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 CPU_SCALE ((CONFIG_SYS_MHZ) / 12) /* CPU clock is a multiple of 12 MHz */
#define MEM_1MS ((CONFIG_SYS_MHZ) * 1000)
.text
.set noreorder
.set mips32
.globl lowlevel_init
lowlevel_init:
/*
* Step 1) Establish CPU endian mode.
* Db1500-specific:
* Switch S1.1 Off(bit7 reads 1) is Little Endian
* Switch S1.1 On (bit7 reads 0) is Big Endian
*/
#ifdef CONFIG_DBAU1550
li t0, MEM_STCFG2
li t1, 0x00000040
sw t1, 0(t0)
li t0, MEM_STTIME2
li t1, 0x22080a20
sw t1, 0(t0)
li t0, MEM_STADDR2
li t1, 0x10c03f00
sw t1, 0(t0)
#else
li t0, MEM_STCFG1
li t1, 0x00000080
sw t1, 0(t0)
li t0, MEM_STTIME1
li t1, 0x22080a20
sw t1, 0(t0)
li t0, MEM_STADDR1
li t1, 0x10c03f00
sw t1, 0(t0)
#endif
li t0, DB1XX0_BCSR_ADDR
lw t1,8(t0)
andi t1,t1,0x80
beq zero,t1,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
#ifdef CONFIG_DBAU1550
/* No workaround if running from ram */
lui t0, 0xffc0
lui t3, 0xbfc0
and t1, ra, t0
bne t1, t3, noCacheJump
nop
/*** From AMD YAMON ***/
/*
* Step 8) Initialize the caches
*/
li t0, (16*1024)
li t1, 32
li t2, 0x80000000
addu t3, t0, t2
cacheloop:
cache 0, 0(t2)
cache 1, 0(t2)
addu t2, t1
bne t2, t3, cacheloop
nop
/* Save return address */
move t3, ra
/* Run from cacheable space now */
bal cachehere
nop
cachehere:
li t1, ~0x20000000 /* convert to KSEG0 */
and t0, ra, t1
addi t0, 5*4 /* 5 insns beyond cachehere */
jr t0
nop
/* Restore return address */
move ra, t3
/*
* Step 9) Initialize the TLB
*/
li t0, 0 # index value
li t1, 0x00000000 # entryhi value
li t2, 32 # 32 entries
tlbloop:
/* Probe TLB for matching EntryHi */
mtc0 t1, CP0_ENTRYHI
tlbp
nop
/* Examine Index[P], 1=no matching entry */
mfc0 t3, CP0_INDEX
li t4, 0x80000000
and t3, t4, t3
addiu t1, t1, 1 # increment t1 (asid)
beq zero, t3, tlbloop
nop
/* Initialize the TLB entry */
mtc0 t0, CP0_INDEX
mtc0 zero, CP0_ENTRYLO0
mtc0 zero, CP0_ENTRYLO1
mtc0 zero, CP0_PAGEMASK
tlbwi
/* Do it again */
addiu t0, t0, 1
bne t0, t2, tlbloop
nop
#endif /* CONFIG_DBAU1550 */
/* First setup pll:s to make serial work ok */
/* We have a 12 MHz crystal */
li t0, SYS_CPUPLL
li t1, CPU_SCALE /* CPU clock */
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, 0x20 /* 96 MHz */
sw t1, 0(t0) /* aux pll */
sync
#ifdef CONFIG_DBAU1550
/* Static memory controller */
/* RCE0 - can not change while fetching, do so from icache */
move t2, ra /* Store return address */
bal getAddr
nop
getAddr:
move t1, ra
move ra, t2 /* Move return addess back */
cache 0x14,0(t1)
cache 0x14,32(t1)
/*** /From YAMON ***/
noCacheJump:
#endif /* CONFIG_DBAU1550 */
#ifdef CONFIG_DBAU1550
li t0, MEM_STTIME0
li t1, 0x040181D7
sw t1, 0(t0)
/* RCE0 AMD MirrorBit Flash (?) */
li t0, MEM_STCFG0
li t1, 0x00000003
sw t1, 0(t0)
li t0, MEM_STADDR0
li t1, 0x11803E00
sw t1, 0(t0)
