero,20(t0)
sb zero,24(t0)
addu t0,t0,32 // advance flush pointer
sltu t1,t0,t4 // check if end of cache.
bne zero,t1,flushcacheloop // if ne, more to flush
sb zero,-4(t0)
nop // wait for store oper. to clear pipe
nop
nop
nop
li t0,(1 << PSR_BEV)
nop
mtc0 t0,psr // unisolate and swap caches back
nop // wait for caches to swap back
nop
nop
j ra // return.
nop
.end R3000CacheInit
LEAF_ENTRY(R3000ICacheTest)
/*++
Routine Description:
This routine will write the Icache with nops plus a return opcode
and execute them.
This entire routine should run uncached.
Arguments:
a0 - nop opcode
a1 - j ra opcode
Return Value:
None.
--*/
//
// Copy nops to memory plus a return opcode, and jump to execute them in cached
// space.
//
li t0,KSEG1_BASE+MEMTEST_SIZE // start of tested memory
li t1,INSTRUCTION_CACHE_SIZE-4 // size filled with nop opcodes
add t1,t1,t0 // last address.
WriteNop:
sw a0,0(t0) // write nop opcode
bne t0,t1,WriteNop // check if last
addiu t0,t0,4
li t1,KSEG0_BASE+MEMTEST_SIZE // address of wirtten nops in cached space
j t1 // go to execute cached
sw a1,-8(t0) // store return opcode the return
// opcode will return to the caller
// leave a nop in the delay slot
.end R3000ICacheTest
/*++
VOID
DataCopy(
ULONG SourceAddress
ULONG DestinationAddress
ULONG Length
);
Routine Description:
This routine will copy data from one location to another
Source, destination, and length must be word aligned.
Arguments:
a0 - supplies source of data
a1 - supplies destination of data
a2 - supplies length of data in bytes
Return Value:
None.
--*/
LEAF_ENTRY(DataCopy)
add a2,a2,a0 // get last address
CopyLoop:
lw t5,0(a0) // get source of data
addiu a0,a0,4 // increment source pointer
sw t5,0(a1) // put to dest.
bne a0,a2,CopyLoop // loop until address=last address
addiu a1,a1,4 // increment destination pointer
j ra // return
nop
ALTERNATE_ENTRY(EndMemoryRoutines)
nop
.end DataCopy
//++
//
// VOID
// FlushWriteBuffer (
// VOID
// )
//
// Routine Description:
//
// This function flushes the write buffer on the current processor.
// this routine does the same that NtFlushWriteBuffer except that it
// doesn't return any value. It's intended to be called just
// from this module.
//
// It must reside in the first page of the ROM.
//
// Arguments:
//
// None.
//
// Return Value:
//
// None.
//
//--
LEAF_ENTRY(FlushWriteBuffer)
.set noreorder
.set noat
nop // four nop's are required
nop //
nop //
nop //
10: //
bc0f 10b // if false, write buffer not empty
nop //
j ra // return
nop
.end FlushWritebuffer
RomRemoteSpeedValues:
//
// This table contains the default values for the remote speed regs.
//
.byte REMSPEED1 // ethernet
.byte REMSPEED2 // SCSI
.byte REMSPEED3 // Floppy
.byte REMSPEED4 // RTC
.byte REMSPEED5 // Kbd/Mouse
.byte REMSPEED6 // Serial port
.byte 7 // New dev
.byte REMSPEED8 // Parallel
.byte REMSPEED9 // NVRAM
.byte REMSPEED10 // Int src reg
.byte REMSPEED11 // PROM
.byte REMSPEED12 // Sound
.byte 7 // New dev
.byte REMSPEED14 // External Eisa latch
.align 4
MctadrTest:
//
// Test the mctadr registers.
//
bal PutLedDisplay
ori a0,zero,LED_MCTADR_RESET
//
// check chip reset values
//
MctadrReset:
li t0,DEVICE_VIRTUAL_BASE // Get base address of MCTADR
lw v0,DmaConfiguration(t0) // Check Config reset value
li t1,CONFIG_RESET //
bne v0,t1,MctadrResetError
lw v0,DmaInvalidAddress(t0)
lw v1,DmaTranslationBase(t0)
bne v0,zero,MctadrResetError// Check LFAR reset value
lw v0,DmaTranslationLimit(t0)
bne v1,zero,MctadrResetError// Check Ttable base reset value
lw v1,DmaRemoteFailedAddress(t0)
bne v0,zero,MctadrResetError// Check TT limit reset value
lw v0,DmaMemoryFailedAddress(t0)
bne v1,zero,MctadrResetError// Check RFAR reset value
lw v1,DmaByteMask(t0)
bne v0,zero,MctadrResetError// Check MFAR reset value
addiu t1,t0,DmaRemoteSpeed0 // address of REM_SPEED 0
bne v1,zero,MctadrResetError// Check TT_BMASK reset value
addiu t2,t0,DmaRemoteSpeed15 // address of REM_SPEED 15
lw v0,0(t1) // read register
li t3,REMSPEED_RESET //
addiu t1,t1,8 // next register address.
