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/*
* Startup Code for MIPS64 CPU-core
*
* Copyright (c) 2003 Wolfgang Denk <wd@denx.de>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any dlater version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICUdlaR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Pdlace, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <asm-offsets.h>
#include <config.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
#ifndef CONFIG_SYS_MIPS_CACHE_MODE
#define CONFIG_SYS_MIPS_CACHE_MODE CONF_CM_CACHABLE_NONCOHERENT
#endif
/*
* For the moment disable interrupts, mark the kernel mode and
* set ST0_KX so that the CPU does not spit fire when using
* 64-bit addresses.
*/
.macro setup_c0_status set clr
.set push
mfc0 t0, CP0_STATUS
or t0, ST0_CU0 | \set | 0x1f | \clr
xor t0, 0x1f | \clr
mtc0 t0, CP0_STATUS
.set noreorder
sll zero, 3 # ehb
.set pop
.endm
.set noreorder
.globl _start
.text
_start:
.org 0x000
b reset
nop
.org 0x080
b romReserved
nop
.org 0x100
b romReserved
nop
.org 0x180
b romReserved
nop
.org 0x200
b romReserved
nop
.org 0x280
b romReserved
nop
.org 0x300
b romReserved
nop
.org 0x380
b romReserved
nop
.org 0x480
b romReserved
nop
/*
* We hope there are no more reserved vectors!
* 128 * 8 == 1024 == 0x400
* so this is address R_VEC+0x400 == 0xbfc00400
*/
.org 0x500
.align 4
reset:
/* Clear watch registers */
dmtc0 zero, CP0_WATCHLO
dmtc0 zero, CP0_WATCHHI
/* WP(Watch Pending), SW0/1 should be cleared */
mtc0 zero, CP0_CAUSE
setup_c0_status ST0_KX 0
/* Init Timer */
mtc0 zero, CP0_COUNT
mtc0 zero, CP0_COMPARE
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
/* CONFIG0 register */
dli t0, CONF_CM_UNCACHED
mtc0 t0, CP0_CONFIG
#endif
/*
* Initialize $gp, force 8 byte alignment of bal instruction to forbid
* the compiler to put nop's between bal and _gp. This is required to
* keep _gp and ra aligned to 8 byte.
*/
.align 3
bal 1f
nop
.dword _gp
1:
ld gp, 0(ra)
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
/* Initialize any external memory */
dla t9, lowlevel_init
jalr t9
nop
/* Initialize caches... */
dla t9, mips_cache_reset
jalr t9
nop
/* ... and enable them */
dli t0, CONFIG_SYS_MIPS_CACHE_MODE
mtc0 t0, CP0_CONFIG
#endif
/* Set up temporary stack */
dli sp, CONFIG_SYS_SDRAM_BASE + CONFIG_SYS_INIT_SP_OFFSET
dla t9, board_init_f
jr t9
nop
/*
* void relocate_code (addr_sp, gd, addr_moni)
*
* This "function" does not return, instead it continues in RAM
* after relocating the monitor code.
*
* a0 = addr_sp
* a1 = gd
* a2 = destination address
*/
.globl relocate_code
.ent relocate_code
relocate_code:
move sp, a0 # set new stack pointer
move s0, a1 # save gd in s0
move s2, a2 # save destination address in s2
dli t0, CONFIG_SYS_MONITOR_BASE
dla t3, in_ram
ld t2, -24(t3) # t2 <-- uboot_end_data
move t1, a2
/*
* Fix $gp:
*
* New $gp = (Old $gp - CONFIG_SYS_MONITOR_BASE) + Destination Address
*/
move t8, gp
dsub gp, CONFIG_SYS_MONITOR_BASE
dadd gp, a2 # gp now adjusted
dsub s1, gp, t8 # s1 <-- relocation offset
/*
* t0 = source address
* t1 = target address
* t2 = source end address
*/
/*
* Save destination address and size for dlater usage in flush_cache()
*/
move a0, t1 # a0 <-- destination addr
dsub a1, t2, t0 # a1 <-- size
1:
lw t3, 0(t0)
sw t3, 0(t1)
daddu t0, 4
blt t0, t2, 1b
daddu t1, 4
/* If caches were enabled, we would have to flush them here. */
/* a0 & a1 are already set up for flush_cache(start, size) */
dla t9, flush_cache
jalr t9
nop
/* Jump to where we've relocated ourselves */
daddi t0, s2, in_ram - _start
jr t0
nop
.dword _gp
.dword _GLOBAL_OFFSET_TABLE_
.dword uboot_end_data
.dword uboot_end
.dword num_got_entries
in_ram:
/*
* Now we want to update GOT.
*
* GOT[0] is reserved. GOT[1] is also reserved for the dynamic object
* generated by GNU ld. Skip these reserved entries from relocation.
*/
ld t3, -8(t0) # t3 <-- num_got_entries
ld t8, -32(t0) # t8 <-- _GLOBAL_OFFSET_TABLE_
ld t9, -40(t0) # t9 <-- _gp
dsub t8, t9 # compute offset
dadd t8, t8, gp # t8 now holds relocated _G_O_T_
daddi t8, t8, 16 # skipping first two entries
dli t2, 2
1:
ld t1, 0(t8)
beqz t1, 2f
dadd t1, s1
sd t1, 0(t8)
2:
daddi t2, 1
blt t2, t3, 1b
daddi t8, 8
/* Clear BSS */
ld t1, -24(t0) # t1 <-- uboot_end_data
ld t2, -16(t0) # t2 <-- uboot_end
dadd t1, s1 # adjust pointers
dadd t2, s1
dsub t1, 8
1:
daddi t1, 8
bltl t1, t2, 1b
sd zero, 0(t1)
move a0, s0 # a0 <-- gd
dla t9, board_init_r
jr t9
move a1, s2
.end relocate_code
/* Exception handlers */
romReserved:
b romReserved
nop
|
