lowlevel_init.S
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/* Memory sub-system initialization code */
#include <config.h>
#include <mach/au1x00.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
#define AU1500_SYS_ADDR 0xB1900000
#define sys_endian 0x0038
#define CP0_Config0 $16
#define MEM_1MS ((396000000/1000000) * 1000)
.text
.set noreorder
.set mips32
.globl lowlevel_init
lowlevel_init:
/*
* Step 1) Establish CPU endian mode.
* NOTE: A fair amount of code is necessary on the Pb1000 to
* obtain the value of Switch S8.1 which is used to determine
* endian at run-time.
*/
/* RCE1 */
li t0, MEM_STCFG1
li t1, 0x00000083
sw t1, 0(t0)
li t0, MEM_STTIME1
li t1, 0x33030A10
sw t1, 0(t0)
li t0, MEM_STADDR1
li t1, 0x11803E40
sw t1, 0(t0)
/* Set DSTRB bits so switch will read correctly */
li t1, 0xBE00000C
lw t2, 0(t1)
or t2, t2, 0x00000300
sw t2, 0(t1)
/* Check switch setting */
li t1, 0xBE000014
lw t2, 0(t1)
and t2, t2, 0x00000100
bne t2, zero, big_endian
nop
little_endian:
/* Change Au1 core to little endian */
li t0, AU1500_SYS_ADDR
li t1, 1
sw t1, sys_endian(t0)
mfc0 t2, CP0_CONFIG
mtc0 t2, CP0_CONFIG
nop
nop
/* Big Endian is default so nothing to do but fall through */
big_endian:
/*
* Step 2) Establish Status Register
* (set BEV, clear ERL, clear EXL, clear IE)
*/
li t1, 0x00400000
mtc0 t1, CP0_STATUS
/*
* Step 3) Establish CP0 Config0
* (set OD, set K0=3)
*/
li t1, 0x00080003
mtc0 t1, CP0_CONFIG
/*
* Step 4) Disable Watchpoint facilities
*/
li t1, 0x00000000
mtc0 t1, CP0_WATCHLO
mtc0 t1, CP0_IWATCHLO
/*
* Step 5) Disable the performance counters
*/
mtc0 zero, CP0_PERFORMANCE
nop
/*
* Step 6) Establish EJTAG Debug register
*/
mtc0 zero, CP0_DEBUG
nop
/*
* Step 7) Establish Cause
* (set IV bit)
*/
li t1, 0x00800000
mtc0 t1, CP0_CAUSE
/* Establish Wired (and Random) */
mtc0 zero, CP0_WIRED
nop
/* First setup pll:s to make serial work ok */
/* We have a 12 MHz crystal */
li t0, SYS_CPUPLL
li t1, 0x21 /* 396 MHz */
sw t1, 0(t0)
sync
nop
nop
/* wait 1mS for clocks to settle */
li t1, MEM_1MS
1: add t1, -1
bne t1, zero, 1b
nop
/* Setup AUX PLL */
li t0, SYS_AUXPLL
li t1, 8 /* 96 MHz */
sw t1, 0(t0) /* aux pll */
sync
/* Static memory controller */
/* RCE0 8MB AMD29D323 Flash */
li t0, MEM_STCFG0
li t1, 0x00001403
sw t1, 0(t0)
li t0, MEM_STTIME0
li t1, 0xFFFFFFDD
sw t1, 0(t0)
li t0, MEM_STADDR0
li t1, 0x11F83FE0
sw t1, 0(t0)
/* RCE1 CPLD Board Logic */
li t0, MEM_STCFG1
li t1, 0x00000083
sw t1, 0(t0)
li t0, MEM_STTIME1
li t1, 0x33030A10
sw t1, 0(t0)
li t0, MEM_STADDR1
li t1, 0x11803E40
sw t1, 0(t0)
/* RCE2 CPLD Board Logic */
li t0, MEM_STCFG2
li t1, 0x00000004
sw t1, 0(t0)
li t0, MEM_STTIME2
li t1, 0x08061908
sw t1, 0(t0)
