1 /*-
2  * Copyright (c) 2001 Benno Rice <benno@FreeBSD.org>
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  * 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  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: stable/12/stand/powerpc/kboot/ppc64_elf_freebsd.c 330864 2018-03-13 16:33:00Z imp $");
29 
30 #define __ELF_WORD_SIZE 64
31 
32 #include <sys/param.h>
33 #include <sys/endian.h>
34 #include <sys/linker.h>
35 
36 #include <machine/metadata.h>
37 #include <machine/elf.h>
38 
39 #include <stand.h>
40 
41 #include "bootstrap.h"
42 #include "host_syscall.h"
43 
44 extern char		end[];
45 extern void		*kerneltramp;
46 extern size_t		szkerneltramp;
47 
48 struct trampoline_data {
49 	uint32_t	kernel_entry;
50 	uint32_t	dtb;
51 	uint32_t	phys_mem_offset;
52 	uint32_t	of_entry;
53 	uint32_t	mdp;
54 	uint32_t	mdp_size;
55 };
56 
57 vm_offset_t md_load64(char *args, vm_offset_t *modulep, vm_offset_t *dtb);
58 
59 int
ppc64_elf_loadfile(char * filename,uint64_t dest,struct preloaded_file ** result)60 ppc64_elf_loadfile(char *filename, uint64_t dest,
61     struct preloaded_file **result)
62 {
63 	int	r;
64 
65 	r = __elfN(loadfile)(filename, dest, result);
66 	if (r != 0)
67 		return (r);
68 
69 	return (0);
70 }
71 
72 int
ppc64_elf_exec(struct preloaded_file * fp)73 ppc64_elf_exec(struct preloaded_file *fp)
74 {
75 	struct file_metadata	*fmp;
76 	vm_offset_t		mdp, dtb;
77 	Elf_Ehdr		*e;
78 	int			error;
79 	uint32_t		*trampoline;
80 	uint64_t		entry;
81 	uint64_t		trampolinebase;
82 	struct trampoline_data	*trampoline_data;
83 	int			nseg;
84 	void			*kseg;
85 
86 	if ((fmp = file_findmetadata(fp, MODINFOMD_ELFHDR)) == NULL) {
87 		return(EFTYPE);
88 	}
89 	e = (Elf_Ehdr *)&fmp->md_data;
90 
91 	/*
92 	 * Figure out where to put it.
93 	 *
94 	 * Linux does not allow to do kexec_load into
95 	 * any part of memory. Ask arch_loadaddr to
96 	 * resolve the first available chunk of physical
97 	 * memory where loading is possible (load_addr).
98 	 *
99 	 * Memory organization is shown below.
100 	 * It is assumed, that text segment offset of
101 	 * kernel ELF (KERNPHYSADDR) is non-zero,
102 	 * which is true for PPC/PPC64 architectures,
103 	 * where default is 0x100000.
104 	 *
105 	 * load_addr:                 trampoline code
106 	 * load_addr + KERNPHYSADDR:  kernel text segment
107 	 */
108 	trampolinebase = archsw.arch_loadaddr(LOAD_RAW, NULL, 0);
109 	printf("Load address at %#jx\n", (uintmax_t)trampolinebase);
110 	printf("Relocation offset is %#jx\n", (uintmax_t)elf64_relocation_offset);
111 
112 	/* Set up loader trampoline */
113 	trampoline = malloc(szkerneltramp);
114 	memcpy(trampoline, &kerneltramp, szkerneltramp);
115 
116 	/* Parse function descriptor for ELFv1 kernels */
117 	if ((e->e_flags & 3) == 2)
118 		entry = e->e_entry;
119 	else {
120 		archsw.arch_copyout(e->e_entry + elf64_relocation_offset,
121 		    &entry, 8);
122 		entry = be64toh(entry);
123 	}
124 
125 	/*
126 	 * Placeholder for trampoline data is at trampolinebase + 0x08
127 	 * CAUTION: all data must be Big Endian
128 	 */
129 	trampoline_data = (void*)&trampoline[2];
130 	trampoline_data->kernel_entry = htobe32(entry + elf64_relocation_offset);
131 	trampoline_data->phys_mem_offset = htobe32(0);
132 	trampoline_data->of_entry = htobe32(0);
133 
134 	if ((error = md_load64(fp->f_args, &mdp, &dtb)) != 0)
135 		return (error);
136 
137 	trampoline_data->dtb = htobe32(dtb);
138 	trampoline_data->mdp = htobe32(mdp);
139 	trampoline_data->mdp_size = htobe32(0xfb5d104d);
140 
141 	printf("Kernel entry at %#jx (%#x) ...\n",
142 	    entry, be32toh(trampoline_data->kernel_entry));
143 	printf("DTB at %#x, mdp at %#x\n",
144 	    be32toh(trampoline_data->dtb), be32toh(trampoline_data->mdp));
145 
146 	dev_cleanup();
147 
148 	archsw.arch_copyin(trampoline, trampolinebase, szkerneltramp);
149 	free(trampoline);
150 
151 	if (archsw.arch_kexec_kseg_get == NULL)
152 		panic("architecture did not provide kexec segment mapping");
153 	archsw.arch_kexec_kseg_get(&nseg, &kseg);
154 
155 	error = kexec_load(trampolinebase, nseg, (uintptr_t)kseg);
156 	if (error != 0)
157 		panic("kexec_load returned error: %d", error);
158 
159 	error = host_reboot(0xfee1dead, 672274793,
160 	    0x45584543 /* LINUX_REBOOT_CMD_KEXEC */, (uintptr_t)NULL);
161 	if (error != 0)
162 		panic("reboot returned error: %d", error);
163 
164 	while (1) {}
165 }
166 
167 struct file_format	ppc_elf64 =
168 {
169 	ppc64_elf_loadfile,
170 	ppc64_elf_exec
171 };
172