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[/] [openrisc/] [trunk/] [orpsocv2/] [sw/] [bootrom/] [bootrom.S] - Blame information for rev 403

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1 361 julius 
//////////////////////////////////////////////////////////////////////
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///                                                               ////
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/// bootrom                                                       ////
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///                                                               ////
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/// Assembly programs to be embedded inside system to aid boot    ////
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///                                                               ////
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/// Julius Baxter, julius@opencores.org                           ////
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///                                                               ////
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//////////////////////////////////////////////////////////////////////
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////                                                              ////
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//// Copyright (C) 2009, 2010 Authors and OPENCORES.ORG           ////
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////                                                              ////
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//// This source file may be used and distributed without         ////
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//// restriction provided that this copyright statement is not    ////
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//// removed from the file and that any derivative work contains  ////
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//// the original copyright notice and the associated disclaimer. ////
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////                                                              ////
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//// This source file is free software; you can redistribute it   ////
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//// and/or modify it under the terms of the GNU Lesser General   ////
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//// Public License as published by the Free Software Foundation; ////
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//// either version 2.1 of the License, or (at your option) any   ////
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//// later version.                                               ////
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////                                                              ////
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//// This source is distributed in the hope that it will be       ////
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//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
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//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
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//// PURPOSE.  See the GNU Lesser General Public License for more ////
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//// details.                                                     ////
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////                                                              ////
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//// You should have received a copy of the GNU Lesser General    ////
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//// Public License along with this source; if not, download it   ////
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//// from http://www.opencores.org/lgpl.shtml                     ////
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////                                                              ////
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//////////////////////////////////////////////////////////////////////
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// Defines for which bootrom app to use are in board.h - TODO: use the
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// processed orspoc-defines.v file for this define. It makes more sense
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// as this software ends up as gates.
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#include "board.h"
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42 403 julius 
#ifdef BOOTROM_SPI_FLASH
43 361 julius 
 
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        /* Assembly program to go into the boot ROM */
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        /* Currently just loads a program from SPI flash into RAM */
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        /* Assuming address at RAM_LOAD_BASE gets clobbered, we need
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           a byte writable address somewhere!*/
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#define SPI_BASE SPI0_BASE
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/* simple_spi driver */
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#define SPI_SPCR 0x0
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#define SPI_SPSR 0x1
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#define SPI_SPDR 0x2
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#define SPI_SPER 0x3
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#define SPI_SPSS 0x4
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#define SPI_SPCR_XFER_GO 0x51
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#define SPI_SPSS_INIT 0x1
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#define SPI_SPSR_RX_CHECK 0x01 /* Check bit 0 is cleared, fifo !empty*/
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#define RAM_LOAD_BASE SDRAM_BASE
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#define RESET_ADDR 0x100
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boot_init:
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        l.movhi r0, 0
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        l.movhi r1, RAM_LOAD_BASE
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        l.movhi r4, hi(SPI_BASE)
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spi_init:
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        l.ori r2, r0, SPI_SPCR_XFER_GO /* Setup SPCR with enable bit set */
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        l.sb SPI_SPCR(r4), r2
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        l.sb  SPI_SPSS(r4), r0         /* Clear SPI slave selects */
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        l.ori r6, r0, SPI_SPSS_INIT
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        l.sb  SPI_SPSS(r4), r6         /* Now put in appropriate slave select */
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        l.jal spi_xfer
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        l.ori r3, r0, 0x3              /* READ command opcode for SPI device */
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        l.jal spi_xfer
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        l.or r3, r0, r0
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        l.jal spi_xfer
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        l.or r3, r0, r0
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        l.jal spi_xfer
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        l.or r3, r0, r0
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        l.movhi r6, 0
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        l.movhi r7, 0xffff
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copy:
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        l.jal spi_xfer         /* Read a byte into r3 */
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        l.add r8, r1, r6       /* Calculate store address */
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        l.sb 0(r8), r3         /* Write byte to memory */
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        l.addi r6, r6, 1       /* Increment counter */
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        l.sfeqi r6, 0x4        /* Is this the first word */
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        l.bf store_sizeword    /* put sizeword in the register */
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        l.sfeq r6, r7          /* Check if we've finished loading the words */
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        l.bnf copy             /* Continue copying if not last word */
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        l.nop
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goto_reset:
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        l.ori r1, r1, RESET_ADDR
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        l.jr r1
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        l.sb  SPI_SPSS(r4), r0 /* Clear SPI slave selects */
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store_sizeword:
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        l.j copy
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        l.lwz r7, 0(r1)         /* Size word is in first word of SDRAM */
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spi_xfer:
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        l.sb SPI_SPDR(r4), r3  /* Dummy write what's in r3 */
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        l.ori r3, r0, SPI_SPSR_RX_CHECK /* r3 = , ensure loop just once */
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spi_xfer_poll:
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        l.andi r3, r3, SPI_SPSR_RX_CHECK /* AND read fifo bit empty */
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        l.sfeqi r3, SPI_SPSR_RX_CHECK    /* is bit set? ... */
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        l.bf spi_xfer_poll     /* ... if so, rxfifo empty, keep polling */
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        l.lbz r3, SPI_SPSR(r4) /* Read SPSR */
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        l.jr r9
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        l.lbz r3, SPI_SPDR(r4) /* Get data byte */
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#endif
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#ifdef BOOTROM_GOTO_RESET
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        /* Jump to reset vector in the SDRAM */
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        l.movhi r0, 0
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        l.movhi r4, SDRAM_BASE
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        l.ori r4, r4, 0x100
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        l.jr r4
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        l.nop
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#endif
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#ifdef BOOTROM_LOOP_AT_ZERO
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        /* Don't load app via SPI, instead just put an infinite loop into bottom
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        of memory and jump there.
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        */
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        l.movhi r0, 0
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        l.movhi r4, SDRAM_BASE
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        l.sw 0x0(r4), r0
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        l.movhi r5, hi(0x15000001) /* A l.nop 1 so sim exits if this enabled */
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        l.ori r5, r5, lo(0x15000001)
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        l.sw 0x4(r4), r5
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        l.sw 0x8(r4), r5
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        l.sw 0xc(r4), r5
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        l.jr r4
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        l.nop
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#endif
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#ifdef BOOTROM_LOOP_IN_ROM
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        /* Don't load app via SPI, instead just put an infinite loop into bottom
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        of memory and jump there.
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        */
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        l.movhi r0, 0
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        l.nop 0x1
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        l.j 0
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        l.nop
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        l.nop
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#endif

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