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|
/*
* Startup Code for MIPS32 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 later 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 PARTICULAR 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 Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <asm-offsets.h>
#include <config.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
/*
* 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
.macro setup_c0_status_reset
#ifdef CONFIG_64BIT
setup_c0_status ST0_KX 0
#else
setup_c0_status 0 0
#endif
.endm
#define RVECENT(f,n) \
b f; nop
#define XVECENT(f,bev) \
b f ; \
li k0,bev
.set noreorder
.globl _start
.text
_start:
RVECENT(reset,0) # U-boot entry point
RVECENT(reset,1) # software reboot
#ifdef CONFIG_SYS_XWAY_EBU_BOOTCFG
/*
* Almost all Lantiq XWAY SoC devices have an external bus unit (EBU) to
* access external NOR flashes. If the board boots from NOR flash the
* internal BootROM does a blind read at address 0xB0000010 to read the
* initial configuration for that EBU in order to access the flash
* device with correct parameters. This config option is board-specific.
*/
.word CONFIG_SYS_XWAY_EBU_BOOTCFG
.word 0x00000000
#else
RVECENT(romReserved,2)
#endif
RVECENT(romReserved,3)
RVECENT(romReserved,4)
RVECENT(romReserved,5)
RVECENT(romReserved,6)
RVECENT(romReserved,7)
RVECENT(romReserved,8)
RVECENT(romReserved,9)
RVECENT(romReserved,10)
RVECENT(romReserved,11)
RVECENT(romReserved,12)
RVECENT(romReserved,13)
RVECENT(romReserved,14)
RVECENT(romReserved,15)
RVECENT(romReserved,16)
RVECENT(romReserved,17)
RVECENT(romReserved,18)
RVECENT(romReserved,19)
RVECENT(romReserved,20)
RVECENT(romReserved,21)
RVECENT(romReserved,22)
RVECENT(romReserved,23)
RVECENT(romReserved,24)
RVECENT(romReserved,25)
RVECENT(romReserved,26)
RVECENT(romReserved,27)
RVECENT(romReserved,28)
RVECENT(romReserved,29)
RVECENT(romReserved,30)
RVECENT(romReserved,31)
RVECENT(romReserved,32)
RVECENT(romReserved,33)
RVECENT(romReserved,34)
RVECENT(romReserved,35)
RVECENT(romReserved,36)
RVECENT(romReserved,37)
RVECENT(romReserved,38)
RVECENT(romReserved,39)
RVECENT(romReserved,40)
RVECENT(romReserved,41)
RVECENT(romReserved,42)
RVECENT(romReserved,43)
RVECENT(romReserved,44)
RVECENT(romReserved,45)
RVECENT(romReserved,46)
RVECENT(romReserved,47)
RVECENT(romReserved,48)
RVECENT(romReserved,49)
RVECENT(romReserved,50)
RVECENT(romReserved,51)
RVECENT(romReserved,52)
RVECENT(romReserved,53)
RVECENT(romReserved,54)
RVECENT(romReserved,55)
RVECENT(romReserved,56)
RVECENT(romReserved,57)
RVECENT(romReserved,58)
RVECENT(romReserved,59)
RVECENT(romReserved,60)
RVECENT(romReserved,61)
RVECENT(romReserved,62)
RVECENT(romReserved,63)
XVECENT(romExcHandle,0x200) # bfc00200: R4000 tlbmiss vector
RVECENT(romReserved,65)
RVECENT(romReserved,66)
RVECENT(romReserved,67)
RVECENT(romReserved,68)
RVECENT(romReserved,69)
RVECENT(romReserved,70)
RVECENT(romReserved,71)
RVECENT(romReserved,72)
RVECENT(romReserved,73)
RVECENT(romReserved,74)
RVECENT(romReserved,75)
RVECENT(romReserved,76)
RVECENT(romReserved,77)
RVECENT(romReserved,78)
RVECENT(romReserved,79)
XVECENT(romExcHandle,0x280) # bfc00280: R4000 xtlbmiss vector
RVECENT(romReserved,81)
RVECENT(romReserved,82)
RVECENT(romReserved,83)
RVECENT(romReserved,84)
RVECENT(romReserved,85)
RVECENT(romReserved,86)
RVECENT(romReserved,87)
RVECENT(romReserved,88)
RVECENT(romReserved,89)
RVECENT(romReserved,90)
RVECENT(romReserved,91)
RVECENT(romReserved,92)
RVECENT(romReserved,93)
RVECENT(romReserved,94)
RVECENT(romReserved,95)
XVECENT(romExcHandle,0x300) # bfc00300: R4000 cache vector
RVECENT(romReserved,97)
RVECENT(romReserved,98)
RVECENT(romReserved,99)
RVECENT(romReserved,100)
RVECENT(romReserved,101)
RVECENT(romReserved,102)
RVECENT(romReserved,103)
RVECENT(romReserved,104)
RVECENT(romReserved,105)
RVECENT(romReserved,106)
RVECENT(romReserved,107)
RVECENT(romReserved,108)
RVECENT(romReserved,109)
RVECENT(romReserved,110)
RVECENT(romReserved,111)
XVECENT(romExcHandle,0x380) # bfc00380: R4000 general vector
RVECENT(romReserved,113)
RVECENT(romReserved,114)
RVECENT(romReserved,115)
RVECENT(romReserved,116)
RVECENT(romReserved,116)
RVECENT(romReserved,118)
RVECENT(romReserved,119)
RVECENT(romReserved,120)
RVECENT(romReserved,121)
RVECENT(romReserved,122)
RVECENT(romReserved,123)
RVECENT(romReserved,124)
RVECENT(romReserved,125)
RVECENT(romReserved,126)
RVECENT(romReserved,127)
/*
* We hope there are no more reserved vectors!
