Files
Arquivotheca.SunOS-4.1.4/sys/boot/sparc/srt0.s
seta75D ff309bfe1c Init
2021-10-11 18:37:13 -03:00

382 lines
8.7 KiB
ArmAsm

/*
* srt0.s - standalone startup code
* .seg "data"
* .asciz "@(#)srt0.s 1.1 94/10/31"
* Copyright (c) 1986 by Sun Microsystems, Inc.
*/
.seg "text"
.align 4
#include <machine/asm_linkage.h>
#include <machine/param.h>
#include <machine/reg.h>
#include <machine/psl.h>
#include <machine/trap.h>
#include <machine/mmu.h>
#include <mon/idprom.h>
/*
* param.h defines VAC, DELAY, and CDELAY
* if we are compiling for the bootblock undef VAC
* to save on code size
*/
#ifdef BOOTBLOCK
#undef VAC
#endif
/*
* Initial interrupt priority and how to get there.
*/
#define PSR_PIL_SHIFT 8
#define PSR_PIL_INIT (13 << PSR_PIL_SHIFT)
/*
* The following variables are machine-dependent and are set in fiximp.
*/
.seg "data"
.global _Cpudelay
/*
* This variable is used in usec_delay(). See the chart in lib/sparc/misc.s.
* Srt0.s sets this value based on the actual runtime environment encountered.
* It's critical that the value be no SMALLER than required, e.g. the
* DELAY macro guarantees a MINIMUM delay, not a maximum.
*/
_Cpudelay: ! count down counter initial value
#define CPUDELAY_DEFAULT 7
.word CPUDELAY_DEFAULT ! worst case value (33 Mhz)
.global _nwindows
_nwindows:
#define NWINDOWS_DEFAULT 8
.word NWINDOWS_DEFAULT ! max # windows...mustn't be too small
.global _npmgrps
_npmgrps:
#define NPMGRPS_DEFAULT 512
.word NPMGRPS_DEFAULT ! max # pmegs
.global _vac
_vac:
#define VAC_DEFAULT 1
.word VAC_DEFAULT ! vac is there by default
.global _vac_size
_vac_size:
#define VACSIZE_DEFAULT 0x20000
.word VACSIZE_DEFAULT ! 128K
.global _vac_linesize
_vac_linesize:
#define VACLINESIZE_DEFAULT 16
.word VACLINESIZE_DEFAULT
.global _segmask
_segmask:
#define SEGMASK_DEFAULT 0x1ff
.word SEGMASK_DEFAULT ! segmask is 511 by default
.global _romp
/*
* The following variables are more or less machine-independent
* (or are set outside of fiximp).
*/
_romp:
.word 0
.global _cpudelay ! old macros:
_cpudelay: ! shift right amount to scale (n << 4)
.word 0 ! worst case value (25 Mhz)
idp:
.word 0 ! room for idprom format & mach type
.word 0
.global _environ
_environ:
.word 0 ! satisfy references from libc
exitbuf:
.skip 5*4 ! (jump_buf)exitbuf for _exit routine
.seg "text"
.align 8
.global _end
.global _edata
.global __setjmp
.global __longjmp
.global _main
.global __exit
.global __exitto
.global _start
_start:
#ifdef BOOTBLOCK
.global _begin, _bootb, _bbsize, _bbchecksum
b,a _begin
_bootb:
! should be NBLKENTRIES (64), see installboot.c
.skip 64*4 ! room for boot_tab
_bbsize: .word 0
_bbchecksum: .word 0
_begin:
#endif BOOTBLOCK
! Each standalone program is responsible for its own stack. Our strategy
! is that each program which uses this runtime code creates a stack just
! below its relocation address. Previous windows may (and probably do)
! have frames allocated on the prior stack; leave them alone. Starting with
! this window, allocate our own stack frames for our windows. (Overflows
! or a window flush would then pass seamlessly from our stack to the old.)
! RESTRICTION: A program running at some relocation address must not exec
! another which will run at the very same address: the stacks would collide.