NextRemSpeed:
bne v0,t3,MctadrResetError // Check Rem speed reg reset value
lw v0,0(t1) // read next rem speed
bne t1,t2,NextRemSpeed
addiu t1,t1,8 // next register address.
bne v0,t3,MctadrResetError // Check last Rem speed reg reset value
addiu t1,t0,DmaChannel0Mode // address of CHAN0MODE register
addiu t2,t0,DmaChannel7Address// address of DMA_CHAN7ADDR (last reg)
lw v0,0(t1) // read register
addiu t1,t1,8 // next register address.
NextChannelReg:
bne v0,zero,MctadrResetError// Check channel reg reset value
lw v0,0(t1) // read next channel
bne t1,t2,NextChannelReg
addiu t1,t1,8 // next register address.
bne v0,zero,MctadrResetError// Checklast channel reg reset value
lw v0,DmaInterruptSource(t0) // read DMA Channel interrupt
lw v1,DmaErrortype(t0) // read eisa/ethernet error reg
bne v0,zero,MctadrResetError// check Intpend
lw v0,DmaRefreshRate(t0)
bne v1,zero,MctadrResetError// check Eisa error type reset value
li t1,REFRRATE_RESET
bne v0,t1,MctadrResetError // check Refresh rate reset value
lw v0,DmaSystemSecurity(t0)
li t1,SECURITY_RESET
bne v0,t1,MctadrResetError // check Security reg reset value
lw v0,DmaInterruptAcknowledge(t0) // read register but don't check
//
// now perform a register test
//
bal PutLedDisplay
ori a0,zero,LED_MCTADR_REG // Next test Led value
MctadrReg:
//
// Check the data path between R4K and Mctadr by writing to Byte mask reg.
//
li t0,DEVICE_VIRTUAL_BASE
sw zero,DmaCacheMaintenance(t0) // select cache block zero.
li t1,1
sw t1,DmaLogicalTag(t0) // Set LFN=zero, Offset=0 , Direction=READ from memory, Valid
li t2,0x55555555
bal FlushWriteBuffer
sw t2,DmaByteMask(t0) // write patten to Byte mask
lw v0,DmaByteMask(t0) // read Byte mask
sw t1,DmaPhysicalTag(t0) // PFN=0 and Valid
bne v0,t2,MctadrRegError //
addu t2,t2,t2 // t1=0xAAAAAAAA
bal FlushWriteBuffer
sw t2,DmaByteMask(t0) // write patten to Byte mask
lw v0,DmaByteMask(t0) // read Byte mask
li t2,0xFFFFFFFF // expected value
bne v0,t2,MctadrRegError // Check byte mask
li a0,0xA0000000 // get memory address zero.
bal FlushWriteBuffer
sw zero,0(a0) // write address zero -> flushes buffers
lw v0,DmaByteMask(t0) // read Byte mask
//
//Initialize mem config to 64MB and Write to some registers
//
li t1,0x17F
sw t1,DmaConfiguration(t0) // Init Global Config
li t2,0x1555000 //
sw t2,DmaTranslationBase(t0)// write to TT BASE
li t4,MEMORY_REFRESH_RATE
sw t4,DmaRefreshRate(t0) // Initialize REFRESH RATE
li t3,0x5550
bal FlushWriteBuffer
sw t3,DmaTranslationLimit(t0) // write to TT_limit
lw v0,DmaConfiguration(t0) // READ GLOBAL CONFIG
lw v1,DmaTranslationBase(t0) // read TT BASE
bne v0,t1,MctadrRegError // check GLOBAL CONFIG
lw v0,DmaTranslationLimit(t0) // read TT_limit
bne v1,t2,MctadrRegError // check TT-BASE
lw v1,DmaRefreshRate(t0) // Read REFRESH RATE
bne v0,t3,MctadrRegError // check TT-LIMIT
li t1,0x2AAA000
bne v1,t4,MctadrRegError // check REFRESH RATE
li t2,0xAAA0
sw t1,DmaTranslationBase(t0) // write to TT BASE
bal FlushWriteBuffer
sw t2,DmaTranslationLimit(t0) // write to TT_limit
lw v0,DmaTranslationBase(t0) // read TT BASE
lw v1,DmaTranslationLimit(t0) // read TT_limit
bne v0,t1,MctadrRegError // check TT-BASE
li t1,TT_BASE_ADDRESS // Init translation table base address
sw t1,DmaTranslationBase(t0) // Init TT BASE
bne v1,t2,MctadrRegError // check TT-LIMIT
sw zero,DmaTranslationLimit(t0) // clear TT-limit
//
// Initialize remote speed registers.
