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drivers/serial/serial-uclass.c

1    static void serial_find_console_or_panic(void)
2    {
3            const void *blob = gd->fdt_blob;
4            struct udevice *dev;
5            int node;
6    
7            if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
8                    uclass_first_device(UCLASS_SERIAL, &dev);
9                    if (dev) {
10                            gd->cur_serial_dev = dev;
11                            return;
12                    }
13            } else if (CONFIG_IS_ENABLED(OF_CONTROL) && blob) {
14                    /* Check for a chosen console */
15                    node = fdtdec_get_chosen_node(blob, "stdout-path");
16                    if (node < 0) {
17                            const char *str, *p, *name;
18    
19                            /*
20                             * Deal with things like
21                             *      stdout-path = "serial0:115200n8";
22                             *
23                             * We need to look up the alias and then follow it to
24                             * the correct node.
25                             */
26                            str = fdtdec_get_chosen_prop(blob, "stdout-path");
27                            if (str) {
28                                    p = strchr(str, ':');
29                                    name = fdt_get_alias_namelen(blob, str,
30                                                    p ? p - str : strlen(str));
31                                    if (name)
32                                            node = fdt_path_offset(blob, name);
33                            }
34                    }
35                    if (node < 0)
36                            node = fdt_path_offset(blob, "console");
37                    if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node,
38                                                        &dev)) {
39                            gd->cur_serial_dev = dev;
40                            return;
41                    }
42    
43                    /*
44                     * If the console is not marked to be bound before relocation,
45                     * bind it anyway.
46                     */
47                    if (node > 0 &&
48                        !lists_bind_fdt(gd->dm_root, blob, node, &dev)) {
49                            if (!device_probe(dev)) {
50                                    gd->cur_serial_dev = dev;
51                                    return;
52                            }
53                    }
54            }
55            if (!SPL_BUILD || !CONFIG_IS_ENABLED(OF_CONTROL) || !blob) {
56                    /*
57                     * Try to use CONFIG_CONS_INDEX if available (it is numbered
58                     * from 1!).
59                     *
60                     * Failing that, get the device with sequence number 0, or in
61                     * extremis just the first serial device we can find. But we
62                     * insist on having a console (even if it is silent).
63                     */
64    #ifdef CONFIG_CONS_INDEX
65    #define INDEX (CONFIG_CONS_INDEX - 1)
66    #else
67    #define INDEX 0
68    #endif
69                    if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
70                        !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
71                        (!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) {
72                            gd->cur_serial_dev = dev;
73                            return;
74                    }
75    #undef INDEX
76            }
77    
78    #ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
79            panic_str("No serial driver found");
80    #endif
81    }

• 7번 줄은 if문은 수행되지 않습니다.
• 13번 줄의 else if문이 수행됩니다.