! This is currently not a problem, as all standalone programs (boot, copy,
! kadb, unix, et al.) run at different, carefully chosen addresses...which
! is, of course, a crock.
!
! Careful: don't touch %o0 until the save, since it holds the romp
! for Forth PROMs.
!
set _start, %o1
save %o1, -SA(MINFRAME), %sp
acall:
call 1f ! get the current pc into o7
! (where _start is currently located)
sethi %hi(acall), %o3 ! relocated address of call
1:
sub %o7,acall-_start,%o0 ! address where _start is in memory
or %o3, %lo(acall), %o3 ! relocated address of call
cmp %o3, %o7
be jmpstart
.empty ! next instruction ok in delay slot
set _edata+4, %o2 ! end of program, inclusive, except bss
set _start, %o1 ! beginning of program
sub %o2, %o1, %o2 ! size of program
2:
ldd [%o0], %o4 ! relocate program
inc 8, %o0 ! bcopy
std %o4, [%o1]
deccc 8, %o2
bg 2b
inc 8, %o1
set jmpstart, %l0 ! now that it is relocated, jump to it
jmp %l0
nop
jmpstart:
set _romp, %o0 ! Stash the romp we've been saving
st %i0, [%o0]
/*
* We need to read idprom to figure out what we are.
* Put machine-dependent variables in the following registers:
* %l0 Cpudelay
* %l1 nwindows
* %l2 npmgrps
* %l3 vac
* %l4 vac_size
* %l5 vac_linesize
*/
fiximp:
set idp, %o0
call _getidprom
mov 2, %o1
cmp %o0, IDFORM_1
mov VACLINESIZE_DEFAULT, %l5
sethi %hi(VACSIZE_DEFAULT), %l4
mov VAC_DEFAULT, %l3
mov NPMGRPS_DEFAULT, %l2
mov NWINDOWS_DEFAULT, %l1
bne id_badformat
mov CPUDELAY_DEFAULT, %l0
set idp, %o1
ldub [%o1+1], %o0
#ifdef sun4
cmp %o0, IDM_SUN4
be id_sunrise ! Sunrise?
cmp %o0, IDM_SUN4_COBRA
be id_cobra ! Cobra?
cmp %o0, IDM_SUN4_STINGRAY
be id_stingray ! Stingray?
cmp %o0, IDM_SUN4_SUNRAY
be id_sunray ! Sunray?
nop
id_cobra:
set _segmask, %o1
set 0xff, %o2
st %o2, [%o1] ! set segmask to 0xff
mov 7, %l0 ! set Cpudelay to 7
mov NPMGRPS_110, %l2 ! set npmgrps
mov %g0, %l3 ! set vac to zero
ba set_delay
.empty ! use delay slot to set nwindows
/*
* All of the Cpudelay values used are for cache off.
*/
id_sunrise:
mov 7, %l1 ! set nwindows to 7
mov NPMGRPS_260, %l2 ! set npmgrps
ba set_delay
mov 1, %l0 ! set Cpudelay to 1
id_stingray:
mov 7, %l1 ! set nwindows to 7
mov NPMGRPS_330, %l2 ! set npmgrps
ba set_delay
mov 1, %l0 ! set Cpudelay to 1
id_sunray:
mov NPMGRPS_460, %l2 ! set npmgrps
mov VAC_LINESIZE_SUNRAY, %l5
mov 1, %l0 ! set Cpudelay to 1
#else sun4
/*
* XXX - This should all come from the open prom properties.
*/
mov 1, %l0 ! set Cpudelay to 1
cmp %o0, IDM_SUN4C_60
be id_campus1 ! Campus-1?
cmp %o0, IDM_SUN4C_40
be id_campus1 ! Office-1?
cmp %o0, IDM_SUN4C_65
be,a id_campus1 ! Campus-B?
mov 1, %l0 ! set Cpudelay to 1
cmp %o0, IDM_SUN4C_20
be id_campus1 ! Off-campus?
cmp %o0, IDM_SUN4C_70
be,a id_calvin ! Calvin?
