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uboot-1.1.4-kirkwood/cpu/mpc8260/start.S

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u-boot 1.1.4
2024-01-07 23:57:24 +01:00
/*
* Copyright (C) 1998 Dan Malek <dmalek@jlc.net>
* Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
* Copyright (C) 2000, 2001,2002 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
*/
/*
* U-Boot - Startup Code for MPC8260 PowerPC based Embedded Boards
*/
#include <config.h>
#include <mpc8260.h>
#include <version.h>
#define CONFIG_8260 1 /* needed for Linux kernel header files */
#define _LINUX_CONFIG_H 1 /* avoid reading Linux autoconf.h file */
#include <ppc_asm.tmpl>
#include <ppc_defs.h>
#include <asm/cache.h>
#include <asm/mmu.h>
#ifndef CONFIG_IDENT_STRING
#define CONFIG_IDENT_STRING ""
#endif
/* We don't want the MMU yet.
*/
#undef MSR_KERNEL
/* Floating Point enable, Machine Check and Recoverable Interr. */
#ifdef DEBUG
#define MSR_KERNEL (MSR_FP|MSR_RI)
#else
#define MSR_KERNEL (MSR_FP|MSR_ME|MSR_RI)
#endif
/*
* Set up GOT: Global Offset Table
*
* Use r14 to access the GOT
*/
START_GOT
GOT_ENTRY(_GOT2_TABLE_)
GOT_ENTRY(_FIXUP_TABLE_)
GOT_ENTRY(_start)
GOT_ENTRY(_start_of_vectors)
GOT_ENTRY(_end_of_vectors)
GOT_ENTRY(transfer_to_handler)
GOT_ENTRY(__init_end)
GOT_ENTRY(_end)
GOT_ENTRY(__bss_start)
#if defined(CONFIG_HYMOD)
GOT_ENTRY(environment)
#endif
END_GOT
/*
* Version string - must be in data segment because MPC8260 uses the first
* 256 bytes for the Hard Reset Configuration Word table (see below).
* Similarly, can't have the U-Boot Magic Number as the first thing in
* the image - don't know how this will affect the image tools, but I guess
* I'll find out soon
*/
.data
.globl version_string
version_string:
.ascii U_BOOT_VERSION
.ascii " (", __DATE__, " - ", __TIME__, ")"
.ascii CONFIG_IDENT_STRING, "\0"
/*
* Hard Reset Configuration Word (HRCW) table
*
* The Hard Reset Configuration Word (HRCW) sets a number of useful things
* such as whether there is an external memory controller, whether the
* PowerPC core is disabled (i.e. only the communications processor is
* active, accessed by another CPU on the bus), whether using external
* arbitration, external bus mode, boot port size, core initial prefix,
* internal space base, boot memory space, etc.
*
* These things dictate where the processor begins execution, where the
* boot ROM appears in memory, the memory controller setup when access
* boot ROM, etc. The HRCW is *extremely* important.
*
* The HRCW is read from the bus during reset. One CPU on the bus will
* be a hard reset configuration master, any others will be hard reset
* configuration slaves. The master reads eight HRCWs from flash during
* reset - the first it uses for itself, the other 7 it communicates to
* up to 7 configuration slaves by some complicated mechanism, which is
* not really important here.
*
* The configuration master performs 32 successive reads starting at address
* 0 and incrementing by 8 each read (i.e. on 64 bit boundaries) but only 8
* bits is read, and always from byte lane D[0-7] (so that port size of the
* boot device does not matter). The first four reads form the 32 bit HRCW
* for the master itself. The second four reads form the HRCW for the first
* slave, and so on, up to seven slaves. The 32 bit HRCW is formed by
* concatenating the four bytes, with the first read placed in byte 0 (the
* most significant byte), and so on with the fourth read placed in byte 3
* (the least significant byte).
