ref: 83246e296ea433b65b9d295b5e08fedd39ff1ab7
dir: /os/boot/bitsy/l.s/
#include "mem.h"
/*
* Entered here from Compaq's bootldr with MMU disabled.
*/
TEXT _start(SB), $-4
MOVW $setR12(SB), R12 /* load the SB */
_main:
/* SVC mode, interrupts disabled */
MOVW $(PsrDirq|PsrDfiq|PsrMsvc), R1
MOVW R1, CPSR
/* disable the MMU */
MOVW $0x130, R1
MCR CpMMU, 0, R1, C(CpControl), C(0x0)
/* flush caches */
MCR CpMMU, 0, R0, C(CpCacheFlush), C(0x7), 0
/* drain prefetch */
MOVW R0,R0
MOVW R0,R0
MOVW R0,R0
MOVW R0,R0
/* drain write buffer */
MCR CpMMU, 0, R0, C(CpCacheFlush), C(0xa), 4
MOVW $(MACHADDR+BY2PG), R13 /* stack */
SUB $4, R13 /* link */
BL main(SB)
BL exit(SB)
/* we shouldn't get here */
_mainloop:
B _mainloop
BL _div(SB) /* hack to get _div etc loaded */
/* flush tlb's */
TEXT mmuinvalidate(SB), $-4
MCR CpMMU, 0, R0, C(CpTLBFlush), C(0x7)
RET
/* flush tlb's */
TEXT mmuinvalidateaddr(SB), $-4
MCR CpMMU, 0, R0, C(CpTLBFlush), C(0x6), 1
RET
/* write back and invalidate i and d caches */
TEXT cacheflush(SB), $-4
/* write back any dirty data */
MOVW $0xe0000000,R0
ADD $(8*1024),R0,R1
_cfloop:
MOVW.P 32(R0),R2
CMP.S R0,R1
BNE _cfloop
/* drain write buffer and invalidate i&d cache contents */
MCR CpMMU, 0, R0, C(CpCacheFlush), C(0xa), 4
MCR CpMMU, 0, R0, C(CpCacheFlush), C(0x7), 0
/* drain prefetch */
MOVW R0,R0
MOVW R0,R0
MOVW R0,R0
MOVW R0,R0
RET
/* write back d cache */
TEXT cachewb(SB), $-4
/* write back any dirty data */
_cachewb:
MOVW $0xe0000000,R0
ADD $(8*1024),R0,R1
_cwbloop:
MOVW.P 32(R0),R2
CMP.S R0,R1
BNE _cwbloop
/* drain write buffer */
MCR CpMMU, 0, R0, C(CpCacheFlush), C(0xa), 4
RET
/* write back a single cache line */
TEXT cachewbaddr(SB), $-4
BIC $31,R0
MCR CpMMU, 0, R0, C(CpCacheFlush), C(0xa), 1
B _wbflush
/* write back a region of cache lines */
TEXT cachewbregion(SB), $-4
MOVW 4(FP),R1
CMP.S $(4*1024),R1
BGT _cachewb
ADD R0,R1
BIC $31,R0
_cwbrloop:
MCR CpMMU, 0, R0, C(CpCacheFlush), C(0xa), 1
ADD $32,R0
CMP.S R0,R1
BGT _cwbrloop
B _wbflush
/* invalidate the dcache */
TEXT dcacheinvalidate(SB), $-4
MCR CpMMU, 0, R0, C(CpCacheFlush), C(0x6)
RET
/* invalidate the icache */
TEXT icacheinvalidate(SB), $-4
MCR CpMMU, 0, R0, C(CpCacheFlush), C(0x9)
RET
/* drain write buffer */
TEXT wbflush(SB), $-4
_wbflush:
MCR CpMMU, 0, R0, C(CpCacheFlush), C(0xa), 4
RET
/* return cpu id */
TEXT getcpuid(SB), $-4
MRC CpMMU, 0, R0, C(CpCPUID), C(0x0)
RET
/* return fault status */
TEXT getfsr(SB), $-4
MRC CpMMU, 0, R0, C(CpFSR), C(0x0)
RET
/* return fault address */
TEXT getfar(SB), $-4
MRC CpMMU, 0, R0, C(CpFAR), C(0x0)
RET
/* return fault address */
TEXT putfar(SB), $-4
MRC CpMMU, 0, R0, C(CpFAR), C(0x0)
RET
/* set the translation table base */
