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/* taken from ebfw/rom/dbmentry.s */
#define EB164
/*#ifndef LINT
.data
.asciiz "$Id: dbmentry.s,v 1.1.1.1 1997/10/30 23:27:12 verghese Exp $"
.text
#endif
*/
/*
* Debug Monitor Entry code
*/
#ifndef MAKEDEPEND
#include "ev5_impure.h"
#include "cserve.h"
#include "osf.h"
#endif
//#include "paldefs.h"
#include "regdefs.h"
#include "eb164.h"
//#include "ledcodes.h"
.text
/* return address and padding to octaword align */
#define STARTFRM 16
.globl __start
.ent __start, 0
__start:
_entry:
br t0, 2f # get the current PC
2: ldgp gp, 0(t0) # init gp
#ifdef original_xxm
lda a2, CSERVE_K_RD_IMPURE
call_pal PAL_CSERVE_ENTRY
lda v0, CNS_Q_BASE(v0)
# Add KSEG offset to the impure area
subq zero, 1, t0
sll t0, 42, t0
addq t0, v0, v0
lda t0, CNS_Q_SIGNATURE(v0)
bic t0, 0x07, t0 # Clear bottom 3 bits to avoid
# allignment errors if the
# impure area is total rubbish
ldq t0, 0x00(t0)
srl t0, 16, t0 # Shift signature into bottom 16 bits.
lda t6, 0xDECB(zero) # Load the expected valid signature.
zap t6, 0xFC, t6 # Clear the upper bits.
cmpeq t0, t6, t0 # Is this a valid signature?
beq t0, 1f # Not valid, don't trust input params.
/*
* Init the stack at the first 8K boundary
* below the top of memory.
*/
lda t0, CNS_Q_MEM_SIZE(v0)
ldq t0, 0x00(t0) # Load memory size.
subq t0, 1, t0 # Last address in memory
srl t0, 13, t0 # Align to first 8KB boundary
sll t0, 13, sp # below the top of memory.
br zero, 2f
/*
* If memory size was not passed in via the
* PALcode impure data use the system specific
* MINIMUM_SYSTEM_MEMORY definition.
*/
1:
lda sp, (MINIMUM_SYSTEM_MEMORY&0xffff)(zero)
ldah sp, ((MINIMUM_SYSTEM_MEMORY+0x8000)>>16)(sp)
lda t0, (8*1024)(zero) # Allow for 8KB guard page.
subq sp, t0, sp
2:
#endif /* original_xxm */
/*
* SimOS. Stack pointer is start of a valid phys or KSEG page
*/
bis sp,sp,s0 /* save sp */
slave: lda v0,(8*1024)(sp) /* end of page */
subq zero, 1, t0
sll t0, 42, t0
bis t0, v0, sp
#ifdef original_xxm
# Add KSEG offset to the stack pointer
subq zero, 1, t0
sll t0, 42, t0
addq t0, sp, sp
#endif
lda sp, -STARTFRM(sp) # Create a stack frame
stq ra, 0(sp) # Place return address on the stack
.mask 0x84000000, -8
.frame sp, STARTFRM, ra
/*
* Enable the Floating Point Unit
*/
lda a0, 1(zero)
call_pal PAL_WRFEN_ENTRY
/*
* Every good C program has a main()
*/
beq s0,master
call_pal PAL_WHAMI_ENTRY
bis v0,v0,a0
jsr ra, SlaveLoop
master:
jsr ra, main
/*
* The Debug Monitor should never return.
* However, just incase...
*/
ldgp gp, 0(ra)
bsr zero, _exit
.end __start
.globl _exit
.ent _exit, 0
_exit:
ldq ra, 0(sp) # restore return address
lda sp, STARTFRM(sp) # prune back the stack
ret zero, (ra) # Back from whence we came
.end _exit
.globl cServe
.ent cServe 2
cServe:
.option O1
.frame sp, 0, ra
call_pal PAL_CSERVE_ENTRY
ret zero, (ra)
.end cServe
.globl wrfen
.ent wrfen 2
wrfen:
.option O1
.frame sp, 0, ra
call_pal PAL_WRFEN_ENTRY
ret zero, (ra)
.end wrfen
.globl consoleCallback
.ent consoleCallback 2
consoleCallback:
br t0, 2f # get the current PC
2: ldgp gp, 0(t0) # init gp
lda sp,-64(sp)
stq ra,0(sp)
jsr CallBackDispatcher
ldq ra,0(sp)
lda sp,64(sp)
ret zero,(ra)
.end consoleCallback
.globl consoleFixup
.ent consoleFixup 2
consoleFixup:
br t0, 2f # get the current PC
2: ldgp gp, 0(t0) # init gp
lda sp,-64(sp)
stq ra,0(sp)
jsr CallBackFixup
ldq ra,0(sp)
lda sp,64(sp)
ret zero,(ra)
.end consoleFixup
.globl SpinLock
.ent SpinLock 2
SpinLock:
1:
ldq_l a1,0(a0) # interlock complete lock state
subl ra,3,v0 # get calling addr[31:0] + 1
blbs a1,2f # branch if lock is busy
stq_c v0,0(a0) # attempt to acquire lock
beq v0,2f # branch if lost atomicity
mb # ensure memory coherence
ret zero,(ra) # return to caller (v0 is 1)
2:
br zero,1b
.end SpinLock
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