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Diffstat (limited to 'arch/blackfin/mach-common/head.S')
| -rw-r--r-- | arch/blackfin/mach-common/head.S | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/arch/blackfin/mach-common/head.S b/arch/blackfin/mach-common/head.S new file mode 100644 index 000000000000..191b4e974c4b --- /dev/null +++ b/arch/blackfin/mach-common/head.S @@ -0,0 +1,207 @@ +/* + * 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 |