TEXT putttb(SB), $-4
MCR CpMMU, 0, R0, C(CpTTB), C(0x0)
RET
/*
* enable mmu, i and d caches
*/
TEXT mmuenable(SB), $-4
MRC CpMMU, 0, R0, C(CpControl), C(0x0)
ORR $(CpCmmuena|CpCdcache|CpCicache|CpCwb), R0
MCR CpMMU, 0, R0, C(CpControl), C(0x0)
RET
TEXT mmudisable(SB), $-4
MRC CpMMU, 0, R0, C(CpControl), C(0x0)
BIC $(CpCmmuena|CpCdcache|CpCicache|CpCwb|CpCvivec), R0
MCR CpMMU, 0, R0, C(CpControl), C(0x0)
RET
/*
* use exception vectors at 0xffff0000
*/
TEXT mappedIvecEnable(SB), $-4
MRC CpMMU, 0, R0, C(CpControl), C(0x0)
ORR $(CpCvivec), R0
MCR CpMMU, 0, R0, C(CpControl), C(0x0)
RET
TEXT mappedIvecDisable(SB), $-4
MRC CpMMU, 0, R0, C(CpControl), C(0x0)
BIC $(CpCvivec), R0
MCR CpMMU, 0, R0, C(CpControl), C(0x0)
RET
/* set the translation table base */
TEXT putdac(SB), $-4
MCR CpMMU, 0, R0, C(CpDAC), C(0x0)
RET
/* set address translation pid */
TEXT putpid(SB), $-4
MCR CpMMU, 0, R0, C(CpPID), C(0x0)
RET
/*
* set the stack value for the mode passed in R0
*/
TEXT setr13(SB), $-4
MOVW 4(FP), R1
MOVW CPSR, R2
BIC $PsrMask, R2, R3
ORR R0, R3
MOVW R3, CPSR
MOVW R13, R0
MOVW R1, R13
MOVW R2, CPSR
RET
/*
* exception vectors, copied by trapinit() to somewhere useful
*/
TEXT vectors(SB), $-4
MOVW 0x18(R15), R15 /* reset */
MOVW 0x18(R15), R15 /* undefined */
MOVW 0x18(R15), R15 /* SWI */
MOVW 0x18(R15), R15 /* prefetch abort */
MOVW 0x18(R15), R15 /* data abort */
MOVW 0x18(R15), R15 /* reserved */
MOVW 0x18(R15), R15 /* IRQ */
MOVW 0x18(R15), R15 /* FIQ */
TEXT vtable(SB), $-4
WORD $_vsvc(SB) /* reset, in svc mode already */
WORD $_vund(SB) /* undefined, switch to svc mode */
WORD $_vsvc(SB) /* swi, in svc mode already */
WORD $_vpabt(SB) /* prefetch abort, switch to svc mode */
WORD $_vdabt(SB) /* data abort, switch to svc mode */
WORD $_vsvc(SB) /* reserved */
WORD $_virq(SB) /* IRQ, switch to svc mode */
WORD $_vfiq(SB) /* FIQ, switch to svc mode */
TEXT _vrst(SB), $-4
BL resettrap(SB)
TEXT _vsvc(SB), $-4 /* SWI */
MOVW.W R14, -4(R13) /* ureg->pc = interupted PC */
MOVW SPSR, R14 /* ureg->psr = SPSR */
MOVW.W R14, -4(R13) /* ... */
MOVW $PsrMsvc, R14 /* ureg->type = PsrMsvc */
MOVW.W R14, -4(R13) /* ... */
MOVM.DB.W.S [R0-R14], (R13) /* save user level registers, at end r13 points to ureg */
MOVW $setR12(SB), R12 /* Make sure we've got the kernel's SB loaded */
MOVW R13, R0 /* first arg is pointer to ureg */
SUB $8, R13 /* space for argument+link */
BL syscall(SB)
ADD $(8+4*15), R13 /* make r13 point to ureg->type */
MOVW 8(R13), R14 /* restore link */
MOVW 4(R13), R0 /* restore SPSR */
MOVW R0, SPSR /* ... */
MOVM.DB.S (R13), [R0-R14] /* restore registers */
ADD $8, R13 /* pop past ureg->{type+psr} */
RFE /* MOVM.IA.S.W (R13), [R15] */
