u-boot/arch/nds32/cpu/n1213/start.S

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/*
* Andesboot - Startup Code for Whitiger core
*
* Copyright (C) 2006 Andes Technology Corporation
* Copyright (C) 2006 Shawn Lin <nobuhiro@andestech.com>
* Copyright (C) 2011 Macpaul Lin <macpaul@andestech.com>
* Greentime Hu <greentime@andestech.com>
*
* 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 <common.h>
#include <asm/macro.h>
#include <version.h>
/*
* Jump vector table for EVIC mode
*/
#define ENA_DCAC 2UL
#define DIS_DCAC ~ENA_DCAC
#define ICAC_MEM_KBF_ISET (0x07) ! I Cache sets per way
#define ICAC_MEM_KBF_IWAY (0x07<<3) ! I cache ways
#define ICAC_MEM_KBF_ISZ (0x07<<6) ! I cache line size
#define DCAC_MEM_KBF_DSET (0x07) ! D Cache sets per way
#define DCAC_MEM_KBF_DWAY (0x07<<3) ! D cache ways
#define DCAC_MEM_KBF_DSZ (0x07<<6) ! D cache line size
#define PSW $ir0
#define EIT_INTR_PSW $ir1 ! interruption $PSW
#define EIT_PREV_IPSW $ir2 ! previous $IPSW
#define EIT_IVB $ir3 ! intr vector base address
#define EIT_EVA $ir4 ! MMU related Exception VA reg
#define EIT_PREV_EVA $ir5 ! previous $eva
#define EIT_ITYPE $ir6 ! interruption type
#define EIT_PREV_ITYPE $ir7 ! prev intr type
#define EIT_MACH_ERR $ir8 ! machine error log
#define EIT_INTR_PC $ir9 ! Interruption PC
#define EIT_PREV_IPC $ir10 ! previous $IPC
#define EIT_OVL_INTR_PC $ir11 ! overflow interruption PC
#define EIT_PREV_P0 $ir12 ! prev $P0
#define EIT_PREV_P1 $ir13 ! prev $p1
#define CR_ICAC_MEM $cr1 ! I-cache/memory config reg
#define CR_DCAC_MEM $cr2 ! D-cache/memory config reg
#define MR_CAC_CTL $mr8
.globl _start
_start: j reset
j tlb_fill
j tlb_not_present
j tlb_misc
j tlb_vlpt_miss
j machine_error
j debug
j general_exception
j syscall
j internal_interrupt ! H0I
j internal_interrupt ! H1I
j internal_interrupt ! H2I
j internal_interrupt ! H3I
j internal_interrupt ! H4I
j internal_interrupt ! H5I
j software_interrupt ! S0I
.balign 16
/*
* Andesboot Startup Code (reset vector)
*
* 1. bootstrap
* 1.1 reset - start of u-boot
* 1.2 to superuser mode - as is when reset
* 1.4 Do lowlevel_init
* - (this will jump out to lowlevel_init.S in SoC)
* - (lowlevel_init)
* 1.3 Turn off watchdog timer
* - (this will jump out to watchdog.S in SoC)
* - (turnoff_watchdog)
* 2. Do critical init when reboot (not from mem)
* 3. Relocate andesboot to ram
* 4. Setup stack
* 5. Jump to second stage (board_init_r)
*/
/* Note: TEXT_BASE is defined by the (board-dependent) linker script */
.globl _TEXT_BASE
_TEXT_BASE:
.word CONFIG_SYS_TEXT_BASE
/*
* These are defined in the board-specific linker script.
* Subtracting _start from them lets the linker put their
* relative position in the executable instead of leaving
* them null.
