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/*
* Common Blackfin startup code
*
* Copyright 2004-2008 Analog Devices Inc.
*
* Enter bugs at http://blackfin.uclinux.org/
*
* Licensed under the GPL-2 or later.
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/blackfin.h>
#include <asm/thread_info.h>
#include <asm/trace.h>
__INIT
#define INITIAL_STACK (L1_SCRATCH_START + L1_SCRATCH_LENGTH - 12)
ENTRY(__start)
/* R0: argument of command line string, passed from uboot, save it */
R7 = R0;
/* Enable Cycle Counter and Nesting Of Interrupts */
#ifdef CONFIG_BFIN_SCRATCH_REG_CYCLES
R0 = SYSCFG_SNEN;
#else
R0 = SYSCFG_SNEN | SYSCFG_CCEN;
#endif
SYSCFG = R0;
R0 = 0;
/* Clear Out All the data and pointer Registers */
R1 = R0;
R2 = R0;
R3 = R0;
R4 = R0;
R5 = R0;
R6 = R0;
P0 = R0;
P1 = R0;
P2 = R0;
P3 = R0;
P4 = R0;
P5 = R0;
LC0 = r0;
LC1 = r0;
L0 = r0;
L1 = r0;
L2 = r0;
L3 = r0;
/* Clear Out All the DAG Registers */
B0 = r0;
B1 = r0;
B2 = r0;
B3 = r0;
I0 = r0;
I1 = r0;
I2 = r0;
I3 = r0;
M0 = r0;
M1 = r0;
M2 = r0;
M3 = r0;
trace_buffer_init(p0,r0);
P0 = R1;
R0 = R1;
/* Turn off the icache */
p0.l = LO(IMEM_CONTROL);
p0.h = HI(IMEM_CONTROL);
R1 = [p0];
R0 = ~ENICPLB;
R0 = R0 & R1;
[p0] = R0;
SSYNC;
/* Turn off the dcache */
p0.l = LO(DMEM_CONTROL);
p0.h = HI(DMEM_CONTROL);
R1 = [p0];
R0 = ~ENDCPLB;
R0 = R0 & R1;
[p0] = R0;
SSYNC;
/* Save RETX, in case of doublefault */
p0.l = ___retx;
p0.h = ___retx;
R0 = RETX;
[P0] = R0;
/* Initialize stack pointer */
sp.l = lo(INITIAL_STACK);
sp.h = hi(INITIAL_STACK);
fp = sp;
usp = sp;
#ifdef CONFIG_EARLY_PRINTK
call _init_early_exception_vectors;
#endif
/* Put The Code for PLL Programming and SDRAM Programming in L1 ISRAM */
call _bf53x_relocate_l1_mem;
#ifdef CONFIG_BFIN_KERNEL_CLOCK
call _start_dma_code;
#endif
/* This section keeps the processor in supervisor mode
* during kernel boot. Switches to user mode at end of boot.
* See page 3-9 of Hardware Reference manual for documentation.
*/
/* EVT15 = _real_start */
p0.l = lo(EVT15);
p0.h = hi(EVT15);
p1.l = _real_start;
p1.h = _real_start;
[p0] = p1;
csync;
p0.l = lo(IMASK);
p0.h = hi(IMASK);
p1.l = IMASK_IVG15;
p1.h = 0x0;
[p0] = p1;
csync;
raise 15;
p0.l = .LWAIT_HERE;
p0.h = .LWAIT_HERE;
reti = p0;
#if ANOMALY_05000281
nop; nop; nop;
#endif
rti;
.LWAIT_HERE:
jump .LWAIT_HERE;
ENDPROC(__start)
/* A little BF561 glue ... */
#ifndef WDOG_CTL
# define WDOG_CTL WDOGA_CTL
#endif
ENTRY(_real_start)
/* Enable nested interrupts */
[--sp] = reti;
/* watchdog off for now */
p0.l = lo(WDOG_CTL);
p0.h = hi(WDOG_CTL);
r0 = 0xAD6(z);
w[p0] = r0;
ssync;
/* Zero out the bss region
* Note: this will fail if bss is 0 bytes ...
*/
r0 = 0 (z);
r1.l = ___bss_start;
r1.h = ___bss_start;
r2.l = ___bss_stop;
r2.h = ___bss_stop;
r2 = r2 - r1;
r2 >>= 2;
p1 = r1;
p2 = r2;
lsetup (.L_clear_bss, .L_clear_bss) lc0 = p2;
.L_clear_bss:
[p1++] = r0;
/* In case there is a NULL pointer reference,
* zero out region before stext
*/
p1 = r0;
r2.l = __stext;
r2.h = __stext;
r2 >>= 2;
p2 = r2;
lsetup (.L_clear_zero, .L_clear_zero) lc0 = p2;
.L_clear_zero:
[p1++] = r0;
/* Pass the u-boot arguments to the global value command line */
R0 = R7;
call _cmdline_init;
/* Load the current thread pointer and stack */
sp.l = _init_thread_union;
sp.h = _init_thread_union;
p1 = THREAD_SIZE (z);
sp = sp + p1;
usp = sp;
fp = sp;
jump.l _start_kernel;
ENDPROC(_real_start)
__FINIT
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