diff options
Diffstat (limited to 'nuttx/arch/dm320/src/up_restart.S')
-rw-r--r-- | nuttx/arch/dm320/src/up_restart.S | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/nuttx/arch/dm320/src/up_restart.S b/nuttx/arch/dm320/src/up_restart.S new file mode 100644 index 000000000..ed1ecde5b --- /dev/null +++ b/nuttx/arch/dm320/src/up_restart.S @@ -0,0 +1,136 @@ +/******************************************************************** + * up_head.S + * + * Copyright (C) 2007 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name Gregory Nutt nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ********************************************************************/ + +/******************************************************************** + * Included Files + ********************************************************************/ + +#include <nuttx/config.h> +#include "up_internal.h" +#include "dm320.h" + +/******************************************************************** + * Definitions + ********************************************************************/ + +/******************************************************************** + * Assembly Macros + ********************************************************************/ + +/* Since the page table is closely related to the NuttX base + * address, we can convert the page table base address to the + * base address of the section containing both. + */ + + .macro mksection, section, pgtable + bic \section, \pgtable, #0x000ff000 + .endm + +/************************************************************************** + * Name: up_restart + **************************************************************************/ + + .text + .globl up_restart + .type up_restart, %function +up_restart: + /* Make sure that we are in SVC mode with all IRQs disabled */ + + mov r0, #(SVC_MODE | PSR_I_BIT | PSR_F_BIT) + msr cpsr_c, r0 + + /* Create identity mapping for first MB section to support + * this re-start logic executing out of the physical address + * space. + */ + + mksection r0, r4 /* r0=phys. base section */ + ldr r1, .LCmmuflags /* FLGS=MMU_MEMFLAGS */ + add r3, r1, r0 /* r3=flags + base */ + str r3, [r4, r0, lsr #18] /* identity mapping */ + + /* Jump into the physical address space */ + + ldr pc, .LCphysrestart + nop + nop + + /* We are now executing at our physical address, with the + * MMU disabled. + */ + +up_phyrestart: + + mov r0, #0 + mcr p15, 0, r0, c7, c7 /* Invalidate I,D caches */ + mcr p15, 0, r0, c7, c10, 4 /* Drain write buffer */ + mcr p15, 0, r0, c8, c7 /* Invalidate I,D TLBs */ + + /* Clear bits in control register (see start.h): Disable, + * MMU, Data cache, alignment traps, write buffer, Instruction + * cache, exceptions at 0xffff0000, round robin) + */ + + mrc p15, 0, r0, c1, c0 /* Get control register */ + bic r0, r0, #(CR_M|CR_C|CR_A|CR_W) + bic r0, r0, #(CR_S|CR_I|CR_V|CR_RR) + mcr p15, 0, r0, c1, c0, 0 /* Write control reg */ + + /* We know that the the bootloader entry point is at the + * beginning of flash. + */ +#if 1 + ldr pc, .LCbtldrentry /* Restart bootloader */ +#else + b __start /* Restart Nuttx */ +#endif + + .type .LCphysrestart, %object +.LCphysrestart: + .long (up_phyrestart - DM320_SDRAM_VADDR + DM320_SDRAM_PADDR) +.LCbtldrentry: + .long DM320_EXT_MEM_PADDR + +/************************************************************************** + * PC_Relative Data + **************************************************************************/ + + .type .LCmmuflags, %object +.LCmmuflags: + .long MMU_MEMFLAGS + .size up_restart, .-up_restart + + .end + |