//
addiu t1,t0,DmaRemoteSpeed1 // address of REM_SPEED 1
la a1,RomRemoteSpeedValues - LINK_ADDRESS + RESET_VECTOR //
addiu t2,a1,14 // addres of last value
WriteNextRemSpeed:
lbu v0,0(a1) // load init value for rem speed
addiu a1,a1,1 // compute next address
sw v0,0(t1) // write to rem speed reg
bne a1,t2,WriteNextRemSpeed // check for end condition
addiu t1,t1,8 // next register address
bal FlushWriteBuffer
addiu a1,t2,-14 // address of first value for rem speed register
addiu t1,t0,DmaRemoteSpeed1 // address of REM_SPEED 1
lbu v1,0(a1) // read expected value
CheckNextRemSpeed:
lw v0,0(t1) // read register
addiu a1,a1,1 // address of next value
bne v0,v1,MctadrRegError // check register
addiu t1,t1,8 // address of next register
bne a1,t2,CheckNextRemSpeed // check for end condition
lbu v1,0(a1) // read expected value
//
// Now test the DMA channel registers
//
addiu t1,t0,DmaChannel0Mode // address of channel 0
addiu t2,t1,8*DMA_CHANNEL_GAP // last address of channel regs
li a0,0x15 // Mode
li a1,0x2 // enable
li a2,0xAAAAA // byte count
li a3,0x555555 // address
WriteNextChannel:
sw a0,0(t1) // write mode
sw a1,0x8(t1) // write enable
sw a2,0x10(t1) // write byte count
sw a3,0x18(t1) // write address
addiu t1,t1,DMA_CHANNEL_GAP // compute address of next channel
addiu a2,a2,1 // change addres
bne t1,t2,WriteNextChannel
addiu a3,a3,-1 // change Byte count
bal FlushWriteBuffer // flush
//
// Check channel regs.
//
addiu t1,t0,DmaChannel0Mode // address of channel 0
addiu t2,t1,8*DMA_CHANNEL_GAP // last address of channel regs
li a2,0xAAAAA // byte count
li a3,0x555555 // address
CheckNextChannel:
lw t4,0x0(t1) // read mode
lw t5,0x8(t1) // read enable
bne t4,a0,MctadrRegError // check mode
lw t4,0x10(t1) // read byte count
bne t5,a1,MctadrRegError // check enable
lw t5,0x18(t1) // read address
bne t4,a2,MctadrRegError // check abyte count
addiu a2,a2,1 // next expected byte count
bne t5,a3,MctadrRegError // check address
addiu t1,t1,DMA_CHANNEL_GAP // next channel address
bne t1,t2,CheckNextChannel
addiu a3,a3,-1
//
// Now do a second test on DMA channel registers
//
addiu t1,t0,DmaChannel0Mode // address of channel 0
addiu t2,t1,8*DMA_CHANNEL_GAP // last address of channel regs
li a0,0x2A // Mode
li a2,0x55555 // byte count
li a3,0xAAAAAA // address
WriteNextChannel2:
sw a0,0(t1) // write mode
sw a2,0x10(t1) // write byte count
sw a3,0x18(t1) // write address
addiu t1,t1,DMA_CHANNEL_GAP // compute address of next channel
addiu a2,a2,1 // change addres
bne t1,t2,WriteNextChannel2
addiu a3,a3,-1 // change Byte count
bal FlushWriteBuffer // flush
//
// Check channel regs.
//
addiu t1,t0,DmaChannel0Mode // address of channel 0
addiu t2,t1,8*DMA_CHANNEL_GAP // last address of channel regs
li a2,0x55555 // byte count
li a3,0xAAAAAA // address
CheckNextChannel2:
lw t4,0x0(t1) // read mode
lw t5,0x10(t1) // read byte count
bne t4,a0,MctadrRegError // check mode
lw t4,0x18(t1) // read address
bne t5,a2,MctadrRegError // check abyte count
addiu a2,a2,1 // next expected byte count
bne t4,a3,MctadrRegError // check address
addiu t1,t1,DMA_CHANNEL_GAP // next channel address
bne t1,t2,CheckNextChannel2
addiu a3,a3,-1
//
// Now zero the channel registers
//
addiu t1,t0,DmaChannel0Mode // address of channel 0
addiu t2,t1,8*DMA_CHANNEL_GAP // last address of channel regs
ZeroChannelRegs:
addiu t1,t1,8
bne t1,t2,ZeroChannelRegs
sw zero,-8(t1) // clear reg
bal FlushWriteBuffer // flush
addiu t1,t0,DmaChannel0Mode // address of channel 0
addiu t2,t1,8*DMA_CHANNEL_GAP // last address of channel regs
CheckZeroedChannelRegs:
lw a0,0(t1)
addiu t1,t1,8 // next channel
bne a0,zero,MctadrRegError // check
nop
bne t1,t2,CheckZeroedChannelRegs
nop
//
// Address chip test passed if code reaches this point
// Skip over error case routines.