* 128 * 8 == 1024 == 0x400
* so this is address R_VEC+0x400 == 0xbfc00400
*/
.align 4
reset:
/* Clear watch registers */
mtc0 zero, CP0_WATCHLO
mtc0 zero, CP0_WATCHHI
/* WP(Watch Pending), SW0/1 should be cleared */
mtc0 zero, CP0_CAUSE
setup_c0_status_reset
/* Init Timer */
mtc0 zero, CP0_COUNT
mtc0 zero, CP0_COMPARE
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
/* CONFIG0 register */
li t0, CONF_CM_UNCACHED
mtc0 t0, CP0_CONFIG
#endif
/* Initialize $gp */
bal 1f
nop
.word _gp
1:
lw gp, 0(ra)
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
/* Initialize any external memory */
la t9, lowlevel_init
jalr t9
nop
/* Initialize caches... */
la t9, mips_cache_reset
jalr t9
nop
/* ... and enable them */
li t0, CONF_CM_CACHABLE_NONCOHERENT
mtc0 t0, CP0_CONFIG
#endif
/* Set up temporary stack */
li t0, CONFIG_SYS_SDRAM_BASE + CONFIG_SYS_INIT_SP_OFFSET
la sp, 0(t0)
la 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
li t0, CONFIG_SYS_MONITOR_BASE
la t3, in_ram
lw t2, -12(t3) # t2 <-- uboot_end_data
move t1, a2
move s2, a2 # s2 <-- destination address
/*
* Fix $gp:
*
* New $gp = (Old $gp - CONFIG_SYS_MONITOR_BASE) + Destination Address
*/
move t6, gp
sub gp, CONFIG_SYS_MONITOR_BASE
add gp, a2 # gp now adjusted
sub s1, gp, t6 # s1 <-- relocation offset
/*
* t0 = source address
* t1 = target address
* t2 = source end address
*/
/*
* Save destination address and size for later usage in flush_cache()
*/
move s0, a1 # save gd in s0
move a0, t1 # a0 <-- destination addr
sub a1, t2, t0 # a1 <-- size
1:
lw t3, 0(t0)
sw t3, 0(t1)
addu t0, 4
ble t0, t2, 1b
addu t1, 4
/* If caches were enabled, we would have to flush them here. */
/* a0 & a1 are already set up for flush_cache(start, size) */
la t9, flush_cache
jalr t9
nop
/* Jump to where we've relocated ourselves */
addi t0, s2, in_ram - _start
jr t0
nop
.word _gp
.word _GLOBAL_OFFSET_TABLE_
.word uboot_end_data
.word uboot_end
.word 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.
*/
lw t3, -4(t0) # t3 <-- num_got_entries
lw t4, -16(t0) # t4 <-- _GLOBAL_OFFSET_TABLE_
lw t5, -20(t0) # t5 <-- _gp
sub t4, t5 # compute offset
add t4, t4, gp # t4 now holds relocated _G_O_T_
addi t4, t4, 8 # skipping first two entries
li t2, 2
1:
lw t1, 0(t4)
beqz t1, 2f
add t1, s1
sw t1, 0(t4)
2:
addi t2, 1
blt t2, t3, 1b
addi t4, 4
/* Clear BSS */
lw t1, -12(t0) # t1 <-- uboot_end_data
lw t2, -8(t0) # t2 <-- uboot_end
add t1, s1 # adjust pointers
add t2, s1
sub t1, 4
1:
addi t1, 4
bltl t1, t2, 1b
sw zero, 0(t1)
move a0, s0 # a0 <-- gd
la t9, board_init_r
jr t9
move a1, s2
.end relocate_code
/* Exception handlers */
romReserved:
b romReserved
romExcHandle:
b romExcHandle
|
