libc/libgloss/sparc_leon/locore.S

171 lines
4.1 KiB
ArmAsm

/*
* Copyright (c) 2011 Aeroflex Gaisler
*
* BSD license:
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/* The traptable has to be the first code in a boot PROM. */
#include <asm-leon/head.h>
#define TRAP(H) mov %psr, %l0; sethi %hi(H), %l4; jmp %l4+%lo(H); nop;
#define TRAPL(H) nop; sethi %hi(H), %g1; jmp %g1+%lo(H); nop;
#define TRAP_ENTRY(H) rd %psr, %l0; b H; rd %wim, %l3; nop;
#define WIM_INIT 2
#ifdef _SOFT_FLOAT
#define PSR_INIT 0x0e0
#else
#define PSR_INIT 0x10e0
#endif
#define NUMREGWINDOWS 8
/* Unexcpected trap will halt the processor by forcing it to error state */
#define BAD_TRAP ta 0; nop; nop; nop;
/* Software trap. Treat as BAD_TRAP */
#define SOFT_TRAP BAD_TRAP
.seg "text"
.global _trap_table, start, _start, cpuinit, leonbare_irq_entry, _hardreset
.global _window_overflow, _window_underflow, _flush_windows, _fpdis_enable
/*.global _nwindows, _leon_version, _nwindows_min1*/
!
! Startup code for standalone system. Wash IU and FPU (if present) registers.
! The registers have to be written to initiate the parity bits.
!
.section .text
/* ------- */
.weak _hardreset
.set _hardreset,_hardreset_libgloss
/* ------- */
.global _hardreset_custom_weak, _hardreset_real, _cleanregs_custom_weak, _hardreset_custom_svt_weak
_hardreset_real:
nop
_hardreset_libgloss:
set _hardreset_custom_weak, %g1 ! possible mkprom init code here, default links to dummy _hardreset_custom_dummy
call %g1
nop
set _trap_table, %g1 ! Initialize TBR
mov %g1, %tbr
set _hardreset_custom_svt_weak, %g1 ! give mkprom svt chance to reset tbr
call %g1
nop
set _cleanregs_custom_weak, %g1
call %g1
nop
#ifdef _FLAT
mov %g0, %wim
#else
/* ! assume that %sp is correct use cwp of psr to set the next window as invalid
mov %psr, %g2 ! extract cwp
and 0x1f, %g2,%g2
set 0x1, %g3
sll %g3,%g2,%g3 ! the bit mask for cwp
sll %g3, 1, %g4 ! rotate one to left
sethi %hi(_nwindows_min1), %g5 ! NWINDOWS-1
ld [%g5+%lo(_nwindows_min1)], %g5
srl %g3, %g5, %g5
or %g5, %g4, %g5
mov %g5, %wim
nop; nop; nop */
#endif
/*
mov %psr, %g2
set 0x202, %g3
sll %g3, %g2, %g2
mov %g2, %wim
nop; nop; nop
1:
*/
! -------------------------------
! only cpu 0 initializes
/* mov %psr, %g5
srl %g5, 24, %g5
and %g5, 3, %g5
subcc %g5, 3, %g0 ! leon2: 0 or 2, leon3: 3
bne callcpuinit
nop
*/
rd %asr17,%g5
srl %g5,28,%g5
cmp %g5,%g0
bne slavego
nop
callcpuinit:
call cpuinit
nop
call pnpinit
nop
slavego:
! -------------------------------
sub %sp, 0x40, %sp ! room for main to save args
call _start
nop
mov 1, %g1
ta 0 ! Halt if _main would return ...
nop
.global _fpdis,_fpdis_svt
_fpdis_svt:
_fpdis:
set 0x1000, %l4
andcc %l0, %l4, %l3
bne,a 4f
andn %l0, %l4, %l0
ta 0
4:
mov %l0, %psr ! restore %psr
nop; nop; nop
jmp %l2 ! Jump to nPC
rett %l2 + 4
/*
!''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
.section .bss
.global _nwindows, _leon_version, _nwindows_min1
_nwindows:
.word 8
_nwindows_min1:
.word 7
_leon_version:
.word 3
*/