//
b MapROM // go for the ROM Checksum
//
// Address chip error routines.
//
MctadrRegError:
li t0,DIAGNOSTIC_VIRTUAL_BASE // get base address of diag register
lb t0,0(t0) // read register value.
li t1,LOOP_ON_ERROR_MASK // get value to compare
andi t0,DIAGNOSTIC_MASK // mask diagnostic bits.
li v0,PROM_ENTRY(14) // load address of PutLedDisplay
beq t1,t0,10f // branch if loop on error.
ori a0,zero,LED_MCTADR_REG // load LED display value.
lui t0,LED_BLINK // get LED blink code
jal v0 // Blink LED and hang.
or a0,a0,t0 // pass argument in a0
10:
lui t0,LED_LOOP_ERROR // get LED LOOP_ERROR code
jal v0 // Set LOOP ON ERROR on LED
or a0,a0,t0 // pass argument in a0
b MctadrReg
nop
MctadrResetError:
li t0,DIAGNOSTIC_VIRTUAL_BASE // get base address of diag register
lb t0,0(t0) // read register value.
li t1,LOOP_ON_ERROR_MASK // get value to compare
andi t0,DIAGNOSTIC_MASK // mask diagnostic bits.
li v0,PROM_ENTRY(14) // load address of PutLedDisplay
beq t1,t0,10f // branch if loop on error.
ori a0,zero,LED_MCTADR_RESET // load LED display value.
lui t0,LED_BLINK // get LED blink code
jal v0 // Blink LED and hang.
or a0,a0,t0 // pass argument in a0
10:
lui t0,LED_LOOP_ERROR // get LED LOOP_ERROR code
jal v0 // Set LOOP ON ERROR on LED
or a0,a0,t0 // pass argument in a0
b MctadrReset
nop
//
// Map the rom into the TLB so can run from virtual address space.
//
MapROM:
bal PutLedDisplay
ori a0,zero,LED_ROM_CHECKSUM
//
// initialize the TLB to map the whole ROM. This takes 16 or 32 entries.
//
li t0,ROM_LO // entry lo
li t1,ROM_HI // entry hi
li t2,(1<<INDEX_INDEX) // first index
li t3,ROM_TLB_ENTRIES*(1<<INDEX_INDEX) // last index
RomTlbLoop:
mtc0 t2,index
mtc0 t0,entrylo
mtc0 t1,entryhi
addiu t0,PAGE_SIZE // compute next entry lo
addiu t1,PAGE_SIZE // compute next entry hi
tlbwi // write tlb entry
bne t2,t3,RomTlbLoop // check for end of loop
addiu t2,(1<<INDEX_INDEX) // compute next index
//
// now go to the virtual address instead of using the page
// 1FC00000 that is mapped by the address chip.
//
la t0,Virtual
j t0
nop
Virtual:
//
// Perform a ROM Checksum.
//
li a0,PROM_VIRTUAL_BASE // address of PROM
li t0,ROM_SIZE-8
add a1,a0,t0 // end of loop address
move t0,zero // init sum register
RomCheckSum:
lw t1,0(a0) // fetch word
lw t2,4(a0) // fetch second word
addu t0,t0,t1 // calculate checksum
addiu a0,a0,8 // compute next address
bne a0,a1,RomCheckSum // check end of loop condition
addu t0,t0,t2 // calculate checksum
lw t1,0(a0) // fetch last word
lw t2,4(a0) // fetch expected checksum value
addu t0,t0,t1 // calculate checksum
//
// if test passes, jump to next part of initialization code.
//
beq t2,t0,TestMemory // Go if calculated checksum is correct
lui a0,LED_BLINK // otherwise hang
bal PutLedDisplay // by calling PutLedDisplay
ori a0,a0,LED_ROM_CHECKSUM // blinking the test number
//
// Test the first portion of the memory. Code is fetched from the PROM
//
TestMemory:
bal PutLedDisplay // call PutLedDisplay to show that
ori a0,zero,LED_MEMORY_TEST_1 // Mem test is starting
//
// Call memory test routine to test small portion of memory.
// a0 is start of tested memory. a1 is length in bytes to test
//
li a0,KSEG1_BASE // start of mem test test
ori a1,zero,MEMTEST_SIZE // length to test in bytes
bal WriteNoXorAddressTest
move a2,zero // xor pattern zero
lui a3,LED_BLINK
bal CheckNoXorAddressTest
ori a3,LED_MEMORY_TEST_1 // set LED blink in case of Error
nop
//
// Do the same flipping all bits
//
bal WriteAddressTest
li a2,-1 // Xor pattern = FFFFFFFF
bal CheckAddressTest
nop
//
// Do the same flipping some bits to be sure parity bits are flipped in each byte
//
lui a2,0x0101
bal WriteAddressTest
ori a2,a2,0x0101 // Xor pattern = 01010101
bal CheckAddressTest
nop
//
// Now test the tlb by writing to the tested memory
//
//
// Perform a tlb test. Entries 0-16 are used to map the LED and the ROM the
// rest are invalid.