mov 1, %l0 ! set Cpudelay to 1
id_campus1:
mov 7, %l1 ! set nwindows to 7
mov NPMGRPS_60, %l2 ! set npmgrps
sethi %hi(VAC_SIZE_60), %l4
mov VAC_LINESIZE_60, %l5
ba set_delay
mov %g0, %l3 ! set vac to zero
id_calvin:
mov 8, %l1 ! set nwindows to 8
mov 256, %l2 ! set npmgrps
sethi %hi(VAC_SIZE_60*2), %l4
mov VAC_LINESIZE_60*2, %l5
mov %g0, %l3 ! set vac to zero
#endif sun4
id_badformat:
set_delay:
sethi %hi(_Cpudelay), %o0
st %l0, [%o0 + %lo(_Cpudelay)] ! set Cpudelay
sethi %hi(_nwindows), %o0
st %l1, [%o0 + %lo(_nwindows)] ! set nwindows
sethi %hi(_npmgrps), %o0
st %l2, [%o0 + %lo(_npmgrps)] ! set npmgrps
sethi %hi(_vac), %o0
st %l3, [%o0 + %lo(_vac)] ! set vac
sethi %hi(_vac_size), %o0
st %l3, [%o0 + %lo(_vac_size)]
sethi %hi(_vac_linesize), %o0
#ifdef VAC
call init_cache
#endif
st %l3, [%o0 + %lo(_vac_linesize)]
set _edata, %o0 ! beginning of bss
set _end+4, %o1 ! end of bss
call _bzero ! zero the bss
sub %o1, %o0, %o1 ! size of bss
!
! Set the psr into a known state, until we are sure it is:
! supervisor mode, interrupt level >= 13, traps enabled
!
mov %psr, %o0
andn %o0, PSR_PIL, %o0
set PSR_S|PSR_PIL_INIT|PSR_ET, %o1
or %o0, %o1, %o0
mov %o0, %psr
nop; nop; nop
#ifdef sun4c
call _l14enable ! turn on level 14 interrupts
nop
#endif !sun4c
!
! Mark this spot.
!
sethi %hi(exitbuf), %o0
call __setjmp
or %o0, %lo(exitbuf), %o0
tst %o0 ! returned 1: we exit now.
bnz out
nop
call _main
mov 0, %o0 ! delay slot
! Fall through...
!
! __exit means exit NOW. We may be arbitrarily deep in the windows, so longjmp.
!
#ifndef VAC
__exit:
set exitbuf, %o0
call __longjmp
mov 1, %o1
out:
ret ! ret to prom
restore
__exitto:
save %sp, -SA(MINFRAME), %sp
set _romp, %o0 ! pass the romp to the callee
jmpl %i0, %o7 ! call thru register
ld [%o0], %o0
ret
restore
#else !VAC
__exit:
save %sp, -SA(MINFRAME), %sp
set _vac, %o0 ! check vac flag
ld [%o0], %o0
tst %o0
bz 1f
call _turnoff_cache
nop
1:
set exitbuf, %o0
call __longjmp
mov 1, %o1
out:
ret
restore
__exitto:
save %sp, -SA(MINFRAME), %sp
!
! turn off the cache if it's currently on
!
set _vac, %o0 ! check vac flag
ld [%o0], %o0
tst %o0
bz no_cache
nop
call _turnoff_cache
nop
no_cache:
set _romp, %o0 ! pass the romp to the callee
jmpl %i0, %o7 ! call thru register
ld [%o0], %o0
set _vac, %o0 ! check vac flag
ld [%o0], %o0
tst %o0
bz leave_cache_off
nop
call _turnon_cache
nop
leave_cache_off:
ret
restore
init_cache:
save %sp, -SA(MINFRAME), %sp
set _vac, %o0 ! check vac flag
ld [%o0], %o0
tst %o0
bz 1f
.empty
set _start, %o0 ! this doesn't get the stack
sethi %hi(_end), %o1
call _cache_prog ! clear the NC bits for prog's pages
or %o1, %lo(_end), %o1
call _turnon_cache
nop
1:
ret
restore
#endif VAC