*/
#define _HRCW_TABLE_ENTRY(w) \
.fill 8,1,(((w)>>24)&0xff); \
.fill 8,1,(((w)>>16)&0xff); \
.fill 8,1,(((w)>> 8)&0xff); \
.fill 8,1,(((w) )&0xff)
.text
.globl _hrcw_table
_hrcw_table:
_HRCW_TABLE_ENTRY(CFG_HRCW_MASTER)
_HRCW_TABLE_ENTRY(CFG_HRCW_SLAVE1)
_HRCW_TABLE_ENTRY(CFG_HRCW_SLAVE2)
_HRCW_TABLE_ENTRY(CFG_HRCW_SLAVE3)
_HRCW_TABLE_ENTRY(CFG_HRCW_SLAVE4)
_HRCW_TABLE_ENTRY(CFG_HRCW_SLAVE5)
_HRCW_TABLE_ENTRY(CFG_HRCW_SLAVE6)
_HRCW_TABLE_ENTRY(CFG_HRCW_SLAVE7)
/*
* After configuration, a system reset exception is executed using the
* vector at offset 0x100 relative to the base set by MSR[IP]. If MSR[IP]
* is 0, the base address is 0x00000000. If MSR[IP] is 1, the base address
* is 0xfff00000. In the case of a Power On Reset or Hard Reset, the value
* of MSR[IP] is determined by the CIP field in the HRCW.
*
* Other bits in the HRCW set up the Base Address and Port Size in BR0.
* This determines the location of the boot ROM (flash or EPROM) in the
* processor's address space at boot time. As long as the HRCW is set up
* so that we eventually end up executing the code below when the processor
* executes the reset exception, the actual values used should not matter.
*
* Once we have got here, the address mask in OR0 is cleared so that the
* bottom 32K of the boot ROM is effectively repeated all throughout the
* processor's address space, after which we can jump to the absolute
* address at which the boot ROM was linked at compile time, and proceed
* to initialise the memory controller without worrying if the rug will be
* pulled out from under us, so to speak (it will be fine as long as we
* configure BR0 with the same boot ROM link address).
*/
. = EXC_OFF_SYS_RESET
.globl _start
_start:
li r21, BOOTFLAG_COLD /* Normal Power-On: Boot from FLASH*/
nop
b boot_cold
. = EXC_OFF_SYS_RESET + 0x10
.globl _start_warm
_start_warm:
li r21, BOOTFLAG_WARM /* Software reboot */
b boot_warm
boot_cold:
#if defined(CONFIG_MPC8260ADS) && defined(CFG_DEFAULT_IMMR)
lis r3, CFG_DEFAULT_IMMR@h
nop
lwz r4, 0(r3)
nop
rlwinm r4, r4, 0, 8, 5
nop
oris r4, r4, 0x0200
nop
stw r4, 0(r3)
nop
#endif /* CONFIG_MPC8260ADS && CFG_DEFAULT_IMMR */
boot_warm:
mfmsr r5 /* save msr contents */
#if defined(CONFIG_COGENT)
/* this is what the cogent EPROM does */
li r0, 0
mtmsr r0
isync
bl cogent_init_8260
#endif /* CONFIG_COGENT */
#if defined(CFG_DEFAULT_IMMR)
lis r3, CFG_IMMR@h
ori r3, r3, CFG_IMMR@l
lis r4, CFG_DEFAULT_IMMR@h
stw r3, 0x1A8(r4)
#endif /* CFG_DEFAULT_IMMR */
/* Initialise the MPC8260 processor core */
/*--------------------------------------------------------------*/
bl init_8260_core
#ifndef CFG_RAMBOOT
/* When booting from ROM (Flash or EPROM), clear the */
/* Address Mask in OR0 so ROM appears everywhere */
/*--------------------------------------------------------------*/
lis r3, (CFG_IMMR+IM_REGBASE)@h
lwz r4, IM_OR0@l(r3)
li r5, 0x7fff
and r4, r4, r5
stw r4, IM_OR0@l(r3)
/* Calculate absolute address in FLASH and jump there */
/*--------------------------------------------------------------*/
lis r3, CFG_MONITOR_BASE@h
ori r3, r3, CFG_MONITOR_BASE@l
addi r3, r3, in_flash - _start + EXC_OFF_SYS_RESET
mtlr r3
blr
in_flash:
#endif /* CFG_RAMBOOT */
/* initialize some things that are hard to access from C */