//
bal PutLedDisplay // call PutLedDisplay to show that
ori a0,zero,LED_TLB_TEST // TLB test is starting
li t0,(ROM_TLB_ENTRIES+1)*(1<<INDEX_INDEX) // index of first available entry
li t1,TLB_TEST_HI // address in user space
li t2,TLB_TEST_LO
li t3,KSEG1_BASE | TLB_TEST_PHYS// Kseg1 address of the
// same place as the mapped addresses
sw t1,0(t3) // store word
li t5,64*(1<<INDEX_INDEX) // last index
mtc0 t2,entrylo
NextEntry:
mtc0 t0,index
mtc0 t1,entryhi
nop
tlbwi
TlbTestBegin: // Start of block where tlb misses
nop // are not allowed.
lw t4,0(t1) // load address from address
addiu t0,(1<<INDEX_INDEX) // compute next index
bne t4,t1, TlbError //
addiu t4,t1,PAGE_SIZE // compute next virtual address
sw t4,0(t1) // write next address in address
bne t0,t5,NextEntry // check for tlb full
move t1,t4 // copy virtual address to map
TlbTestEnd: // End of block where tlb misses are forbiden
//
// TLB test passed. If there had been an error, there would have been
// a trap, and the trap would have jumped to the following TlbError routine.
// Test passed if code got to here. Go initialize caches.
//
b InitCaches
nop
//
// TLB test failure routine.
//
TlbError:
lui a0,LED_BLINK // if error hang
bal PutLedDisplay // while displaying
ori a0,LED_TLB_TEST // the test number
// .globl TlbReInit
//TlbReInit:
// la t0,TlbInit - LINK_ADDRESS + RESET_VECTOR
// j t0
// nop
.globl TlbInit
TlbInit:
/*++
Routine Description:
This routine will initialize the TLB for virtual addressing. There
will be 6 basic mappings initially until the operating system sets up a
full virtual address mapping. Mapped items will include and the virtual
mapping will be:
main memory A0000000 - A0800000 (uncached)
main memory 80000000 - 80800000 (cached)
note that these will not be actual entries because they
automatically get mapped as kseg[1:0]
I/O device E0000000 - E00FFFFF
Intr src reg E0100000 - E0100FFF
video cntr E0200000 - E0203FFF
video memory E0800000 - E0FFFFFF
prom space E1000000 - E100FFFF
eisa i/o space E2000000 - E2FFFFFF
eisa mem space E3000000 - E3FFFFFF
reserved E4000000 -
All other unused TLB entries will be marked invalid using addresses
from the reserved region.
The general algorithm for loading a cache entry is as follows:
Load Hi register with virtual address and protection bits.
Load Lo[1:0] register with Physical address and protection bits.
Load mask register with range of bits to compare with TLB tag.
Load Index register to point to TLB entry.
Store with a PLBWI instruction.
Note:
This routine must be loaded in the first page of the rom.
Arguments:
None.
Return Value:
None.
Revision History:
Added R3000 stuff. Use 16 entries to map 64K of rom and another
16 entries to map I/O space. Next five entries will be used for
video controllers, and tlb miss handler will use only entry #37.
