xref: /openbmc/linux/arch/powerpc/boot/simpleboot.c (revision d2912cb1)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * The simple platform -- for booting when firmware doesn't supply a device
4  *                        tree or any platform configuration information.
5  *                        All data is extracted from an embedded device tree
6  *                        blob.
7  *
8  * Authors: Scott Wood <scottwood@freescale.com>
9  *          Grant Likely <grant.likely@secretlab.ca>
10  *
11  * Copyright (c) 2007 Freescale Semiconductor, Inc.
12  * Copyright (c) 2008 Secret Lab Technologies Ltd.
13  */
14 
15 #include "ops.h"
16 #include "types.h"
17 #include "io.h"
18 #include "stdio.h"
19 #include <libfdt.h>
20 
21 BSS_STACK(4*1024);
22 
23 extern int platform_specific_init(void) __attribute__((weak));
24 
platform_init(unsigned long r3,unsigned long r4,unsigned long r5,unsigned long r6,unsigned long r7)25 void platform_init(unsigned long r3, unsigned long r4, unsigned long r5,
26 		   unsigned long r6, unsigned long r7)
27 {
28 	const u32 *na, *ns, *reg, *timebase;
29 	u64 memsize64;
30 	int node, size, i;
31 
32 	/* Make sure FDT blob is sane */
33 	if (fdt_check_header(_dtb_start) != 0)
34 		fatal("Invalid device tree blob\n");
35 
36 	/* Find the #address-cells and #size-cells properties */
37 	node = fdt_path_offset(_dtb_start, "/");
38 	if (node < 0)
39 		fatal("Cannot find root node\n");
40 	na = fdt_getprop(_dtb_start, node, "#address-cells", &size);
41 	if (!na || (size != 4))
42 		fatal("Cannot find #address-cells property");
43 	ns = fdt_getprop(_dtb_start, node, "#size-cells", &size);
44 	if (!ns || (size != 4))
45 		fatal("Cannot find #size-cells property");
46 
47 	/* Find the memory range */
48 	node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type",
49 					     "memory", sizeof("memory"));
50 	if (node < 0)
51 		fatal("Cannot find memory node\n");
52 	reg = fdt_getprop(_dtb_start, node, "reg", &size);
53 	if (size < (*na+*ns) * sizeof(u32))
54 		fatal("cannot get memory range\n");
55 
56 	/* Only interested in memory based at 0 */
57 	for (i = 0; i < *na; i++)
58 		if (*reg++ != 0)
59 			fatal("Memory range is not based at address 0\n");
60 
61 	/* get the memsize and truncate it to under 4G on 32 bit machines */
62 	memsize64 = 0;
63 	for (i = 0; i < *ns; i++)
64 		memsize64 = (memsize64 << 32) | *reg++;
65 	if (sizeof(void *) == 4 && memsize64 >= 0x100000000ULL)
66 		memsize64 = 0xffffffff;
67 
68 	/* finally, setup the timebase */
69 	node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type",
70 					     "cpu", sizeof("cpu"));
71 	if (!node)
72 		fatal("Cannot find cpu node\n");
73 	timebase = fdt_getprop(_dtb_start, node, "timebase-frequency", &size);
74 	if (timebase && (size == 4))
75 		timebase_period_ns = 1000000000 / *timebase;
76 
77 	/* Now we have the memory size; initialize the heap */
78 	simple_alloc_init(_end, memsize64 - (unsigned long)_end, 32, 64);
79 
80 	/* prepare the device tree and find the console */
81 	fdt_init(_dtb_start);
82 
83 	if (platform_specific_init)
84 		platform_specific_init();
85 
86 	serial_console_init();
87 }
88