/*--------------------------------------------------------------*/
lis r3, CFG_IMMR@h /* set up stack in internal DPRAM */
ori r1, r3, CFG_INIT_SP_OFFSET
li r0, 0 /* Make room for stack frame header and */
stwu r0, -4(r1) /* clear final stack frame so that */
stwu r0, -4(r1) /* stack backtraces terminate cleanly */
/* let the C-code set up the rest */
/* */
/* Be careful to keep code relocatable ! */
/*--------------------------------------------------------------*/
GET_GOT /* initialize GOT access */
/* r3: IMMR */
bl cpu_init_f /* run low-level CPU init code (in Flash)*/
#ifdef DEBUG
bl init_debug /* set up debugging stuff */
#endif
mr r3, r21
/* r3: BOOTFLAG */
bl board_init_f /* run 1st part of board init code (in Flash)*/
/*
* Vector Table
*/
.globl _start_of_vectors
_start_of_vectors:
/* Machine check */
STD_EXCEPTION(0x200, MachineCheck, MachineCheckException)
/* Data Storage exception. */
STD_EXCEPTION(0x300, DataStorage, UnknownException)
/* Instruction Storage exception. */
STD_EXCEPTION(0x400, InstStorage, UnknownException)
/* External Interrupt exception. */
STD_EXCEPTION(0x500, ExtInterrupt, external_interrupt)
/* Alignment exception. */
. = 0x600
Alignment:
EXCEPTION_PROLOG
mfspr r4,DAR
stw r4,_DAR(r21)
mfspr r5,DSISR
stw r5,_DSISR(r21)
addi r3,r1,STACK_FRAME_OVERHEAD
li r20,MSR_KERNEL
rlwimi r20,r23,0,16,16 /* copy EE bit from saved MSR */
rlwimi r20,r23,0,25,25 /* copy IP bit from saved MSR */
lwz r6,GOT(transfer_to_handler)
mtlr r6
blrl
.L_Alignment:
.long AlignmentException - _start + EXC_OFF_SYS_RESET
.long int_return - _start + EXC_OFF_SYS_RESET
/* Program check exception */
. = 0x700
ProgramCheck:
EXCEPTION_PROLOG
addi r3,r1,STACK_FRAME_OVERHEAD
li r20,MSR_KERNEL
rlwimi r20,r23,0,16,16 /* copy EE bit from saved MSR */
rlwimi r20,r23,0,25,25 /* copy IP bit from saved MSR */
lwz r6,GOT(transfer_to_handler)
mtlr r6
blrl
.L_ProgramCheck:
.long ProgramCheckException - _start + EXC_OFF_SYS_RESET
.long int_return - _start + EXC_OFF_SYS_RESET
STD_EXCEPTION(0x800, FPUnavailable, UnknownException)
/* I guess we could implement decrementer, and may have
* to someday for timekeeping.
*/
STD_EXCEPTION(0x900, Decrementer, timer_interrupt)
STD_EXCEPTION(0xa00, Trap_0a, UnknownException)
STD_EXCEPTION(0xb00, Trap_0b, UnknownException)
STD_EXCEPTION(0xc00, SystemCall, UnknownException)
STD_EXCEPTION(0xd00, SingleStep, UnknownException)
STD_EXCEPTION(0xe00, Trap_0e, UnknownException)
STD_EXCEPTION(0xf00, Trap_0f, UnknownException)
STD_EXCEPTION(0x1000, InstructionTLBMiss, UnknownException)
STD_EXCEPTION(0x1100, DataLoadTLBMiss, UnknownException)
STD_EXCEPTION(0x1200, DataStoreTLBMiss, UnknownException)
#ifdef DEBUG
. = 0x1300
/*
* This exception occurs when the program counter matches the
* Instruction Address Breakpoint Register (IABR).
*
* I want the cpu to halt if this occurs so I can hunt around
* with the debugger and look at things.
*
* When DEBUG is defined, both machine check enable (in the MSR)
* and checkstop reset enable (in the reset mode register) are
* turned off and so a checkstop condition will result in the cpu
* halting.
*
* I force the cpu into a checkstop condition by putting an illegal
* instruction here (at least this is the theory).
*
* well - that didnt work, so just do an infinite loop!
