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+/*
+ * U-boot - start.S Startup file of u-boot for BF533/BF561
+ *
+ * Copyright (c) 2005 blackfin.uclinux.org
+ *
+ * This file is based on head.S
+ * Copyright (c) 2003 Metrowerks/Motorola
+ * Copyright (C) 1998 D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>,
+ * Kenneth Albanowski <kjahds@kjahds.com>,
+ * The Silver Hammer Group, Ltd.
+ * (c) 1995, Dionne & Associates
+ * (c) 1995, DKG Display Tech.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * Note: A change in this file subsequently requires a change in
+ * board/$(board_name)/config.mk for a valid u-boot.bin
+ */
+
+#define ASSEMBLY
+
+#include <linux/config.h>
+#include <config.h>
+#include <asm/blackfin.h>
+
+.global _stext;
+.global __bss_start;
+.global start;
+.global _start;
+.global _rambase;
+.global _ramstart;
+.global _ramend;
+.global edata;
+.global _initialize;
+.global _exit;
+.global flashdataend;
+.global init_sdram;
+
+.text
+_start:
+start:
+_stext:
+
+ R0 = 0x32;
+ SYSCFG = R0;
+ SSYNC;
+
+ /*
+ * As per HW reference manual DAG registers,
+ * DATA and Address resgister shall be zero'd
+ * in initialization, after a reset state
+ */
+ r1 = 0; /* Data registers zero'd */
+ r2 = 0;
+ r3 = 0;
+ r4 = 0;
+ r5 = 0;
+ r6 = 0;
+ r7 = 0;
+
+ p0 = 0; /* Address registers zero'd */
+ p1 = 0;
+ p2 = 0;
+ p3 = 0;
+ p4 = 0;
+ p5 = 0;
+
+ i0 = 0; /* DAG Registers zero'd */
+ i1 = 0;
+ i2 = 0;
+ i3 = 0;
+ m0 = 0;
+ m1 = 0;
+ m3 = 0;
+ m3 = 0;
+ l0 = 0;
+ l1 = 0;
+ l2 = 0;
+ l3 = 0;
+ b0 = 0;
+ b1 = 0;
+ b2 = 0;
+ b3 = 0;
+
+ /*
+ * Set loop counters to zero, to make sure that
+ * hw loops are disabled.
+ */
+ r0 = 0;
+ lc0 = r0;
+ lc1 = r0;
+
+ SSYNC;
+
+ /* Check soft reset status */
+ p0.h = SWRST >> 16;
+ p0.l = SWRST & 0xFFFF;
+ r0.l = w[p0];
+
+ cc = bittst(r0, 15);
+ if !cc jump no_soft_reset;
+
+ /* Clear Soft reset */
+ r0 = 0x0000;
+ w[p0] = r0;
+ ssync;
+
+no_soft_reset:
+ nop;
+
+ /* Clear EVT registers */
+ p0.h = (EVT_EMULATION_ADDR >> 16);
+ p0.l = (EVT_EMULATION_ADDR & 0xFFFF);
+ p0 += 8;
+ p1 = 14;
+ r1 = 0;
+ LSETUP(4,4) lc0 = p1;
+ [ p0 ++ ] = r1;
+
+ p0.h = hi(SIC_IWR);
+ p0.l = lo(SIC_IWR);
+ r0.l = 0x1;
+ w[p0] = r0.l;
+ SSYNC;
+
+ sp.l = (0xffb01000 & 0xFFFF);
+ sp.h = (0xffb01000 >> 16);
+
+ /*
+ * Check if the code is in SDRAM
+ * If the code is in SDRAM, skip SDRAM initializaiton
+ */
+ call get_pc;
+ r3.l = 0x0;
+ r3.h = 0x2000;
+ cc = r0 < r3 (iu);
+ if cc jump sdram_initialized;
+ call init_sdram;
+ /* relocate into to RAM */
+sdram_initialized:
+ call get_pc;
+offset:
+ r2.l = offset;
+ r2.h = offset;
+ r3.l = start;
+ r3.h = start;
+ r1 = r2 - r3;
+
+ r0 = r0 - r1;
+ p1 = r0;
+
+ p2.l = (CFG_MONITOR_BASE & 0xffff);
+ p2.h = (CFG_MONITOR_BASE >> 16);
+
+ p3 = 0x04;
+ p4.l = ((CFG_MONITOR_BASE + CFG_MONITOR_LEN) & 0xffff);
+ p4.h = ((CFG_MONITOR_BASE + CFG_MONITOR_LEN) >> 16);
+loop1:
+ r1 = [p1 ++ p3];
+ [p2 ++ p3] = r1;
+ cc=p2==p4;
+ if !cc jump loop1;
+ /*
+ * configure STACK
+ */
+ r0.h = (CONFIG_STACKBASE >> 16);
+ r0.l = (CONFIG_STACKBASE & 0xFFFF);
+ sp = r0;
+ fp = sp;
+
+ /*
+ * This next 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.
