xref: /freebsd/sys/powerpc/ofw/ofw_initrd.c (revision e9ac41698b2f322d55ccf9da50a3596edb2c1800)
1 /*-
2  * Copyright (C) 2018 Breno Leitao
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
17  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
18  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
19  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
20  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
21  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
22  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23  */
24 
25 #include <sys/param.h>
26 #include <sys/kernel.h>
27 #include <sys/systm.h>
28 #include <sys/module.h>
29 #include <sys/types.h>
30 #include <sys/proc.h>
31 
32 #include <vm/vm.h>
33 #include <vm/pmap.h>
34 
35 #include <machine/bus.h>
36 #include <machine/elf.h>
37 #include <machine/param.h>
38 
39 #include <dev/ofw/openfirm.h>
40 #include <dev/ofw/ofw_bus.h>
41 #include <dev/ofw/ofw_bus_subr.h>
42 
43 #include "opt_md.h"
44 
45 extern u_char *mfs_root;
46 extern int mfs_root_size;
47 
48 static void ofw_initrd_probe_and_attach(void *junk);
49 
50 SYSINIT(ofw_initrd_probe_and_attach, SI_SUB_KMEM, SI_ORDER_ANY,
51     ofw_initrd_probe_and_attach, NULL);
52 
53 static void
54 ofw_initrd_probe_and_attach(void *junk)
55 {
56 	phandle_t chosen;
57 	vm_paddr_t start, end;
58 	pcell_t cell[2];
59 	ssize_t size;
60 	u_char *taste;
61 	Elf_Ehdr ehdr;
62 
63 	if (!hw_direct_map)
64 		return;
65 
66 	chosen = OF_finddevice("/chosen");
67 	if (chosen <= 0)
68 		return;
69 
70 	if (!OF_hasprop(chosen, "linux,initrd-start") ||
71 	    !OF_hasprop(chosen, "linux,initrd-end"))
72 		return;
73 
74 	size = OF_getencprop(chosen, "linux,initrd-start", cell, sizeof(cell));
75 	if (size == 4)
76 		start = cell[0];
77 	else if (size == 8)
78 		start = (uint64_t)cell[0] << 32 | cell[1];
79 	else {
80 		printf("ofw_initrd: Wrong linux,initrd-start size\n");
81 		return;
82 	}
83 
84 	size = OF_getencprop(chosen, "linux,initrd-end", cell, sizeof(cell));
85 	if (size == 4)
86 		end = cell[0];
87 	else if (size == 8)
88 		end = (uint64_t)cell[0] << 32 | cell[1];
89 	else{
90 		printf("ofw_initrd: Wrong linux,initrd-end size\n");
91 		return;
92 	}
93 
94 	if (end - start > 0) {
95 		taste = (u_char*) PHYS_TO_DMAP(start);
96 		memcpy(&ehdr, taste, sizeof(ehdr));
97 
98 		if (IS_ELF(ehdr)) {
99 			printf("ofw_initrd: initrd is kernel image!\n");
100 			return;
101 		}
102 
103 		mfs_root = taste;
104 		mfs_root_size = end - start;
105 		printf("ofw_initrd: initrd loaded at 0x%08lx-0x%08lx\n",
106 			start, end);
107 	}
108 }
109