*/
1: b 1b
#else
STD_EXCEPTION(0x1300, InstructionBreakpoint, DebugException)
#endif
STD_EXCEPTION(0x1400, SMI, UnknownException)
STD_EXCEPTION(0x1500, Trap_15, UnknownException)
STD_EXCEPTION(0x1600, Trap_16, UnknownException)
STD_EXCEPTION(0x1700, Trap_17, UnknownException)
STD_EXCEPTION(0x1800, Trap_18, UnknownException)
STD_EXCEPTION(0x1900, Trap_19, UnknownException)
STD_EXCEPTION(0x1a00, Trap_1a, UnknownException)
STD_EXCEPTION(0x1b00, Trap_1b, UnknownException)
STD_EXCEPTION(0x1c00, Trap_1c, UnknownException)
STD_EXCEPTION(0x1d00, Trap_1d, UnknownException)
STD_EXCEPTION(0x1e00, Trap_1e, UnknownException)
STD_EXCEPTION(0x1f00, Trap_1f, UnknownException)
STD_EXCEPTION(0x2000, Trap_20, UnknownException)
STD_EXCEPTION(0x2100, Trap_21, UnknownException)
STD_EXCEPTION(0x2200, Trap_22, UnknownException)
STD_EXCEPTION(0x2300, Trap_23, UnknownException)
STD_EXCEPTION(0x2400, Trap_24, UnknownException)
STD_EXCEPTION(0x2500, Trap_25, UnknownException)
STD_EXCEPTION(0x2600, Trap_26, UnknownException)
STD_EXCEPTION(0x2700, Trap_27, UnknownException)
STD_EXCEPTION(0x2800, Trap_28, UnknownException)
STD_EXCEPTION(0x2900, Trap_29, UnknownException)
STD_EXCEPTION(0x2a00, Trap_2a, UnknownException)
STD_EXCEPTION(0x2b00, Trap_2b, UnknownException)
STD_EXCEPTION(0x2c00, Trap_2c, UnknownException)
STD_EXCEPTION(0x2d00, Trap_2d, UnknownException)
STD_EXCEPTION(0x2e00, Trap_2e, UnknownException)
STD_EXCEPTION(0x2f00, Trap_2f, UnknownException)
.globl _end_of_vectors
_end_of_vectors:
. = 0x3000
/*
* This code finishes saving the registers to the exception frame
* and jumps to the appropriate handler for the exception.
* Register r21 is pointer into trap frame, r1 has new stack pointer.
*/
.globl transfer_to_handler
transfer_to_handler:
stw r22,_NIP(r21)
lis r22,MSR_POW@h
andc r23,r23,r22
stw r23,_MSR(r21)
SAVE_GPR(7, r21)
SAVE_4GPRS(8, r21)
SAVE_8GPRS(12, r21)
SAVE_8GPRS(24, r21)
mflr r23
andi. r24,r23,0x3f00 /* get vector offset */
stw r24,TRAP(r21)
li r22,0
stw r22,RESULT(r21)
lwz r24,0(r23) /* virtual address of handler */
lwz r23,4(r23) /* where to go when done */
mtspr SRR0,r24
mtspr SRR1,r20
mtlr r23
SYNC
rfi /* jump to handler, enable MMU */
int_return:
mfmsr r28 /* Disable interrupts */
li r4,0
ori r4,r4,MSR_EE
andc r28,r28,r4
SYNC /* Some chip revs need this... */
mtmsr r28
SYNC
lwz r2,_CTR(r1)
lwz r0,_LINK(r1)
mtctr r2
mtlr r0
lwz r2,_XER(r1)
lwz r0,_CCR(r1)
mtspr XER,r2
mtcrf 0xFF,r0
REST_10GPRS(3, r1)
REST_10GPRS(13, r1)
REST_8GPRS(23, r1)
REST_GPR(31, r1)
lwz r2,_NIP(r1) /* Restore environment */
lwz r0,_MSR(r1)
mtspr SRR0,r2
mtspr SRR1,r0
lwz r0,GPR0(r1)
lwz r2,GPR2(r1)
lwz r1,GPR1(r1)
SYNC
rfi
#if defined(CONFIG_COGENT)
/*
* This code initialises the MPC8260 processor core
* (conforms to PowerPC 603e spec)
*/
.globl cogent_init_8260
cogent_init_8260:
/* Taken from page 14 of CMA282 manual */
/*--------------------------------------------------------------*/
lis r4, (CFG_IMMR+IM_REGBASE)@h
lis r3, CFG_IMMR@h
stw r3, IM_IMMR@l(r4)
lwz r3, IM_IMMR@l(r4)
stw r3, 0(r0)
lis r3, CFG_SYPCR@h
ori r3, r3, CFG_SYPCR@l
stw r3, IM_SYPCR@l(r4)
lwz r3, IM_SYPCR@l(r4)
stw r3, 4(r0)
lis r3, CFG_SCCR@h
ori r3, r3, CFG_SCCR@l
stw r3, IM_SCCR@l(r4)
lwz r3, IM_SCCR@l(r4)
stw r3, 8(r0)
/* the rest of this was disassembled from the */
/* EPROM code that came with my CMA282 CPU module */
/*--------------------------------------------------------------*/
lis r1, 0x1234
ori r1, r1, 0x5678
stw r1, 0x20(r0)
lwz r1, 0x20(r0)
stw r1, 0x24(r0)
lwz r1, 0x24(r0)
lis r3, 0x0e80
ori r3, r3, 0
stw r1, 4(r3)
lwz r1, 4(r3)
/* Done! */
/*--------------------------------------------------------------*/
blr
#endif /* CONFIG_COGENT */
/*
* This code initialises the MPC8260 processor core
* (conforms to PowerPC 603e spec)
* Note: expects original MSR contents to be in r5.
