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/*
* Common Blackfin startup code
*
* Copyright 2004-2008 Analog Devices Inc.
*
* 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>
#include <asm/asm-offsets.h>
__INIT
ENTRY(__init_clear_bss)
r2 = r2 - r1;
cc = r2 == 0;
if cc jump .L_bss_done;
r2 >>= 2;
p1 = r1;
p2 = r2;
lsetup (1f, 1f) lc0 = p2;
1: [p1++] = r0;
.L_bss_done:
rts;
ENDPROC(__init_clear_bss)
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;
/* Optimization register tricks: keep a base value in the
* reserved P registers so we use the load/store with an
* offset syntax. R0 = [P5 + <constant>];
* P5 - core MMR base
* R6 - 0
*/
r6 = 0;
p5.l = 0;
p5.h = hi(COREMMR_BASE);
/* Zero out registers required by Blackfin ABI */
/* Disable circular buffers */
L0 = r6;
L1 = r6;
L2 = r6;
L3 = r6;
/* Disable hardware loops in case we were started by 'go' */
LC0 = r6;
LC1 = r6;
/*
* Clear ITEST_COMMAND and DTEST_COMMAND registers,
* Leaving these as non-zero can confuse the emulator
*/
[p5 + (DTEST_COMMAND - COREMMR_BASE)] = r6;
[p5 + (ITEST_COMMAND - COREMMR_BASE)] = r6;
CSYNC;
trace_buffer_init(p0,r0);
/* Turn off the icache */
r1 = [p5 + (IMEM_CONTROL - COREMMR_BASE)];
BITCLR (r1, ENICPLB_P);
[p5 + (IMEM_CONTROL - COREMMR_BASE)] = r1;
SSYNC;
/* Turn off the dcache */
r1 = [p5 + (DMEM_CONTROL - COREMMR_BASE)];
BITCLR (r1, ENDCPLB_P);
[p5 + (DMEM_CONTROL - COREMMR_BASE)] = r1;
SSYNC;
/* in case of double faults, save a few things */
p1.l = _initial_pda;
p1.h = _initial_pda;
r4 = RETX;
#ifdef CONFIG_DEBUG_DOUBLEFAULT
/* Only save these if we are storing them,
* This happens here, since L1 gets clobbered
* below
*/
GET_PDA(p0, r0);
r0 = [p0 + PDA_DF_RETX];
r1 = [p0 + PDA_DF_DCPLB];
r2 = [p0 + PDA_DF_ICPLB];
r3 = [p0 + PDA_DF_SEQSTAT];
[p1 + PDA_INIT_DF_RETX] = r0;
[p1 + PDA_INIT_DF_DCPLB] = r1;
[p1 + PDA_INIT_DF_ICPLB] = r2;
[p1 + PDA_INIT_DF_SEQSTAT] = r3;
#endif
[p1 + PDA_INIT_RETX] = r4;
/* Initialize stack pointer */
sp.l = _init_thread_union + THREAD_SIZE;
sp.h = _init_thread_union + THREAD_SIZE;
fp = sp;
usp = sp;
#ifdef CONFIG_EARLY_PRINTK
call _init_early_exception_vectors;
r0 = (EVT_IVHW | EVT_IRPTEN | EVT_EVX | EVT_NMI | EVT_RST | EVT_EMU);
sti r0;
#endif
r0 = r6;
/* Zero out all of the fun bss regions */
#if L1_DATA_A_LENGTH > 0
r1.l = __sbss_l1;
r1.h = __sbss_l1;
r2.l = __ebss_l1;
r2.h = __ebss_l1;
call __init_clear_bss
#endif
#if L1_DATA_B_LENGTH > 0
r1.l = __sbss_b_l1;
r1.h = __sbss_b_l1;
r2.l = __ebss_b_l1;
r2.h = __ebss_b_l1;
call __init_clear_bss
#endif
#if L2_LENGTH > 0
r1.l = __sbss_l2;
r1.h = __sbss_l2;
r2.l = __ebss_l2;
r2.h = __ebss_l2;
call __init_clear_bss
#endif
r1.l = ___bss_start;
r1.h = ___bss_start;
r2.l = ___bss_stop;
r2.h = ___bss_stop;
call __init_clear_bss
/* Put The Code for PLL Programming and SDRAM Programming in L1 ISRAM */
call _bfin_relocate_l1_mem;
#ifdef CONFIG_ROMKERNEL
call _bfin_relocate_xip_data;
#endif
#ifdef CONFIG_BFIN_KERNEL_CLOCK
/* Only use on-chip scratch space for stack when absolutely required
* to avoid Anomaly 05000227 ... we know the init_clocks() func only
* uses L1 text and stack space and no other memory region.
*/
# define KERNEL_CLOCK_STACK (L1_SCRATCH_START + L1_SCRATCH_LENGTH - 12)
sp.l = lo(KERNEL_CLOCK_STACK);
sp.h = hi(KERNEL_CLOCK_STACK);
call _init_clocks;
sp = usp; /* usp hasn't been touched, so restore from there */
#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 */
p1.l = _real_start;
p1.h = _real_start;
[p5 + (EVT15 - COREMMR_BASE)] = p1;
csync;
#ifdef CONFIG_EARLY_PRINTK
r0 = (EVT_IVG15 | EVT_IVHW | EVT_IRPTEN | EVT_EVX | EVT_NMI | EVT_RST | EVT_EMU) (z);
#else
r0 = EVT_IVG15 (z);
#endif
sti r0;
raise 15;
#ifdef CONFIG_EARLY_PRINTK
p0.l = _early_trap;
p0.h = _early_trap;
#else
p0.l = .LWAIT_HERE;
p0.h = .LWAIT_HERE;
#endif
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;
/* Pass the u-boot arguments to the global value command line */
R0 = R7;
call _cmdline_init;
sp += -12 + 4; /* +4 is for reti loading above */
call _init_pda
sp += 12;
jump.l _start_kernel;
ENDPROC(_real_start)
__FINIT
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