payloads/libpayload/arch/arm64/main.c

   1 /*
   2  *
   3  * Copyright (C) 2008 Advanced Micro Devices, Inc.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <exception.h>
  30 #include <libpayload.h>
  31 #include <arch/mmu.h>
  32
  33 /*
  34  * Func: pre_sysinfo_scan_mmu_setup
  35  * Desc: We need to setup and enable MMU before we can go to scan coreboot
  36  * tables. However, we are not sure what all memory regions to map. Thus,
  37  * initializing minimum required memory ranges
  38  */
  39 static void pre_sysinfo_scan_mmu_setup(void)
  40 {
  41         uint64_t start = (uint64_t)&_start;
  42         uint64_t end = (uint64_t)&_end;
  43
  44         /* Memory range 1: Covers the area occupied by payload */
  45         mmu_presysinfo_memory_used(start, end - start);
  46
  47         /*
  48          * Memory range 2: coreboot tables
  49          *
  50          * Maximum size is assumed 2 pages in case it crosses the GRANULE_SIZE
  51          * boundary
  52          */
  53         mmu_presysinfo_memory_used((uint64_t)get_cb_header_ptr(),
  54                                    2 * GRANULE_SIZE);
  55
  56         mmu_presysinfo_enable();
  57 }
  58
  59 /*
  60  * Func: post_sysinfo_scan_mmu_setup
  61  * Desc: Once we have scanned coreboot tables, we have complete information
  62  * about different memory ranges. Thus, we can perform a complete mmu
  63  * initialization. Also, this takes care of DMA area setup
  64  */
  65 static void post_sysinfo_scan_mmu_setup(void)
  66 {
  67         struct memrange *ranges;
  68         uint64_t nranges;
  69         struct mmu_ranges mmu_ranges;
  70         struct mmu_memrange *dma_range;
  71
  72         /* Get memrange info from lib_sysinfo */
  73         lib_sysinfo_get_memranges(&ranges, &nranges);
  74
  75         /* Get memory ranges for mmu init from lib_sysinfo memrange */
  76         dma_range = mmu_init_ranges_from_sysinfo(ranges, nranges, &mmu_ranges);
  77
  78         /* Disable mmu */
  79         mmu_disable();
  80
  81         /* Init mmu */
  82         mmu_init(&mmu_ranges);
  83
  84         /* Enable mmu */
  85         mmu_enable();
  86
  87         /* Init dma memory */
  88         init_dma_memory((void *)dma_range->base, dma_range->size);
  89 }
  90
  91 /**
  92  * This is our C entry function - set up the system
  93  * and jump into the payload entry point.
  94  */
  95 void start_main(void);
  96 void start_main(void)
  97 {
  98         extern int main(int argc, char **argv);
  99
 100         pre_sysinfo_scan_mmu_setup();
 101
 102         /* Gather system information. */
 103         lib_get_sysinfo();
 104
 105         post_sysinfo_scan_mmu_setup();
 106
 107 #if !CONFIG(LP_SKIP_CONSOLE_INIT)
 108         console_init();
 109 #endif
 110
 111         exception_init();
 112
 113         /*
 114          * Any other system init that has to happen before the
 115          * user gets control goes here.
 116          */
 117
 118         /*
 119          * Go to the entry point.
 120          * In the future we may care about the return value.
 121          */
 122
 123         (void) main(0, NULL);
 124
 125         /*
 126          * Returning here will go to the _leave function to return
 127          * us to the original context.
 128          */
 129 }