*/
.globl init_8260_core
init_8260_core:
/* Initialize machine status; enable machine check interrupt */
/*--------------------------------------------------------------*/
li r3, MSR_KERNEL /* Set ME and RI flags */
rlwimi r3, r5, 0, 25, 25 /* preserve IP bit set by HRCW */
#ifdef DEBUG
rlwimi r3, r5, 0, 21, 22 /* debugger might set SE & BE bits */
#endif
SYNC /* Some chip revs need this... */
mtmsr r3
SYNC
mtspr SRR1, r3 /* Make SRR1 match MSR */
/* Initialise the SYPCR early, and reset the watchdog (if req) */
/*--------------------------------------------------------------*/
lis r3, (CFG_IMMR+IM_REGBASE)@h
#if !defined(CONFIG_COGENT)
lis r4, CFG_SYPCR@h
ori r4, r4, CFG_SYPCR@l
stw r4, IM_SYPCR@l(r3)
#endif /* !CONFIG_COGENT */
#if defined(CONFIG_WATCHDOG)
li r4, 21868 /* = 0x556c */
sth r4, IM_SWSR@l(r3)
li r4, -21959 /* = 0xaa39 */
sth r4, IM_SWSR@l(r3)
#endif /* CONFIG_WATCHDOG */
/* Initialize the Hardware Implementation-dependent Registers */
/* HID0 also contains cache control */
/*--------------------------------------------------------------*/
lis r3, CFG_HID0_INIT@h
ori r3, r3, CFG_HID0_INIT@l
SYNC
mtspr HID0, r3
lis r3, CFG_HID0_FINAL@h
ori r3, r3, CFG_HID0_FINAL@l
SYNC
mtspr HID0, r3
lis r3, CFG_HID2@h
ori r3, r3, CFG_HID2@l
mtspr HID2, r3
/* clear all BAT's */
/*--------------------------------------------------------------*/
li r0, 0
mtspr DBAT0U, r0
mtspr DBAT0L, r0
mtspr DBAT1U, r0
mtspr DBAT1L, r0
mtspr DBAT2U, r0
mtspr DBAT2L, r0
mtspr DBAT3U, r0
mtspr DBAT3L, r0
mtspr IBAT0U, r0
mtspr IBAT0L, r0
mtspr IBAT1U, r0
mtspr IBAT1L, r0
mtspr IBAT2U, r0
mtspr IBAT2L, r0
mtspr IBAT3U, r0
mtspr IBAT3L, r0
SYNC
/* invalidate all tlb's */
/* */
/* From the 603e User Manual: "The 603e provides the ability to */
/* invalidate a TLB entry. The TLB Invalidate Entry (tlbie) */
/* instruction invalidates the TLB entry indexed by the EA, and */
/* operates on both the instruction and data TLBs simultaneously*/
/* invalidating four TLB entries (both sets in each TLB). The */
/* index corresponds to bits 15-19 of the EA. To invalidate all */
/* entries within both TLBs, 32 tlbie instructions should be */
/* issued, incrementing this field by one each time." */
/* */
/* "Note that the tlbia instruction is not implemented on the */
/* 603e." */
/* */
/* bits 15-19 correspond to addresses 0x00000000 to 0x0001F000 */
/* incrementing by 0x1000 each time. The code below is sort of */
/* based on code in "flush_tlbs" from arch/ppc/kernel/head.S */
/* */
/*--------------------------------------------------------------*/
li r3, 32
mtctr r3
li r3, 0
1: tlbie r3
addi r3, r3, 0x1000
bdnz 1b
SYNC
/* Done! */
/*--------------------------------------------------------------*/
blr
#ifdef DEBUG
/*
* initialise things related to debugging.