*/
#ifdef CONFIG_USE_IRQ
/* IRQ stack memory (calculated at run-time) */
.globl IRQ_STACK_START
IRQ_STACK_START:
.word 0x0badc0de
/* IRQ stack memory (calculated at run-time) */
.globl FIQ_STACK_START
FIQ_STACK_START:
.word 0x0badc0de
#endif
/* IRQ stack memory (calculated at run-time) + 8 bytes */
.globl IRQ_STACK_START_IN
IRQ_STACK_START_IN:
.word 0x0badc0de
/*
* The bootstrap code of nds32 core
*/
reset:
set_ivb:
li $r0, 0x0
/* turn on BTB */
mtsr $r0, $misc_ctl
/* set IVIC, vector size: 4 bytes, base: 0x0 */
mtsr $r0, $ivb
load_lli:
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
jal load_lowlevel_init
jral $p0
#endif
/*
* Set the N1213 (Whitiger) core to superuser mode
* According to spec, it is already when reset
*/
turnoff_wtdog:
#ifndef CONFIG_SKIP_TRUNOFF_WATCHDOG
jal load_turnoff_watchdog
jral $p0
#endif
/*
* Do CPU critical regs init only at reboot,
* not when booting from ram
*/
#ifdef CONFIG_INIT_CRITICAL
bal cpu_init_crit ! Do CPU critical regs init
#endif
/*
* Set stackpointer in internal RAM to call board_init_f
* $sp must be 8-byte alignment for ABI compliance.
*/
call_board_init_f:
li $sp, CONFIG_SYS_INIT_SP_ADDR
li $r0, 0x00000000
#ifdef __PIC__
#ifdef __NDS32_N1213_43U1H__
/* __NDS32_N1213_43U1H__ implies NDS32 V0 ISA */
la $r15, board_init_f ! store function address into $r15
#endif
#endif
j board_init_f ! jump to board_init_f() in lib/board.c
/*
* void relocate_code (addr_sp, gd, addr_moni)
*
* This "function" does not return, instead it continues in RAM
* after relocating the monitor code.
*
*/
.globl relocate_code
relocate_code:
move $r4, $r0 /* save addr_sp */
move $r5, $r1 /* save addr of gd */
move $r6, $r2 /* save addr of destination */
/* Set up the stack */
stack_setup:
move $sp, $r4
la $r0, _start
beq $r0, $r6, clear_bss /* skip relocation */
move $r1, $r6 /* r1 <- scratch for copy_loop */
la $r3, __bss_start
sub $r3, $r3, $r0 /* r3 <- __bss_start_ofs */
add $r2, $r0, $r3 /* r2 <- source end address */
copy_loop:
lwi.p $r7, [$r0], #4
swi.p $r7, [$r1], #4
blt $r0, $r2, copy_loop
/*
* fix relocations related issues
*/
fix_relocations:
l.w $r0, _TEXT_BASE /* r0 <- Text base */
sub $r9, $r6, $r0 /* r9 <- relocation offset */
fix_got:
/*
* 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.
*/
la $r2, __got_start /* r2 <- rel __got_start in FLASH */
add $r2, $r2, $r9 /* r2 <- rel __got_start in RAM */
la $r3, __got_end /* r3 <- rel __got_end in FLASH */
add $r3, $r3, $r9 /* r3 <- rel __got_end in RAM */
addi $r2, $r2, #8 /* skipping first two entries */
fix_got_loop:
lwi $r0, [$r2] /* r0 <- location in FLASH to fix up */
add $r0, $r0, $r9 /* r0 <- location fix up to RAM */
swi.p $r0, [$r2], #4 /* r0 <- store fix into .got in RAM */
blt $r2, $r3, fix_got_loop
clear_bss:
la $r0, __bss_start /* r0 <- rel __bss_start in FLASH */
add $r0, $r0, $r9 /* r0 <- rel __bss_start in FLASH */
la $r1, __bss_end__ /* r1 <- rel __bss_end in RAM */
add $r1, $r1, $r9 /* r0 <- rel __bss_end in RAM */
li $r2, 0x00000000 /* clear */
clbss_l:
sw $r2, [$r0] /* clear loop... */
addi $r0, $r0, #4
bne $r0, $r1, clbss_l
/*
* We are done. Do not return, instead branch to second part of board
* initialization, now running from RAM.