TEXT _vund(SB), $-4 /* undefined */
MOVM.IA [R0-R4], (R13) /* free some working space */
MOVW $PsrMund, R0
B _vswitch
TEXT _vpabt(SB), $-4 /* prefetch abort */
MOVM.IA [R0-R4], (R13) /* free some working space */
MOVW $PsrMabt, R0 /* r0 = type */
B _vswitch
TEXT _vdabt(SB), $-4 /* prefetch abort */
MOVM.IA [R0-R4], (R13) /* free some working space */
MOVW $(PsrMabt+1), R0 /* r0 = type */
B _vswitch
TEXT _virq(SB), $-4 /* IRQ */
MOVM.IA [R0-R4], (R13) /* free some working space */
MOVW $PsrMirq, R0 /* r0 = type */
B _vswitch
/*
* come here with type in R0 and R13 pointing above saved [r0-r4]
* and type in r0. we'll switch to SVC mode and then call trap.
*/
_vswitch:
MOVW SPSR, R1 /* save SPSR for ureg */
MOVW R14, R2 /* save interrupted pc for ureg */
MOVW R13, R3 /* save pointer to where the original [R0-R3] are */
/* switch to svc mode */
MOVW CPSR, R14
BIC $PsrMask, R14
ORR $(PsrDirq|PsrDfiq|PsrMsvc), R14
MOVW R14, CPSR
/* interupted code kernel or user? */
AND.S $0xf, R1, R4
BEQ _userexcep
/* here for trap from SVC mode */
MOVM.DB.W [R0-R2], (R13) /* set ureg->{type, psr, pc}; r13 points to ureg->type */
MOVM.IA (R3), [R0-R4] /* restore [R0-R4] from previous mode's stack */
MOVM.DB.W [R0-R14], (R13) /* save kernel level registers, at end r13 points to ureg */
MOVW $setR12(SB), R12 /* Make sure we've got the kernel's SB loaded */
MOVW R13, R0 /* first arg is pointer to ureg */
SUB $8, R13 /* space for argument+link (for debugger) */
MOVW $0xdeaddead,R11 /* marker */
BL trap(SB)
ADD $(8+4*15), R13 /* make r13 point to ureg->type */
MOVW 8(R13), R14 /* restore link */
MOVW 4(R13), R0 /* restore SPSR */
MOVW R0, SPSR /* ... */
MOVM.DB (R13), [R0-R14] /* restore registers */
ADD $8, R13 /* pop past ureg->{type+psr} */
RFE /* MOVM.IA.S.W (R13), [R15] */
/* here for trap from USER mode */
_userexcep:
MOVM.DB.W [R0-R2], (R13) /* set ureg->{type, psr, pc}; r13 points to ureg->type */
MOVM.IA (R3), [R0-R4] /* restore [R0-R4] from previous mode's stack */
MOVM.DB.W.S [R0-R14], (R13) /* save kernel level registers, at end r13 points to ureg */
MOVW $setR12(SB), R12 /* Make sure we've got the kernel's SB loaded */
MOVW R13, R0 /* first arg is pointer to ureg */
SUB $8, R13 /* space for argument+link (for debugger) */
BL trap(SB)
ADD $(8+4*15), R13 /* make r13 point to ureg->type */
MOVW 8(R13), R14 /* restore link */
MOVW 4(R13), R0 /* restore SPSR */
MOVW R0, SPSR /* ... */
MOVM.DB.S (R13), [R0-R14] /* restore registers */
ADD $8, R13 /* pop past ureg->{type+psr} */
RFE /* MOVM.IA.S.W (R13), [R15] */
TEXT _vfiq(SB), $-4 /* FIQ */
RFE /* FIQ is special, ignore it for now */
/*
* This is the first jump from kernel to user mode.
