projects/linux·blob master · refs

87 lines · 2.7 KiB

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 <[email protected]>
9 * Grant Likely <[email protected]>
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
21BSS_STACK(4*1024);
22
23extern int platform_specific_init(void) __attribute__((weak));
24
25void 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 < 0)
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}