*/
call_board_init_r:
la $r0, board_init_r
move $lp, $r0 /* offset of board_init_r() */
add $lp, $lp, $r9 /* real address of board_init_r() */
/* setup parameters for board_init_r */
move $r0, $r5 /* gd_t */
move $r1, $r6 /* dest_addr */
#ifdef __PIC__
#ifdef __NDS32_N1213_43U1H__ /* NDS32 V0 ISA */
move $r15, $lp /* store function address into $r15 */
#endif
#endif
/* jump to it ... */
jr $lp /* jump to board_init_r() */
/*
* Initialize CPU critical registers
*
* 1. Setup control registers
* 1.1 Mask all IRQs
* 1.2 Flush cache and TLB
* 1.3 Disable MMU and cache
* 2. Setup memory timing
*/
cpu_init_crit:
move $r0, $lp /* push ra */
/* Disable Interrupts by clear GIE in $PSW reg */
setgie.d
/* Flush caches and TLB */
/* Invalidate caches */
bal invalidate_icac
bal invalidate_dcac
/* Flush TLB */
mfsr $p0, $MMU_CFG
andi $p0, $p0, 0x3 ! MMPS
li $p1, 0x2 ! TLB MMU
bne $p0, $p1, 1f
tlbop flushall ! Flush TLB
1:
! Disable MMU, Dcache
! Whitiger is MMU disabled when reset
! Disable the D$
mfsr $p0, MR_CAC_CTL ! Get the $CACHE_CTL reg
li $p1, DIS_DCAC
and $p0, $p0, $p1 ! Set DC_EN bit
mtsr $p0, MR_CAC_CTL ! write back the $CACHE_CTL reg
isb
move $lp, $r0
2:
ret
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
load_lowlevel_init:
la $r6, lowlevel_init
la $r7, load_lli + 4
sub $p0, $r6, $r7
add $p0, $p0, $lp
ret
#endif
#ifndef CONFIG_SKIP_TRUNOFF_WATCHDOG
load_turnoff_watchdog:
la $r6, turnoff_watchdog
la $r7, turnoff_wtdog + 4
sub $p0, $r6, $r7
add $p0, $p0, $lp
ret
#endif
/*
* Invalidate I$
*/
invalidate_icac:
! read $cr1(I CAC/MEM cfg. reg.) configuration
mfsr $t0, CR_ICAC_MEM
! Get the ISZ field
andi $p0, $t0, ICAC_MEM_KBF_ISZ
! if $p0=0, then no I CAC existed
beqz $p0, end_flush_icache
! get $p0 the index of I$ block
srli $p0, $p0, 6
! $t1= bit width of I cache line size(ISZ)
addi $t1, $p0, 2
li $t4, 1
sll $t5, $t4, $t1 ! get $t5 cache line size
andi $p1, $t0, ICAC_MEM_KBF_ISET ! get the ISET field
addi $t2, $p1, 6 ! $t2= bit width of ISET
andi $p1, $t0, ICAC_MEM_KBF_IWAY ! get bitfield of Iway
srli $p1, $p1, 3
addi $p1, $p1, 1 ! then $p1 is I way number
add $t3, $t2, $t1 ! SHIFT
sll $p1, $p1, $t3 ! GET the total cache size
ICAC_LOOP:
sub $p1, $p1, $t5
cctl $p1, L1I_IX_INVAL
bnez $p1, ICAC_LOOP
end_flush_icache:
ret
/*
* Invalidate D$
*/
invalidate_dcac:
! read $cr2(D CAC/MEM cfg. reg.) configuration
mfsr $t0, CR_DCAC_MEM
! Get the DSZ field
andi $p0, $t0, DCAC_MEM_KBF_DSZ
! if $p0=0, then no D CAC existed
beqz $p0, end_flush_dcache
! get $p0 the index of D$ block
srli $p0, $p0, 6
! $t1= bit width of D cache line size(DSZ)
addi $t1, $p0, 2
li $t4, 1
sll $t5, $t4, $t1 ! get $t5 cache line size
andi $p1, $t0, DCAC_MEM_KBF_DSET ! get the DSET field
addi $t2, $p1, 6 ! $t2= bit width of DSET
andi $p1, $t0, DCAC_MEM_KBF_DWAY ! get bitfield of D way
srli $p1, $p1, 3
addi $p1, $p1, 1 ! then $p1 is D way number
add $t3, $t2, $t1 ! SHIFT
sll $p1, $p1, $t3 ! GET the total cache size
DCAC_LOOP:
sub $p1, $p1, $t5
cctl $p1, L1D_IX_INVAL
bnez $p1, DCAC_LOOP
end_flush_dcache:
ret
/*
* Interrupt handling
*/
/*
* exception handlers
*/
.align 5
.macro SAVE_ALL
! FIXME: Other way to get PC?