+ */
+
+ /* To keep ourselves in the supervisor mode */
+ p0.l = (EVT_IVG15_ADDR & 0xFFFF);
+ p0.h = (EVT_IVG15_ADDR >> 16);
+
+ p1.l = _real_start;
+ p1.h = _real_start;
+ [p0] = p1;
+
+ p0.l = (IMASK & 0xFFFF);
+ p0.h = (IMASK >> 16);
+ r0.l = LO(IVG15_POS);
+ r0.h = HI(IVG15_POS);
+ [p0] = r0;
+ raise 15;
+ p0.l = WAIT_HERE;
+ p0.h = WAIT_HERE;
+ reti = p0;
+ rti;
+
+WAIT_HERE:
+ jump WAIT_HERE;
+
+.global _real_start;
+_real_start:
+ [ -- sp ] = reti;
+
+#ifdef CONFIG_EZKIT561
+ p0.l = (WDOG_CTL & 0xFFFF);
+ p0.h = (WDOG_CTL >> 16);
+ r0 = WATCHDOG_DISABLE(z);
+ w[p0] = r0;
+#endif
+
+ /* DMA reset code to Hi of L1 SRAM */
+copy:
+ P1.H = hi(SYSMMR_BASE); /* P1 Points to the beginning of SYSTEM MMR Space */
+ P1.L = lo(SYSMMR_BASE);
+
+ R0.H = reset_start; /* Source Address (high) */
+ R0.L = reset_start; /* Source Address (low) */
+ R1.H = reset_end;
+ R1.L = reset_end;
+ R2 = R1 - R0; /* Count */
+ R1.H = hi(L1_ISRAM); /* Destination Address (high) */
+ R1.L = lo(L1_ISRAM); /* Destination Address (low) */
+ R3.L = DMAEN; /* Source DMAConfig Value (8-bit words) */
+ R4.L = (DI_EN | WNR | DMAEN); /* Destination DMAConfig Value (8-bit words) */
+
+DMA:
+ R6 = 0x1 (Z);
+ W[P1+OFFSET_(MDMA_S0_X_MODIFY)] = R6; /* Source Modify = 1 */
+ W[P1+OFFSET_(MDMA_D0_X_MODIFY)] = R6; /* Destination Modify = 1 */
+
+ [P1+OFFSET_(MDMA_S0_START_ADDR)] = R0; /* Set Source Base Address */
+ W[P1+OFFSET_(MDMA_S0_X_COUNT)] = R2; /* Set Source Count */
+ /* Set Source DMAConfig = DMA Enable,
+ Memory Read, 8-Bit Transfers, 1-D DMA, Flow - Stop */
+ W[P1+OFFSET_(MDMA_S0_CONFIG)] = R3;
+
+ [P1+OFFSET_(MDMA_D0_START_ADDR)] = R1; /* Set Destination Base Address */
+ W[P1+OFFSET_(MDMA_D0_X_COUNT)] = R2; /* Set Destination Count */
+ /* Set Destination DMAConfig = DMA Enable,
+ Memory Write, 8-Bit Transfers, 1-D DMA, Flow - Stop, IOC */
+ W[P1+OFFSET_(MDMA_D0_CONFIG)] = R4;
+
+WAIT_DMA_DONE:
+ p0.h = hi(MDMA_D0_IRQ_STATUS);
+ p0.l = lo(MDMA_D0_IRQ_STATUS);
+ R0 = W[P0](Z);
+ CC = BITTST(R0, 0);
+ if ! CC jump WAIT_DMA_DONE
+
+ R0 = 0x1;
+ W[P1+OFFSET_(MDMA_D0_IRQ_STATUS)] = R0; /* Write 1 to clear DMA interrupt */
+
+ /* Initialize BSS Section with 0 s */
+ p1.l = __bss_start;
+ p1.h = __bss_start;
+ p2.l = _end;
+ p2.h = _end;
+ r1 = p1;
+ r2 = p2;
+ r3 = r2 - r1;
+ r3 = r3 >> 2;
+ p3 = r3;
+ lsetup (_clear_bss, _clear_bss_end ) lc1 = p3;
+ CC = p2<=p1;
+ if CC jump _clear_bss_skip;
+ r0 = 0;
+_clear_bss:
+_clear_bss_end:
+ [p1++] = r0;
+_clear_bss_skip:
+
+ p0.l = _start1;
+ p0.h = _start1;
+ jump (p0);
+
+reset_start:
+ p0.h = WDOG_CNT >> 16;
+ p0.l = WDOG_CNT & 0xffff;
+ r0 = 0x0010;
+ w[p0] = r0;
+ p0.h = WDOG_CTL >> 16;
+ p0.l = WDOG_CTL & 0xffff;
+ r0 = 0x0000;
+ w[p0] = r0;
+reset_wait:
+ jump reset_wait;
+
+reset_end: nop;
+
+_exit:
+ jump.s _exit;
+get_pc:
+ r0 = rets;
+ rts;
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