source: mainline/boot/arch/arm32/src/main.c@ c77cfd8

ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since c77cfd8 was cfdeedc, checked in by Jiří Zárevúcky <zarevucky.jiri@…>, 7 years ago

Keep kernel in ELF format

By keeping kernel in an ELF file (instead of converting it to
a flat binary), we can use the information it contains, like
symbol table and debug info.

We can also later implement more advanced functionality, like
loading kernel at multiple discontiguous blocks, or loading
a position-independent kernel at a randomized address.

Currently the functionality is quite restricted, to keep changes
to a minimum. Code in boot/generic/src/kernel.c validates that
the kernel image was built with the same addresses as the boot
loader uses, giving an extra level of sanity checking compared
to a flat binary.

  • Property mode set to 100644
File size: 3.4 KB
Line 
1/*
2 * Copyright (c) 2007 Michal Kebrt
3 * All rights reserved.
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 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup boot_arm32
30 * @{
31 */
32/** @file
33 * @brief Bootstrap.
34 */
35
36#include <arch/main.h>
37#include <arch/types.h>
38#include <arch/asm.h>
39#include <arch/mm.h>
40#include <halt.h>
41#include <printf.h>
42#include <memstr.h>
43#include <version.h>
44#include <macros.h>
45#include <align.h>
46#include <stdbool.h>
47#include <str.h>
48#include <errno.h>
49#include <inflate.h>
50#include <arch/cp15.h>
51#include <payload.h>
52#include <kernel.h>
53
54static void clean_dcache_poc(void *address, size_t size)
55{
56 const uintptr_t addr = (uintptr_t) address;
57
58#if !defined(PROCESSOR_ARCH_armv7_a)
59 bool sep;
60 if (MIDR_read() != CTR_read()) {
61 sep = (CTR_read() & CTR_SEP_FLAG) == CTR_SEP_FLAG;
62 } else {
63 printf("Unknown cache type.\n");
64 halt();
65 }
66#endif
67
68 for (uintptr_t a = ALIGN_DOWN(addr, CP15_C7_MVA_ALIGN); a < addr + size;
69 a += CP15_C7_MVA_ALIGN) {
70#if defined(PROCESSOR_ARCH_armv7_a)
71 DCCMVAC_write(a);
72#else
73 if (sep)
74 DCCMVA_write(a);
75 else
76 CCMVA_write(a);
77#endif
78 }
79}
80
81static bootinfo_t bootinfo;
82
83void bootstrap(void)
84{
85 /* Enable MMU and caches */
86 mmu_start();
87 version_print();
88
89 printf("Boot loader: %p -> %p\n", loader_start, loader_end);
90 printf("\nMemory statistics\n");
91 printf(" %p|%p: bootstrap stack\n", &boot_stack, &boot_stack);
92 printf(" %p|%p: bootstrap page table\n", &boot_pt, &boot_pt);
93 printf(" %p|%p: boot info structure\n", &bootinfo, &bootinfo);
94 printf(" %p|%p: kernel entry point\n",
95 (void *) PA2KA(BOOT_OFFSET), (void *) BOOT_OFFSET);
96
97 // FIXME: Use the correct value.
98 uint8_t *kernel_dest = (uint8_t *) BOOT_OFFSET;
99 uint8_t *ram_end = kernel_dest + (1 << 24);
100
101 extract_payload(&bootinfo.taskmap, kernel_dest, ram_end,
102 PA2KA(kernel_dest), clean_dcache_poc);
103
104 /* Flush PT too. We need this if we disable caches later */
105 clean_dcache_poc(boot_pt, PTL0_ENTRIES * PTL0_ENTRY_SIZE);
106
107 uintptr_t entry = check_kernel((void *) PA2KA(BOOT_OFFSET));
108
109 printf("Booting the kernel...\n");
110 jump_to_kernel((void *) entry, &bootinfo);
111}
112
113/** @}
114 */
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