li t0, MEM_STADDR2
li t1, 0x12A03FC0
sw t1, 0(t0)
/* RCE3 PCMCIA 250ns */
li t0, MEM_STCFG3
li t1, 0x00000002
sw t1, 0(t0)
li t0, MEM_STTIME3
li t1, 0x280E3E07
sw t1, 0(t0)
li t0, MEM_STADDR3
li t1, 0x10000000
sw t1, 0(t0)
sync
/* Set peripherals to a known state */
li t0, IC0_CFG0CLR
li t1, 0xFFFFFFFF
sw t1, 0(t0)
li t0, IC0_CFG0CLR
sw t1, 0(t0)
li t0, IC0_CFG1CLR
sw t1, 0(t0)
li t0, IC0_CFG2CLR
sw t1, 0(t0)
li t0, IC0_SRCSET
sw t1, 0(t0)
li t0, IC0_ASSIGNSET
sw t1, 0(t0)
li t0, IC0_WAKECLR
sw t1, 0(t0)
li t0, IC0_RISINGCLR
sw t1, 0(t0)
li t0, IC0_FALLINGCLR
sw t1, 0(t0)
li t0, IC0_TESTBIT
li t1, 0x00000000
sw t1, 0(t0)
sync
li t0, IC1_CFG0CLR
li t1, 0xFFFFFFFF
sw t1, 0(t0)
li t0, IC1_CFG0CLR
sw t1, 0(t0)
li t0, IC1_CFG1CLR
sw t1, 0(t0)
li t0, IC1_CFG2CLR
sw t1, 0(t0)
li t0, IC1_SRCSET
sw t1, 0(t0)
li t0, IC1_ASSIGNSET
sw t1, 0(t0)
li t0, IC1_WAKECLR
sw t1, 0(t0)
li t0, IC1_RISINGCLR
sw t1, 0(t0)
li t0, IC1_FALLINGCLR
sw t1, 0(t0)
li t0, IC1_TESTBIT
li t1, 0x00000000
sw t1, 0(t0)
sync
li t0, SYS_FREQCTRL0
li t1, 0x00000000
sw t1, 0(t0)
li t0, SYS_FREQCTRL1
li t1, 0x00000000
sw t1, 0(t0)
li t0, SYS_CLKSRC
li t1, 0x00000000
sw t1, 0(t0)
li t0, SYS_PININPUTEN
li t1, 0x00000000
sw t1, 0(t0)
sync
li t0, 0xB1100100
li t1, 0x00000000
sw t1, 0(t0)
li t0, 0xB1400100
li t1, 0x00000000
sw t1, 0(t0)
li t0, SYS_WAKEMSK
li t1, 0x00000000
sw t1, 0(t0)
li t0, SYS_WAKESRC
li t1, 0x00000000
sw t1, 0(t0)
/* wait 1mS before setup */
li t1, MEM_1MS
1: add t1, -1
bne t1, zero, 1b
nop
/*
* Skip memory setup if we are running from memory
*/
li t0, 0x90000000
sub t0, ra, t0
bltz t0, skip_memsetup
nop
/*
* SDCS0 - Not used, for SMROM
* SDCS1 - 32MB Micron 48LCBM16A2
* SDCS2 - 32MB Micron 48LCBM16A2
*/
li t0, MEM_SDMODE0
li t1, 0x00000000
sw t1, 0(t0)
li t0, MEM_SDMODE1
li t1, 0x00552229
sw t1, 0(t0)
li t0, MEM_SDMODE2
li t1, 0x00552229
sw t1, 0(t0)
li t0, MEM_SDADDR0
li t1, 0x00000000
sw t1, 0(t0)
li t0, MEM_SDADDR1
li t1, 0x001003F8
sw t1, 0(t0)
li t0, MEM_SDADDR2
li t1, 0x001023F8
sw t1, 0(t0)
sync
li t0, MEM_SDREFCFG
li t1, 0x74000c30 /* Disable */
sw t1, 0(t0)
sync
li t0, MEM_SDPRECMD
sw zero, 0(t0)
sync
li t0, MEM_SDAUTOREF
sw zero, 0(t0)
sync
sw zero, 0(t0)
sync
li t0, MEM_SDREFCFG
li t1, 0x76000c30 /* Enable */
sw t1, 0(t0)
sync
li t0, MEM_SDWRMD0
li t1, 0x00000023
sw t1, 0(t0)
sync
li t0, MEM_SDWRMD1
li t1, 0x00000023
sw t1, 0(t0)
sync
li t0, MEM_SDWRMD2
li t1, 0x00000023
sw t1, 0(t0)
sync
/* wait 1mS after setup */
li t1, MEM_1MS
1: add t1, -1
bne t1, zero, 1b
nop
skip_memsetup:
li t0, SYS_PINFUNC
li t1, 0/*0x00008080*/
sw t1, 0(t0)
/*
li t0, SYS_TRIOUTCLR
li t1, 0x00001FFF
sw t1, 0(t0)
li t0, SYS_OUTPUTCLR
li t1, 0x00008000
sw t1, 0(t0)
*/
sync
jr ra
nop