xref: /haiku/src/system/boot/loader/loader.cpp (revision cbe0a0c436162d78cc3f92a305b64918c839d079)
1 /*
2  * Copyright 2003-2009, Axel Dörfler, axeld@pinc-software.de.
3  * Distributed under the terms of the MIT License.
4  */
5 
6 
7 #include "loader.h"
8 #include "elf.h"
9 #include "RootFileSystem.h"
10 
11 #include <directories.h>
12 #include <OS.h>
13 #include <util/list.h>
14 #include <boot/stage2.h>
15 #include <boot/vfs.h>
16 #include <boot/platform.h>
17 #include <boot/stdio.h>
18 #include <boot/partitions.h>
19 
20 #include <unistd.h>
21 #include <string.h>
22 
23 
24 #ifndef BOOT_ARCH
25 #	error BOOT_ARCH has to be defined to differentiate the kernel per platform
26 #endif
27 
28 #define SYSTEM_DIRECTORY_PREFIX	"system/"
29 #define KERNEL_IMAGE	"kernel_" BOOT_ARCH
30 #define KERNEL_PATH		SYSTEM_DIRECTORY_PREFIX KERNEL_IMAGE
31 
32 #ifdef ALTERNATE_BOOT_ARCH
33 # define ALTERNATE_KERNEL_IMAGE	"kernel_" ALTERNATE_BOOT_ARCH
34 # define ALTERNATE_KERNEL_PATH	"system/" ALTERNATE_KERNEL_IMAGE
35 #endif
36 
37 
38 static const char* const kSystemDirectoryPrefix = SYSTEM_DIRECTORY_PREFIX;
39 
40 static const char *sKernelPaths[][2] = {
41 	{ KERNEL_PATH, KERNEL_IMAGE },
42 #ifdef ALTERNATE_BOOT_ARCH
43 	{ ALTERNATE_KERNEL_PATH, ALTERNATE_KERNEL_IMAGE },
44 #endif
45 	{ NULL, NULL },
46 };
47 
48 static const char *sAddonPaths[] = {
49 	kVolumeLocalSystemKernelAddonsDirectory,
50 	kVolumeLocalCommonNonpackagedKernelAddonsDirectory,
51 	kVolumeLocalCommonKernelAddonsDirectory,
52 	kVolumeLocalUserNonpackagedKernelAddonsDirectory,
53 	kVolumeLocalUserKernelAddonsDirectory,
54 	NULL
55 };
56 
57 
58 int
59 open_maybe_packaged(BootVolume& volume, const char* path, int openMode)
60 {
61 	if (strncmp(path, kSystemDirectoryPrefix, strlen(kSystemDirectoryPrefix))
62 			== 0) {
63 		path += strlen(kSystemDirectoryPrefix);
64 		return open_from(volume.SystemDirectory(), path, openMode);
65 	}
66 
67 	return open_from(volume.RootDirectory(), path, openMode);
68 }
69 
70 
71 static int
72 find_kernel(BootVolume& volume, const char** name = NULL)
73 {
74 	for (int32 i = 0; sKernelPaths[i][0] != NULL; i++) {
75 		int fd = open_maybe_packaged(volume, sKernelPaths[i][0], O_RDONLY);
76 		if (fd >= 0) {
77 			if (name)
78 				*name = sKernelPaths[i][1];
79 
80 			return fd;
81 		}
82 	}
83 
84 	return B_ENTRY_NOT_FOUND;
85 }
86 
87 
88 bool
89 is_bootable(Directory *volume)
90 {
91 	if (volume->IsEmpty())
92 		return false;
93 
94 	BootVolume bootVolume;
95 	if (bootVolume.SetTo(volume) != B_OK)
96 		return false;
97 
98 	// check for the existance of a kernel (for our platform)
99 	int fd = find_kernel(bootVolume);
100 	if (fd < 0)
101 		return false;
102 
103 	close(fd);
104 
105 	return true;
106 }
107 
108 
109 status_t
110 load_kernel(stage2_args* args, BootVolume& volume)
111 {
112 	const char *name;
113 	int fd = find_kernel(volume, &name);
114 	if (fd < B_OK)
115 		return fd;
116 
117 	dprintf("load kernel %s...\n", name);
118 
119 	elf_init();
120 	preloaded_image *image;
121 	status_t status = elf_load_image(fd, &image);
122 
123 	close(fd);
124 
125 	if (status < B_OK) {
126 		dprintf("loading kernel failed: %" B_PRIx32 "!\n", status);
127 		return status;
128 	}
129 
130 	gKernelArgs.kernel_image = image;
131 
132 	status = elf_relocate_image(gKernelArgs.kernel_image);
133 	if (status < B_OK) {
134 		dprintf("relocating kernel failed: %" B_PRIx32 "!\n", status);
135 		return status;
136 	}
137 
138 	gKernelArgs.kernel_image->name = kernel_args_strdup(name);
139 
140 	return B_OK;
141 }
142 
143 
144 static status_t
145 load_modules_from(BootVolume& volume, const char* path)
146 {
147 	// we don't have readdir() & co. (yet?)...
148 
149 	int fd = open_maybe_packaged(volume, path, O_RDONLY);
150 	if (fd < B_OK)
151 		return fd;
152 
153 	Directory *modules = (Directory *)get_node_from(fd);
154 	if (modules == NULL)
155 		return B_ENTRY_NOT_FOUND;
156 
157 	void *cookie;
158 	if (modules->Open(&cookie, O_RDONLY) == B_OK) {
159 		char name[B_FILE_NAME_LENGTH];
160 		while (modules->GetNextEntry(cookie, name, sizeof(name)) == B_OK) {
161 			if (!strcmp(name, ".") || !strcmp(name, ".."))
162 				continue;
163 
164 			status_t status = elf_load_image(modules, name);
165 			if (status != B_OK)
166 				dprintf("Could not load \"%s\" error %" B_PRIx32 "\n", name, status);
167 		}
168 
169 		modules->Close(cookie);
170 	}
171 
172 	return B_OK;
173 }
174 
175 
176 status_t
177 load_modules(stage2_args* args, BootVolume& volume)
178 {
179 	int32 failed = 0;
180 
181 	// ToDo: this should be mostly replaced by a hardware oriented detection mechanism
182 
183 	int32 i = 0;
184 	for (; sAddonPaths[i]; i++) {
185 		char path[B_FILE_NAME_LENGTH];
186 		snprintf(path, sizeof(path), "%s/boot", sAddonPaths[i]);
187 
188 		if (load_modules_from(volume, path) != B_OK)
189 			failed++;
190 	}
191 
192 	if (failed == i) {
193 		// couldn't load any boot modules
194 		// fall back to load all modules (currently needed by the boot floppy)
195 		const char *paths[] = { "bus_managers", "busses/ide", "busses/scsi",
196 			"generic", "partitioning_systems", "drivers/bin", NULL};
197 
198 		for (int32 i = 0; paths[i]; i++) {
199 			char path[B_FILE_NAME_LENGTH];
200 			snprintf(path, sizeof(path), "%s/%s", sAddonPaths[0], paths[i]);
201 			load_modules_from(volume, path);
202 		}
203 	}
204 
205 	// and now load all partitioning and file system modules
206 	char path[B_FILE_NAME_LENGTH];
207 	snprintf(path, sizeof(path), "%s/%s", sAddonPaths[0], "file_systems");
208 	load_modules_from(volume, path);
209 	snprintf(path, sizeof(path), "%s/%s", sAddonPaths[0], "partitioning_systems");
210 	load_modules_from(volume, path);
211 
212 	return B_OK;
213 }
214