* Fake a return from interrupt.
*
* Enter with R0 containing the user stack pointer.
* UTZERO + 0x20 is always the entry point.
*
*/
TEXT touser(SB),$-4
/* store the user stack pointer into the USR_r13 */
MOVM.DB.W [R0], (R13)
MOVM.S.IA.W (R13),[R13]
/* set up a PSR for user level */
MOVW $(PsrMusr), R0
MOVW R0,SPSR
/* save the PC on the stack */
MOVW $(UTZERO+0x20), R0
MOVM.DB.W [R0],(R13)
/* return from interrupt */
RFE /* MOVM.IA.S.W (R13), [R15] */
/*
* here to jump to a newly forked process
*/
TEXT forkret(SB),$-4
ADD $(4*15), R13 /* make r13 point to ureg->type */
MOVW 8(R13), R14 /* restore link */
MOVW 4(R13), R0 /* restore SPSR */
MOVW R0, SPSR /* ... */
MOVM.DB.S (R13), [R0-R14] /* restore registers */
ADD $8, R13 /* pop past ureg->{type+psr} */
RFE /* MOVM.IA.S.W (R13), [R15] */
TEXT splhi(SB), $-4
/* save caller pc in Mach */
MOVW $(MACHADDR+0x04),R2
MOVW R14,0(R2)
/* turn off interrupts */
MOVW CPSR, R0
ORR $(PsrDfiq|PsrDirq), R0, R1
MOVW R1, CPSR
RET
TEXT spllo(SB), $-4
MOVW CPSR, R0
BIC $(PsrDfiq|PsrDirq), R0, R1
MOVW R1, CPSR
RET
TEXT splx(SB), $-4
/* save caller pc in Mach */
MOVW $(MACHADDR+0x04),R2
MOVW R14,0(R2)
/* reset interrupt level */
MOVW R0, R1
MOVW CPSR, R0
MOVW R1, CPSR
RET
TEXT splxpc(SB), $-4 /* for iunlock */
MOVW R0, R1
MOVW CPSR, R0
MOVW R1, CPSR
RET
TEXT spldone(SB), $0
RET
TEXT islo(SB), $-4
MOVW CPSR, R0
AND $(PsrDfiq|PsrDirq), R0
EOR $(PsrDfiq|PsrDirq), R0
RET
TEXT cpsrr(SB), $-4
MOVW CPSR, R0
RET
TEXT spsrr(SB), $-4
MOVW SPSR, R0
RET
TEXT getcallerpc(SB), $-4
MOVW 0(R13), R0
RET
TEXT tas(SB), $-4
MOVW R0, R1
MOVW $0xDEADDEAD, R2
SWPW R2, (R1), R0
RET
TEXT setlabel(SB), $-4
MOVW R13, 0(R0) /* sp */
MOVW R14, 4(R0) /* pc */
MOVW $0, R0
RET
TEXT gotolabel(SB), $-4
MOVW 0(R0), R13 /* sp */
MOVW 4(R0), R14 /* pc */
MOVW $1, R0
RET
/* The first MCR instruction of this function needs to be on a cache-line
* boundary; to make this happen, it will be copied (in trap.c).
*
* Doze puts the machine into idle mode. Any interrupt will get it out
* at the next instruction (the RET, to be precise).
*/
TEXT _doze(SB), $-4
MOVW $UCDRAMZERO, R1
MOVW R0,R0
MOVW R0,R0
MOVW R0,R0
MOVW R0,R0
MOVW R0,R0
MOVW R0,R0
MOVW R0,R0
MCR CpPWR, 0, R0, C(CpTest), C(0x2), 2
MOVW (R1), R0
MCR CpPWR, 0, R0, C(CpTest), C(0x8), 2
RET