--*/
//
// Prom space
//
li t0,ROM_LO //entrylo
li t2,ROM_HI //entryhi
li t4,(ROM_TLB_ENTRIES << INDEX_INDEX) // loop count
move t5,zero // first index
rom_tlb:
mtc0 t0,entrylo // store entry lo
mtc0 t2,entryhi // store entry high
mtc0 t5,index // store index
addiu t0,t0,(1 << ENTRYLO_PFN) // increment for next page
tlbwi // store tlb entry
addiu t5,t5,(1<<INDEX_INDEX) // next index
bne t4,t5,rom_tlb // exit loop when whole rom mapped
addiu t2,t2,(1 << ENTRYHI_VPN) // increment for next page
//
// I/O Device space
//
li t0,DEVICE_LO //entrylo
li t2,DEVICE_HI //entryhi
li t4,((DEVICE_TLB_ENTRIES+ROM_TLB_ENTRIES)<<INDEX_INDEX) // last index
device_tlb:
mtc0 t0,entrylo // store entry lo
mtc0 t2,entryhi // store entry high
mtc0 t5,index // store index
addiu t0,t0,(1 << ENTRYLO_PFN) // increment for next page
tlbwi // store tlb entry
addiu t5,t5,(1<<INDEX_INDEX) // next index
bne t4,t5,device_tlb // exit loop when whole rom mapped
addiu t2,t2,(1 << ENTRYHI_VPN) // increment for next page
//
// Interrupt source register space
//
li t0,PROC_LO //entrylo
li t2,PROC_HI //entryhi
mtc0 t0,entrylo // store entry lo
mtc0 t2,entryhi // store entry high
mtc0 t5,index // store index
addiu t5,t5,(1<<INDEX_INDEX) // compute next index
tlbwi // store tlb entry
//
// video register space
//
li t0,VID_LO //entrylo
li t2,VID_HI //entryhi
mtc0 t0,entrylo // store entry lo
mtc0 t2,entryhi // store entry high
mtc0 t5,index // store index
addiu t5,t5,(1<<INDEX_INDEX) // next index
tlbwi // store tlb entry
//
// cursor register space
//
li t0,CURSOR_LO //entrylo
li t2,CURSOR_HI //entryhi
mtc0 t0,entrylo // store entry lo
mtc0 t2,entryhi // store entry high
mtc0 t5,index // store index
addiu t5,t5,(1<<INDEX_INDEX) // next free
tlbwi // store tlb entry
//
// Map the two first pages of video memory to avoid taking traps when
// displaying on the first line of the screen
//
li t0,VIDMEM_LO //entrylo
li t2,VIDMEM_HI //entryhi
mtc0 t0,entrylo // store entry lo
mtc0 t2,entryhi // store entry high
mtc0 t5,index // store index
addiu t0,t0,(1 << ENTRYLO_PFN) // second page phys
tlbwi // store tlb entry
addiu t2,t2,(1 << ENTRYHI_VPN) // second page virt
addiu t5,t5,(1<<INDEX_INDEX)
mtc0 t0,entrylo
mtc0 t2,entryhi
mtc0 t5,index
addiu t5,t5,(1<<INDEX_INDEX)
tlbwi // store tlb entry
//
// zero the rest of the unused entries.
#define RESV ((1 << ENTRYLO_G) + \
(1 << ENTRYLO_N))
li t0,RESV //entrylo
li t2,((RESV_VIRT >> 12) << ENTRYHI_VPN) //entryhi
li t4,(64 << INDEX_INDEX) // last entry
zero_tlb:
mtc0 t0,entrylo // store entry lo
mtc0 t2,entryhi // store entry high
mtc0 t5,index // store index
addiu t0,t0,(1 << ENTRYLO_PFN) // increment for next page
tlbwi // store tlb entry
addiu t5,t5,(1<<INDEX_INDEX)
bne t5,t4,zero_tlb
addiu t2,t2,(1 << ENTRYHI_VPN) // increment for next page
j ra
nop
InitCaches:
//
// Copy routines to the tested memory at the same offset
// from the beginning of memory that they are from the beginning of ROM
// These are, Memory Tests, Zero Memory, PutLedDisplay and DataCopy
//
// calculate arguments for DataCopy call
// a0 is source of data, a1 is dest, a2 is length in bytes
//
la a0,MemoryRoutines // source
la a1,MemoryRoutines-LINK_ADDRESS+KSEG1_BASE // destination location
la t2,EndMemoryRoutines // end
bal DataCopy
sub a2,t2,a0 // length of code
//
// Call Cache initialization routine, run it from memory
// different routines for R4000 and R3000
//
bal PutLedDisplay
ori a0,zero,LED_CACHE_INIT
la s1,R3000CacheInit-LINK_ADDRESS+KSEG1_BASE
jal s1 // flush data cache
li s0, ((1 << PSR_SWC) | (1 << PSR_BEV)) // set bit to swap ic
mtc0 s0,psr // and bev
nop
jal s1 // flush icache
nop
//
// call routine now in non cached memory to test bigger portion of memory
//
bal PutLedDisplay // display that memory test
ori a0,zero,LED_WRITE_MEMORY_2 // is starting
li a0,KSEG1_BASE+MEMTEST_SIZE // start of memory to write non cached
li a1,ROM_SIZE+STACK_SIZE // test the memory needed to copy the code
// to memory and for the stack
la s1,WriteNoXorAddressTest-LINK_ADDRESS+KSEG1_BASE // address of routine in memory
jal s1 // Write and therefore init mem.
move a2,zero // xor pattern
la s2,CheckNoXorAddressTest-LINK_ADDRESS+KSEG1_BASE // address of routine in memory
jal s2 // Check written memory
ori a3,zero,LED_READ_MEMORY_2 // load LED value if memory test fails
la s1,WriteAddressTest-LINK_ADDRESS+KSEG1_BASE // address of routine in memory
li a0,KSEG0_BASE+MEMTEST_SIZE // start of memory now cached
li a2,0xDFFFFFFF // to flipp all bits
jal s1 // Write second time now cached.
la s2,CheckAddressTest-LINK_ADDRESS+KSEG1_BASE // address of routine in memory
jal s2 // check also cached.
nop
lui a2,0x0101
jal s1 // Write third time cached.
ori a2,a2,0x0101 // flipping some bits
jal s2 // check also cached.
nop
//
// if we come back, the piece of memory is tested and therefore initialized.