#else /* CONFIG_DBAU1550 */
li t0, MEM_STTIME0
li t1, 0x040181D7
sw t1, 0(t0)
/* RCE0 AMD 29LV640M MirrorBit Flash */
li t0, MEM_STCFG0
li t1, 0x00000013
sw t1, 0(t0)
li t0, MEM_STADDR0
li t1, 0x11E03F80
sw t1, 0(t0)
#endif /* CONFIG_DBAU1550 */
/* RCE1 CPLD Board Logic */
li t0, MEM_STCFG1
li t1, 0x00000080
sw t1, 0(t0)
li t0, MEM_STTIME1
li t1, 0x22080a20
sw t1, 0(t0)
li t0, MEM_STADDR1
li t1, 0x10c03f00
sw t1, 0(t0)
#ifdef CONFIG_DBAU1550
/* RCE2 CPLD Board Logic */
li t0, MEM_STCFG2
li t1, 0x00000040
sw t1, 0(t0)
li t0, MEM_STTIME2
li t1, 0x22080a20
sw t1, 0(t0)
li t0, MEM_STADDR2
li t1, 0x10c03f00
sw t1, 0(t0)
#else
li t0, MEM_STCFG2
li t1, 0x00000000
sw t1, 0(t0)
li t0, MEM_STTIME2
li t1, 0x00000000
sw t1, 0(t0)
li t0, MEM_STADDR2
li t1, 0x00000000
sw t1, 0(t0)
#endif
/* 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
#ifdef CONFIG_DBAU1550
/* SDCS 0,1,2 DDR SDRAM */
li t0, MEM_SDMODE0
li t1, 0x04276221
sw t1, 0(t0)
li t0, MEM_SDMODE1
li t1, 0x04276221
sw t1, 0(t0)
li t0, MEM_SDMODE2
li t1, 0x04276221
sw t1, 0(t0)
li t0, MEM_SDADDR0
li t1, 0xe21003f0
sw t1, 0(t0)
li t0, MEM_SDADDR1
li t1, 0xe21043f0
sw t1, 0(t0)
li t0, MEM_SDADDR2
li t1, 0xe21083f0
sw t1, 0(t0)
sync
li t0, MEM_SDCONFIGA
li t1, 0x9030060a /* Program refresh - disabled */
sw t1, 0(t0)
sync
li t0, MEM_SDCONFIGB
li t1, 0x00028000
sw t1, 0(t0)
sync
li t0, MEM_SDPRECMD /* Precharge all */
li t1, 0
sw t1, 0(t0)
sync
li t0, MEM_SDWRMD0
li t1, 0x40000000
sw t1, 0(t0)
sync
li t0, MEM_SDWRMD1
li t1, 0x40000000
sw t1, 0(t0)
sync
li t0, MEM_SDWRMD2
li t1, 0x40000000
sw t1, 0(t0)
sync
li t0, MEM_SDWRMD0
li t1, 0x00000063
sw t1, 0(t0)
sync
li t0, MEM_SDWRMD1
li t1, 0x00000063
sw t1, 0(t0)
sync
li t0, MEM_SDWRMD2
li t1, 0x00000063
sw t1, 0(t0)
sync
li t0, MEM_SDPRECMD /* Precharge all */
sw zero, 0(t0)
sync
/* Issue 2 autoref */
li t0, MEM_SDAUTOREF
sw zero, 0(t0)
sync
li t0, MEM_SDAUTOREF
sw zero, 0(t0)
sync
/* Enable refresh */
li t0, MEM_SDCONFIGA
li t1, 0x9830060a /* Program refresh - enabled */
sw t1, 0(t0)
sync
#else /* CONFIG_DBAU1550 */
/* SDCS 0,1 SDRAM */
li t0, MEM_SDMODE0
li t1, 0x005522AA
sw t1, 0(t0)
li t0, MEM_SDMODE1
li t1, 0x005522AA
sw t1, 0(t0)
li t0, MEM_SDMODE2
li t1, 0x00000000
sw t1, 0(t0)
li t0, MEM_SDADDR0
li t1, 0x001003F8
sw t1, 0(t0)
li t0, MEM_SDADDR1
li t1, 0x001023F8
sw t1, 0(t0)
li t0, MEM_SDADDR2
li t1, 0x00000000
sw t1, 0(t0)
sync
li t0, MEM_SDREFCFG
li t1, 0x64000C24 /* 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, 0x66000C24 /* Enable */
sw t1, 0(t0)
sync
li t0, MEM_SDWRMD0
li t1, 0x00000033
sw t1, 0(t0)
sync
li t0, MEM_SDWRMD1
li t1, 0x00000033
sw t1, 0(t0)
sync
#endif /* CONFIG_DBAU1550 */
/* wait 1mS after setup */
li t1, MEM_1MS
1: add t1, -1
bne t1, zero, 1b
nop
li t0, SYS_PINFUNC
li t1, 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