/* * barebox - start.S Startup file of barebox 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 , * Kenneth Albanowski , * 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. * */ #include #include #include #include #include .section ".text_entry","ax" .macro checker p0.h = FIO0_DIR >> 16; p0.l = FIO0_DIR & 0xFFFF; r0 = (1 << 9); w[p0] = r0; p0.h = FIO0_FLAG_S >> 16; p0.l = FIO0_FLAG_S & 0xFFFF; r0 = (1 << 9); w[p0] = r0; 1: jump 1b .endm _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 = hi(EVT_EMULATION_ADDR) p0.l = lo(EVT_EMULATION_ADDR); 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 = lo(0xffb01000); sp.h = hi(0xffb01000); /* 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 = lo(TEXT_BASE); p2.h = hi(TEXT_BASE); p3 = 0x04; p4.l = ___bss_start; p4.h = ___bss_start; loop1: r1 = [p1 ++ p3]; [p2 ++ p3] = r1; cc=p2==p4; if !cc jump loop1; /* * configure STACK */ r0.h = hi(STACK_BASE); r0.l = lo(STACK_BASE); 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 = lo(EVT_IVG15_ADDR); p0.h = hi(EVT_IVG15_ADDR); p1.l = _real_start; p1.h = _real_start; [p0] = p1; p0.l = lo(IMASK); p0.h = hi(IMASK); 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; #if defined(CONFIG_EZKIT533) || defined(CONFIG_EZKIT561) p0.l = lo(WDOG_CTL); p0.h = hi(WDOG_CTL); r0 = WATCHDOG_DISABLE(z); w[p0] = r0; #endif #ifdef CONFIG_BF537 /* Initialise General-Purpose I/O Modules on BF537 * Rev 0.0 Anomaly 05000212 - PORTx_FER, * PORT_MUX Registers Do Not accept "writes" correctly */ p0.h = hi(PORTF_FER); p0.l = lo(PORTF_FER); R0.L = W[P0]; /* Read */ nop; nop; nop; ssync; R0 = 0x000F(Z); W[P0] = R0.L; /* Write */ nop; nop; nop; ssync; W[P0] = R0.L; /* Enable peripheral function of PORTF for UART0 and UART1 */ nop; nop; nop; ssync; p0.h = hi(PORTH_FER); p0.l = lo(PORTH_FER); R0.L = W[P0]; /* Read */ nop; nop; nop; ssync; R0 = 0xFFFF(Z); W[P0] = R0.L; /* Write */ nop; nop; nop; ssync; W[P0] = R0.L; /* Enable peripheral function of PORTH for MAC */ nop; nop; nop; ssync; #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: #if defined(CONFIG_BF537)&&defined(CONFIG_POST) p0.l = post_flag; p0.h = post_flag; r0 = r7; [p0] = r0; #endif p0.l = _start_barebox; p0.h = _start_barebox; jump (p0); reset_start: p0.h = hi(WDOG_CNT); p0.l = lo(WDOG_CNT); r0 = 0x0010; w[p0] = r0; p0.h = hi(WDOG_CTL); p0.l = lo(WDOG_CTL); r0 = 0x0000; w[p0] = r0; reset_wait: jump reset_wait; reset_end: nop; _exit: jump.s _exit; get_pc: r0 = rets; rts;