xref: /titanic_41/usr/src/uts/i86pc/dboot/dboot_elfload.c (revision fcf3ce441efd61da9bb2884968af01cb7c1452cc)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 
28 #include <sys/types.h>
29 #include <sys/inttypes.h>
30 #include <sys/systm.h>
31 #include <sys/elf.h>
32 #include <sys/elf_notes.h>
33 
34 #include <util/memcpy.h>
35 
36 #include "dboot_xboot.h"
37 #include "dboot_elfload.h"
38 #include "dboot_printf.h"
39 
40 static caddr_t elf_file = 0;
41 
42 #define	PGETBYTES(offset)	((void *)(elf_file + (offset)))
43 
44 static void *
45 getehdr(void)
46 {
47 	uchar_t *ident;
48 	void *hdr = NULL;
49 
50 	ident = PGETBYTES(0);
51 	if (ident == NULL)
52 		dboot_panic("Cannot read kernel ELF header");
53 
54 	if (ident[EI_MAG0] != ELFMAG0 || ident[EI_MAG1] != ELFMAG1 ||
55 	    ident[EI_MAG2] != ELFMAG2 || ident[EI_MAG3] != ELFMAG3)
56 		dboot_panic("not an ELF file!");
57 
58 	if (ident[EI_CLASS] == ELFCLASS32)
59 		hdr = PGETBYTES(0);
60 	else if (ident[EI_CLASS] == ELFCLASS64)
61 		hdr = PGETBYTES(0);
62 	else
63 		dboot_panic("Unknown ELF class");
64 
65 	return (hdr);
66 }
67 
68 
69 /*
70  * parse the elf file for program information
71  */
72 int
73 dboot_elfload64(uintptr_t file_image)
74 {
75 	Elf64_Ehdr *eh;
76 	Elf64_Phdr *phdr;
77 	Elf64_Shdr *shdr;
78 	caddr_t allphdrs, sechdrs;
79 	int i;
80 	paddr_t src;
81 	paddr_t dst;
82 	paddr_t next_addr;
83 
84 	elf_file = (caddr_t)file_image;
85 
86 	allphdrs = NULL;
87 
88 	eh = getehdr();
89 	if (eh == NULL)
90 		dboot_panic("getehdr() failed");
91 
92 	if (eh->e_type != ET_EXEC)
93 		dboot_panic("not ET_EXEC, e_type = 0x%x", eh->e_type);
94 
95 	if (eh->e_phnum == 0 || eh->e_phoff == 0)
96 		dboot_panic("no program headers");
97 
98 	/*
99 	 * Get the program headers.
100 	 */
101 	allphdrs = PGETBYTES(eh->e_phoff);
102 	if (allphdrs == NULL)
103 		dboot_panic("Failed to get program headers e_phnum = %d",
104 		    eh->e_phnum);
105 
106 	/*
107 	 * Get the section headers.
108 	 */
109 	sechdrs = PGETBYTES(eh->e_shoff);
110 	if (sechdrs == NULL)
111 		dboot_panic("Failed to get section headers e_shnum = %d",
112 		    eh->e_shnum);
113 
114 	/*
115 	 * Next look for interesting program headers.
116 	 */
117 	for (i = 0; i < eh->e_phnum; i++) {
118 		/*LINTED [ELF program header alignment]*/
119 		phdr = (Elf64_Phdr *)(allphdrs + eh->e_phentsize * i);
120 
121 		/*
122 		 * Dynamically-linked executable.
123 		 * Complain.
124 		 */
125 		if (phdr->p_type == PT_INTERP) {
126 			dboot_printf("warning: PT_INTERP section\n");
127 			continue;
128 		}
129 
130 		/*
131 		 * at this point we only care about PT_LOAD segments
132 		 */
133 		if (phdr->p_type != PT_LOAD)
134 			continue;
135 
136 		if (phdr->p_flags == (PF_R | PF_W) && phdr->p_vaddr == 0) {
137 			dboot_printf("warning: krtld reloc info?\n");
138 			continue;
139 		}
140 
141 		/*
142 		 * If memory size is zero just ignore this header.
143 		 */
144 		if (phdr->p_memsz == 0)
145 			continue;
146 
147 		/*
148 		 * If load address 1:1 then ignore this header.
149 		 */
150 		if (phdr->p_paddr == phdr->p_vaddr) {
151 			if (prom_debug)
152 				dboot_printf("Skipping PT_LOAD segment for "
153 				    "paddr = 0x%lx\n", (ulong_t)phdr->p_paddr);
154 			continue;
155 		}
156 
157 		/*
158 		 * copy the data to kernel area
159 		 */
160 		if (phdr->p_paddr != FOUR_MEG && phdr->p_paddr != 2 * FOUR_MEG)
161 			dboot_panic("Bad paddr for kernel nucleus segment");
162 		src = (uintptr_t)PGETBYTES(phdr->p_offset);
163 		dst = ktext_phys + phdr->p_paddr - FOUR_MEG;
164 		if (prom_debug)
165 			dboot_printf("copying %ld bytes from ELF offset 0x%lx "
166 			    "to physaddr 0x%lx (va=0x%lx)\n",
167 			    (ulong_t)phdr->p_filesz, (ulong_t)phdr->p_offset,
168 			    (ulong_t)dst, (ulong_t)phdr->p_vaddr);
169 		(void) memcpy((void *)(uintptr_t)dst,
170 		    (void *)(uintptr_t)src, (size_t)phdr->p_filesz);
171 
172 		next_addr = dst + phdr->p_filesz;
173 	}
174 
175 
176 	/*
177 	 * Next look for bss
178 	 */
179 	for (i = 0; i < eh->e_shnum; i++) {
180 		shdr = (Elf64_Shdr *)(sechdrs + eh->e_shentsize * i);
181 
182 		/* zero out bss */
183 		if (shdr->sh_type == SHT_NOBITS) {
184 			(void) memset((void *)(uintptr_t)next_addr, 0,
185 			    shdr->sh_size);
186 			break;
187 		}
188 	}
189 
190 	/*
191 	 * Ignore the intepreter (or should we die if there is one??)
192 	 */
193 	return (0);
194 }
195