// The Dcache is also tested.
// Perform the Icache test now.
//
bal PutLedDisplay // display that the icache test
ori a0,zero,LED_ICACHE // is starting
la t0,nop_opcode // get address of nop instruction
lw a0,0(t0) // fetch nop opcode
la t1,R3000ICacheTest-LINK_ADDRESS+KSEG1_BASE // Address of routine in memory
jal t1
lw a1,4(t0) // fetch j ra opcode.
//
// Flush the Icache so that when we run the copy routine cached we
// don't execute the nops again.
//
li s0, ((1 << PSR_SWC) | (1 << PSR_BEV)) // set bit to swap ic
mtc0 s0,psr // and bev
la s1,R3000CacheInit-LINK_ADDRESS+KSEG1_BASE
jal s1 // flush data cache
nop
//
// Now Put the entry point of the TLBMiss exception to be able to
// access the video Memory
//
bal PutLedDisplay // display that the VideoMemory
ori a0,zero,LED_VIDEOMEM // is being tested.
li t0,EXCEPTION_JUMP_TABLE // base address of table
la t1,TLBMiss // address of TLB Miss handler
sw t1,8(t0) // use it in User TLB Miss
sw t1,12(t0) // and the other TLB exception
la t0,TlbInit - LINK_ADDRESS + RESET_VECTOR
jal t0 // Init the TLB runing at the ResetVector Page
nop
bal SizeMemory // Go to size the memory
nop // If we return, the global config
// is set to the proper configuration.
//
// SELFCOPY
// load addresses to copy and jump to copy in memory routine.
//
bal PutLedDisplay // Display That SelfCopy Starts
ori a0,zero,LED_SELFCOPY //
la s0,DataCopy-LINK_ADDRESS+KSEG0_BASE// address of copy routine in cached space
la a0,end // end of this file = begining of
// next.
li a1,RAM_TEST_DESTINATION_ADDRESS // destination is linked address.
andi t0,a0,0xFFFF // get offset of code address
li a2,ROM_SIZE // load size of prom
subu a2,a2,t0 // size to copy is rest of prom.
jal s0 // jump to copy
nop
li t0,RAM_TEST_LINK_ADDRESS // load address of code.
//
// Initialize the stack to the first page of memory and Call Rom tests
// if the stack grows to much it will overwrite the MemoryTest routine
// and PutLedDisplay...
//
li sp,RAM_TEST_STACK_ADDRESS-16 // init stack
jal t0 // jump to code in memory
nop
99:
b 99b // hang if we get here.
nop //
/*++
SizeMemory(
);
Routine Description:
This routine sizes the memory and writes the proper value into
the GLOBAL CONFIG register.
The way memory is sized is the following:
The global config is ALREADY set to 64MB
for each bank base address i.e 48,32,16,0 MB
ID0 is written to offset 0 from base of bank
ID4 is written to offseet 4MB from base of bank
Data is read from offset 0 then:
if ID4 is found the SIMMs at the current bank are 1MB SIMMs
and 4MB wrapped to 0MB.
if ID0 is found at offset 0 and ID4 is found at offset 4MB,
then SIMMs at bank are 4Mb SIMMs.
if data does not match or a parity exception is taken
then memory is not present in that bank.
Arguments:
None.
Return Value:
If the installed memory is inconsistent, does not return
and the LED flashes A.E
--*/
#define MEM_ID0 0x0A0A0A0A
#define MEM_ID4 0xF5F5F5F5
LEAF_ENTRY(SizeMemory)
.set noat
.set noreorder
li t0,EXCEPTION_JUMP_TABLE // get base address of table
la t1,DBEHandler // get DBE handler address
sw t1,XCODE_DATA_BUS_ERROR(t0) // Install handler in table
li t0,0xA3000000 // get address 48MB
li t1,MEM_ID0 // get ID0
li t2,0xA3400000 // get address 52MB
li t3,MEM_ID4 // get ID4
li s0,3 // counts how many banks left to check
move t8,zero // t8 stores the present banks
move t9,zero // t9 stores the size of the banks
SizeBank:
move a1,zero // set current bank to 1 MB by default
sw t1,0x0(t0) // fill whole memory line at base of bank
sw t1,0x4(t0)
sw t1,0x8(t0)
sw t1,0xC(t0)
sw t3,0x0(t2) // fill whole memory line at base of bank + 4MB
sw t3,0x4(t2)
sw t3,0x8(t2)
sw t3,0xC(t2)
//
// Check written data
//
move v1,zero // init v1 to zero
.align 4 // align address so that Parity Handler
// can easily determine if it happened here
ExpectedDBE:
lw t4,0x0(t0) // read whole memory line.