! FIXME: Update according to the newest spec!!
1:
la $r28, 1
push $r28
mfsr $r28, PSW ! $PSW
push $r28
mfsr $r28, EIT_EVA ! $ir1 $EVA
push $r28
mfsr $r28, EIT_ITYPE ! $ir2 $ITYPE
push $r28
mfsr $r28, EIT_MACH_ERR ! $ir3 Mach Error
push $r28
mfsr $r28, EIT_INTR_PSW ! $ir5 $IPSW
push $r28
mfsr $r28, EIT_PREV_IPSW ! $ir6 prev $IPSW
push $r28
mfsr $r28, EIT_PREV_EVA ! $ir7 prev $EVA
push $r28
mfsr $r28, EIT_PREV_ITYPE ! $ir8 prev $ITYPE
push $r28
mfsr $r28, EIT_INTR_PC ! $ir9 Interruption PC
push $r28
mfsr $r28, EIT_PREV_IPC ! $ir10 prev INTR_PC
push $r28
mfsr $r28, EIT_OVL_INTR_PC ! $ir11 Overflowed INTR_PC
push $r28
mfusr $r28, $d1.lo
push $r28
mfusr $r28, $d1.hi
push $r28
mfusr $r28, $d0.lo
push $r28
mfusr $r28, $d0.hi
push $r28
pushm $r0, $r30 ! store $sp-$r31, ra-$r30, $gp-$r29, $r28-$fp
addi $sp, $sp, -4 ! make room for implicit pt_regs parameters
.endm
.align 5
tlb_fill:
SAVE_ALL
move $r0, $sp ! To get the kernel stack
li $r1, 1 ! Determine interruption type
bal do_interruption
.align 5
tlb_not_present:
SAVE_ALL
move $r0, $sp ! To get the kernel stack
li $r1, 2 ! Determine interruption type
bal do_interruption
.align 5
tlb_misc:
SAVE_ALL
move $r0, $sp ! To get the kernel stack
li $r1, 3 ! Determine interruption type
bal do_interruption
.align 5
tlb_vlpt_miss:
SAVE_ALL
move $r0, $sp ! To get the kernel stack
li $r1, 4 ! Determine interruption type
bal do_interruption
.align 5
machine_error:
SAVE_ALL
move $r0, $sp ! To get the kernel stack
li $r1, 5 ! Determine interruption type
bal do_interruption
.align 5
debug:
SAVE_ALL
move $r0, $sp ! To get the kernel stack
li $r1, 6 ! Determine interruption type
bal do_interruption
.align 5
general_exception:
SAVE_ALL
move $r0, $sp ! To get the kernel stack
li $r1, 7 ! Determine interruption type
bal do_interruption
.align 5
syscall:
SAVE_ALL
move $r0, $sp ! To get the kernel stack
li $r1, 8 ! Determine interruption type
bal do_interruption
.align 5
internal_interrupt:
SAVE_ALL
move $r0, $sp ! To get the kernel stack
li $r1, 9 ! Determine interruption type
bal do_interruption
.align 5
software_interrupt:
SAVE_ALL
move $r0, $sp ! To get the kernel stack
li $r1, 10 ! Determine interruption type
bal do_interruption
.align 5
/*
* void reset_cpu(ulong addr);
* $r0: input address to jump to
*/
.globl reset_cpu
reset_cpu:
/* No need to disable MMU because we never enable it */
bal invalidate_icac
bal invalidate_dcac
mfsr $p0, $MMU_CFG
andi $p0, $p0, 0x3 ! MMPS
li $p1, 0x2 ! TLB MMU
bne $p0, $p1, 1f
tlbop flushall ! Flush TLB
1:
mfsr $p0, MR_CAC_CTL ! Get the $CACHE_CTL reg
li $p1, DIS_DCAC
and $p0, $p0, $p1 ! Clear the DC_EN bit
mtsr $p0, MR_CAC_CTL ! Write back the $CACHE_CTL reg
br $r0 ! Jump to the input address