*
* must be called after the global offset table (GOT) is initialised
* (GET_GOT) and after cpu_init_f() has executed.
*/
.globl init_debug
init_debug:
lis r3, (CFG_IMMR+IM_REGBASE)@h
/* Quick and dirty hack to enable the RAM and copy the */
/* vectors so that we can take exceptions. */
/*--------------------------------------------------------------*/
/* write Memory Refresh Prescaler */
li r4, CFG_MPTPR
sth r4, IM_MPTPR@l(r3)
/* write 60x Refresh Timer */
li r4, CFG_PSRT
stb r4, IM_PSRT@l(r3)
/* init the 60x SDRAM Mode Register */
lis r4, (CFG_PSDMR|PSDMR_OP_NORM)@h
ori r4, r4, (CFG_PSDMR|PSDMR_OP_NORM)@l
stw r4, IM_PSDMR@l(r3)
/* write Precharge All Banks command */
lis r4, (CFG_PSDMR|PSDMR_OP_PREA)@h
ori r4, r4, (CFG_PSDMR|PSDMR_OP_PREA)@l
stw r4, IM_PSDMR@l(r3)
stb r0, 0(0)
/* write eight CBR Refresh commands */
lis r4, (CFG_PSDMR|PSDMR_OP_CBRR)@h
ori r4, r4, (CFG_PSDMR|PSDMR_OP_CBRR)@l
stw r4, IM_PSDMR@l(r3)
stb r0, 0(0)
stb r0, 0(0)
stb r0, 0(0)
stb r0, 0(0)
stb r0, 0(0)
stb r0, 0(0)
stb r0, 0(0)
stb r0, 0(0)
/* write Mode Register Write command */
lis r4, (CFG_PSDMR|PSDMR_OP_MRW)@h
ori r4, r4, (CFG_PSDMR|PSDMR_OP_MRW)@l
stw r4, IM_PSDMR@l(r3)
stb r0, 0(0)
/* write Normal Operation command and enable Refresh */
lis r4, (CFG_PSDMR|PSDMR_OP_NORM|PSDMR_RFEN)@h
ori r4, r4, (CFG_PSDMR|PSDMR_OP_NORM|PSDMR_RFEN)@l
stw r4, IM_PSDMR@l(r3)
stb r0, 0(0)
/* RAM should now be operational */
#define VEC_WRD_CNT ((_end_of_vectors - _start + EXC_OFF_SYS_RESET) / 4)
lwz r3, GOT(_end_of_vectors)
rlwinm r4, r3, 0, 18, 31 /* _end_of_vectors & 0x3FFF */
lis r5, VEC_WRD_CNT@h
ori r5, r5, VEC_WRD_CNT@l
mtctr r5
1:
lwzu r5, -4(r3)
stwu r5, -4(r4)
bdnz 1b
/* Load the Instruction Address Breakpoint Register (IABR). */
/* */
/* The address to load is stored in the first word of dual port */
/* ram and should be preserved while the power is on, so you */
/* can plug addresses into that location then reset the cpu and */
/* this code will load that address into the IABR after the */
/* reset. */
/* */
/* When the program counter matches the contents of the IABR, */
/* an exception is generated (before the instruction at that */
/* location completes). The vector for this exception is 0x1300 */
/*--------------------------------------------------------------*/
lis r3, CFG_IMMR@h
lwz r3, 0(r3)
mtspr IABR, r3
/* Set the entire dual port RAM (where the initial stack */
/* resides) to a known value - makes it easier to see where */
/* the stack has been written */
/*--------------------------------------------------------------*/
lis r3, (CFG_IMMR + CFG_INIT_SP_OFFSET)@h
ori r3, r3, (CFG_IMMR + CFG_INIT_SP_OFFSET)@l
li r4, ((CFG_INIT_SP_OFFSET - 4) / 4)
mtctr r4
lis r4, 0xdeadbeaf@h
ori r4, r4, 0xdeadbeaf@l
1:
stwu r4, -4(r3)
bdnz 1b
/* Done! */
/*--------------------------------------------------------------*/
blr
#endif
/* Cache functions.
*
* Note: requires that all cache bits in
* HID0 are in the low half word.