lw t5,0x4(t0) // the four words must be identical
lw t6,0x8(t0) //
lw t7,0xC(t0) //
DBEReturnAddress:
bne v1,zero,10f // if v1!=0 Parity exception occurred.
move a0,zero // tells that bank not present
bne t4,t5,10f // check for consistency
nop
bne t4,t6,10f // check for consistency
nop //
bne t4,t7,10f // check for consistency
nop //
beq t4,t3,10f // If ID4 is found at PA 0
li a0,0x1 // bank is present and SIMMS are 1 MB
bne t4,t1,10f // if neither ID4 nor ID0 is found
move a0,zero // no memory in bank
li a0,0x1 // bank is present and SIMMS
// look like they are 4 MB
//
// ID written at Address 0 has been correctly checked
// Now check the ID written at address 4MB
//
lw t4,0x0(t2) // read whole memory line.
lw t5,0x4(t2) // the four words must be identical
bne t3,t4,10f // check for consistency
lw t6,0x8(t2) //
bne t3,t5,10f // check for consistency
lw t7,0xC(t2) //
bne t3,t6,10f // check for consistency
nop //
bne t3,t7,10f // check for consistency
nop
li a1,0x1 // If all matches SIMMs are 4MB
10: //
// a0 has the value 0 if no memory in bank 1 if memory in bank
// a1 has the value 0 if 1MB SIMMS 1 if 4MB SIMMS
//
or t8,t8,a0 // accummulate present banks
or t9,t9,a1 // accummulate size of banks
//
// Check if last bank
//
beq s0,zero,Done
//
// Now set addresses to check next bank
//
li AT,0x01000000 // load 16MB
subu t0,t0,AT // substract to base address
subu t2,t2,AT // substract to base address + 4MB
sll t8,t8,1 // make room for next bank
sll t9,t9,1 // make room for next bank
b SizeBank // go to size next memory bank
addiu s0,s0,-1 // substract one to the num of banks left
Done: //
// t8 has the present banks in bits 3-0 for banks 3-0
// t9 has the size of the banks in bits 3-2 and 1-0
//
// Check that memory is present in bank zero
//
andi t0,t8,1
beq t0,zero,WrongMemory
sll t8,t8,2 // shift bank enable bits to bits 5-2
andi t9,t9,0x3 // get rid of bits 2-3
or t8,t9,t8 // or size of banks with present banks
ori v0,t8,0x340 // Set Video RAM size map PROM bit and init timer.
li t0,DEVICE_VIRTUAL_BASE // Get base address of MCTADR
sw v0,DmaConfiguration(t0) // Store computed Config
j ra // return to caller.
nop
WrongMemory:
//
// Control reaches here if the memory can't be sized.
//
lui a0,LED_BLINK // Hang
bal PutLedDisplay // blinking the error code
ori a0,a0,LED_WRONG_MEMORY // in the LED
.end SizeMemory
/*++
DBEHandler();
Routine Description:
This routine is called as a result of a DBE
It checks if the exception occurred while sizing the memory
if this is the case, it sets v0=1 and returns to the right
place.
If the exception occurred somewhere else, returns to WrongMemory
where the error code is displayed in the LED.
Arguments:
This routine does not preserve the contents of v1
Return Value:
Returns to the right place to avoid taking the exception again
--*/
LEAF_ENTRY(DBEHandler)
li k0,DEVICE_VIRTUAL_BASE // get base address of MCTADR
lw k1,DmaInterruptSource(k0) // read Interrupt pending register
li k0,(1<<8) // mask to test bit 8
and k1,k0,k1 // test for parity error
beq k1,k0,ParityError // branch if parity error
li k0,DEVICE_VIRTUAL_BASE // get base address of MCTADR
lw k1,DmaInvalidAddress(k0) // read lfar to clear error
b NotExpectedReturn // return
nop
ParityError:
lw k1,DmaMemoryFailedAddress(k0) // read MFAR to clear bit 8
lw k1,DmaParityDiagnosticLow(k0) // clear error in parity diag reg.
mfc0 k0,epc // get address of exception
li k1,0xFFFFFFF0 // mask to align address of exception
and k0,k1,k0 // align epc
la k1,ExpectedDBE // get address where exception is expected
beq k0,k1,ExpectedReturn// if equal return
nop
NotExpectedReturn:
la k0,WrongMemory // set return address
j ra // return to dispatcher
nop // which will restore ra and return to K0
ExpectedReturn:
la k0,DBEReturnAddress // set return address
j ra // return to dispatcher which will restore ra and return to K0
addiu v1,zero,1 // set v1 to 1 to signal exception occurred
.end DBEHandler
#endif //JAZZ && R3000
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