*/
.globl icache_enable
icache_enable:
mfspr r3, HID0
ori r3, r3, HID0_ICE
lis r4, 0
ori r4, r4, HID0_ILOCK
andc r3, r3, r4
ori r4, r3, HID0_ICFI
isync
mtspr HID0, r4 /* sets enable and invalidate, clears lock */
isync
mtspr HID0, r3 /* clears invalidate */
blr
.globl icache_disable
icache_disable:
mfspr r3, HID0
lis r4, 0
ori r4, r4, HID0_ICE|HID0_ILOCK
andc r3, r3, r4
ori r4, r3, HID0_ICFI
isync
mtspr HID0, r4 /* sets invalidate, clears enable and lock */
isync
mtspr HID0, r3 /* clears invalidate */
blr
.globl icache_status
icache_status:
mfspr r3, HID0
rlwinm r3, r3, HID0_ICE_BITPOS + 1, 31, 31
blr
.globl dcache_enable
dcache_enable:
mfspr r3, HID0
ori r3, r3, HID0_DCE
lis r4, 0
ori r4, r4, HID0_DLOCK
andc r3, r3, r4
ori r4, r3, HID0_DCI
sync
mtspr HID0, r4 /* sets enable and invalidate, clears lock */
sync
mtspr HID0, r3 /* clears invalidate */
blr
.globl dcache_disable
dcache_disable:
mfspr r3, HID0
lis r4, 0
ori r4, r4, HID0_DCE|HID0_DLOCK
andc r3, r3, r4
ori r4, r3, HID0_DCI
sync
mtspr HID0, r4 /* sets invalidate, clears enable and lock */
sync
mtspr HID0, r3 /* clears invalidate */
blr
.globl dcache_status
dcache_status:
mfspr r3, HID0
rlwinm r3, r3, HID0_DCE_BITPOS + 1, 31, 31
blr
.globl get_pvr
get_pvr:
mfspr r3, PVR
blr
/*------------------------------------------------------------------------------*/
/*
* void relocate_code (addr_sp, gd, addr_moni)
*
* This "function" does not return, instead it continues in RAM
* after relocating the monitor code.
*
* r3 = dest
* r4 = src
* r5 = length in bytes
* r6 = cachelinesize
*/
.globl relocate_code
relocate_code:
mr r1, r3 /* Set new stack pointer */
mr r9, r4 /* Save copy of Global Data pointer */
mr r10, r5 /* Save copy of Destination Address */
mr r3, r5 /* Destination Address */
lis r4, CFG_MONITOR_BASE@h /* Source Address */
ori r4, r4, CFG_MONITOR_BASE@l
lwz r5, GOT(__init_end)
sub r5, r5, r4
li r6, CFG_CACHELINE_SIZE /* Cache Line Size */
/*
* Fix GOT pointer:
*
* New GOT-PTR = (old GOT-PTR - CFG_MONITOR_BASE) + Destination Address
*
* Offset:
*/
sub r15, r10, r4
/* First our own GOT */
add r14, r14, r15
/* then the one used by the C code */
add r30, r30, r15
/*
* Now relocate code
*/
cmplw cr1,r3,r4
addi r0,r5,3
srwi. r0,r0,2
beq cr1,4f /* In place copy is not necessary */
beq 7f /* Protect against 0 count */
mtctr r0
bge cr1,2f
la r8,-4(r4)
la r7,-4(r3)
1: lwzu r0,4(r8)
stwu r0,4(r7)
bdnz 1b
b 4f
2: slwi r0,r0,2
add r8,r4,r0
add r7,r3,r0
3: lwzu r0,-4(r8)
stwu r0,-4(r7)
bdnz 3b
/*
* Now flush the cache: note that we must start from a cache aligned
* address. Otherwise we might miss one cache line.
*/
4: cmpwi r6,0
add r5,r3,r5
beq 7f /* Always flush prefetch queue in any case */
subi r0,r6,1
andc r3,r3,r0
mfspr r7,HID0 /* don't do dcbst if dcache is disabled */
rlwinm r7,r7,HID0_DCE_BITPOS+1,31,31
cmpwi r7,0
beq 9f
mr r4,r3
5: dcbst 0,r4
add r4,r4,r6
cmplw r4,r5
blt 5b
sync /* Wait for all dcbst to complete on bus */
9: mfspr r7,HID0 /* don't do icbi if icache is disabled */
rlwinm r7,r7,HID0_ICE_BITPOS+1,31,31
cmpwi r7,0
beq 7f
mr r4,r3
6: icbi 0,r4
add r4,r4,r6
cmplw r4,r5
blt 6b
7: sync /* Wait for all icbi to complete on bus */
isync
/*
* We are done. Do not return, instead branch to second part of board
* initialization, now running from RAM.
*/
addi r0, r10, in_ram - _start + EXC_OFF_SYS_RESET
mtlr r0
blr
in_ram:
/*
* Relocation Function, r14 point to got2+0x8000
*
* Adjust got2 pointers, no need to check for 0, this code
* already puts a few entries in the table.
*/
li r0,__got2_entries@sectoff@l
la r3,GOT(_GOT2_TABLE_)
lwz r11,GOT(_GOT2_TABLE_)
mtctr r0
sub r11,r3,r11
addi r3,r3,-4
1: lwzu r0,4(r3)
add r0,r0,r11
stw r0,0(r3)
bdnz 1b
/*
* Now adjust the fixups and the pointers to the fixups
* in case we need to move ourselves again.
*/
2: li r0,__fixup_entries@sectoff@l
lwz r3,GOT(_FIXUP_TABLE_)
cmpwi r0,0
mtctr r0
addi r3,r3,-4
beq 4f
3: lwzu r4,4(r3)
lwzux r0,r4,r11
add r0,r0,r11
stw r10,0(r3)
stw r0,0(r4)
bdnz 3b
4:
clear_bss:
/*
* Now clear BSS segment
*/
lwz r3,GOT(__bss_start)
#if defined(CONFIG_HYMOD)
/*
* For HYMOD - the environment is the very last item in flash.
* The real .bss stops just before environment starts, so only
* clear up to that point.
*
* taken from mods for FADS board
*/
lwz r4,GOT(environment)
#else
lwz r4,GOT(_end)
#endif
cmplw 0, r3, r4
beq 6f
li r0, 0
5:
stw r0, 0(r3)
addi r3, r3, 4
cmplw 0, r3, r4
bne 5b
6:
mr r3, r9 /* Global Data pointer */
mr r4, r10 /* Destination Address */
bl board_init_r
/*
* Copy exception vector code to low memory
*
* r3: dest_addr
* r7: source address, r8: end address, r9: target address
*/
.globl trap_init
trap_init:
lwz r7, GOT(_start)
lwz r8, GOT(_end_of_vectors)
li r9, 0x100 /* reset vector always at 0x100 */
cmplw 0, r7, r8
bgelr /* return if r7>=r8 - just in case */
mflr r4 /* save link register */
1:
lwz r0, 0(r7)
stw r0, 0(r9)
addi r7, r7, 4
addi r9, r9, 4
cmplw 0, r7, r8
bne 1b
/*
* relocate `hdlr' and `int_return' entries
*/
li r7, .L_MachineCheck - _start + EXC_OFF_SYS_RESET
li r8, Alignment - _start + EXC_OFF_SYS_RESET
2:
bl trap_reloc
addi r7, r7, 0x100 /* next exception vector */
cmplw 0, r7, r8
blt 2b
li r7, .L_Alignment - _start + EXC_OFF_SYS_RESET
bl trap_reloc
li r7, .L_ProgramCheck - _start + EXC_OFF_SYS_RESET
bl trap_reloc
li r7, .L_FPUnavailable - _start + EXC_OFF_SYS_RESET
li r8, SystemCall - _start + EXC_OFF_SYS_RESET
3:
bl trap_reloc
addi r7, r7, 0x100 /* next exception vector */
cmplw 0, r7, r8
blt 3b
li r7, .L_SingleStep - _start + EXC_OFF_SYS_RESET
li r8, _end_of_vectors - _start + EXC_OFF_SYS_RESET
4:
bl trap_reloc
addi r7, r7, 0x100 /* next exception vector */
cmplw 0, r7, r8
blt 4b
mfmsr r3 /* now that the vectors have */
lis r7, MSR_IP@h /* relocated into low memory */
ori r7, r7, MSR_IP@l /* MSR[IP] can be turned off */
andc r3, r3, r7 /* (if it was on) */
SYNC /* Some chip revs need this... */
mtmsr r3
SYNC
mtlr r4 /* restore link register */
blr
/*
* Function: relocate entries for one exception vector
*/
trap_reloc:
lwz r0, 0(r7) /* hdlr ... */
add r0, r0, r3 /* ... += dest_addr */
stw r0, 0(r7)
lwz r0, 4(r7) /* int_return ... */
add r0, r0, r3 /* ... += dest_addr */
stw r0, 4(r7)
blr
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