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1#include "boot.h"
2
3#define DEFAULT_SERIAL_PORT 0x3f8 /* ttyS0 */
4
5#define XMTRDY 0x20
6
7#define DLAB 0x80
8
9#define TXR 0 /* Transmit register (WRITE) */
10#define RXR 0 /* Receive register (READ) */
11#define IER 1 /* Interrupt Enable */
12#define IIR 2 /* Interrupt ID */
13#define FCR 2 /* FIFO control */
14#define LCR 3 /* Line control */
15#define MCR 4 /* Modem control */
16#define LSR 5 /* Line Status */
17#define MSR 6 /* Modem Status */
18#define DLL 0 /* Divisor Latch Low */
19#define DLH 1 /* Divisor latch High */
20
21#define DEFAULT_BAUD 9600
22
23static void early_serial_init(int port, int baud)
24{
25 unsigned char c;
26 unsigned divisor;
27
28 outb(0x3, port + LCR); /* 8n1 */
29 outb(0, port + IER); /* no interrupt */
30 outb(0, port + FCR); /* no fifo */
31 outb(0x3, port + MCR); /* DTR + RTS */
32
33 divisor = 115200 / baud;
34 c = inb(port + LCR);
35 outb(c | DLAB, port + LCR);
36 outb(divisor & 0xff, port + DLL);
37 outb((divisor >> 8) & 0xff, port + DLH);
38 outb(c & ~DLAB, port + LCR);
39
40 early_serial_base = port;
41}
42
43static void parse_earlyprintk(void)
44{
45 int baud = DEFAULT_BAUD;
46 char arg[32];
47 int pos = 0;
48 int port = 0;
49
50 if (cmdline_find_option("earlyprintk", arg, sizeof arg) > 0) {
51 char *e;
52
53 if (!strncmp(arg, "serial", 6)) {
54 port = DEFAULT_SERIAL_PORT;
55 pos += 6;
56 }
57
58 if (arg[pos] == ',')
59 pos++;
60
61 /*
62 * make sure we have
63 * "serial,0x3f8,115200"
64 * "serial,ttyS0,115200"
65 * "ttyS0,115200"
66 */
67 if (pos == 7 && !strncmp(arg + pos, "0x", 2)) {
68 port = simple_strtoull(arg + pos, &e, 16);
69 if (port == 0 || arg + pos == e)
70 port = DEFAULT_SERIAL_PORT;
71 else
72 pos = e - arg;
73 } else if (!strncmp(arg + pos, "ttyS", 4)) {
74 static const int bases[] = { 0x3f8, 0x2f8 };
75 int idx = 0;
76
77 if (!strncmp(arg + pos, "ttyS", 4))
78 pos += 4;
79
80 if (arg[pos++] == '1')
81 idx = 1;
82
83 port = bases[idx];
84 }
85
86 if (arg[pos] == ',')
87 pos++;
88
89 baud = simple_strtoull(arg + pos, &e, 0);
90 if (baud == 0 || arg + pos == e)
91 baud = DEFAULT_BAUD;
92 }
93
94 if (port)
95 early_serial_init(port, baud);
96}
97
98#define BASE_BAUD (1843200/16)
99static unsigned int probe_baud(int port)
100{
101 unsigned char lcr, dll, dlh;
102 unsigned int quot;
103
104 lcr = inb(port + LCR);
105 outb(lcr | DLAB, port + LCR);
106 dll = inb(port + DLL);
107 dlh = inb(port + DLH);
108 outb(lcr, port + LCR);
109 quot = (dlh << 8) | dll;
110
111 return BASE_BAUD / quot;
112}
113
114static void parse_console_uart8250(void)
115{
116 char optstr[64], *options;
117 int baud = DEFAULT_BAUD;
118 int port = 0;
119
120 /*
121 * console=uart8250,io,0x3f8,115200n8
122 * need to make sure it is last one console !
123 */
124 if (cmdline_find_option("console", optstr, sizeof optstr) <= 0)
125 return;
126
127 options = optstr;
128
129 if (!strncmp(options, "uart8250,io,", 12))
130 port = simple_strtoull(options + 12, &options, 0);
131 else if (!strncmp(options, "uart,io,", 8))
132 port = simple_strtoull(options + 8, &options, 0);
133 else
134 return;
135
136 if (options && (options[0] == ','))
137 baud = simple_strtoull(options + 1, &options, 0);
138 else
139 baud = probe_baud(port);
140
141 if (port)
142 early_serial_init(port, baud);
143}
144
145void console_init(void)
146{
147 parse_earlyprintk();
148
149 if (!early_serial_base)
150 parse_console_uart8250();
151}
1#include "boot.h"
2
3#define DEFAULT_SERIAL_PORT 0x3f8 /* ttyS0 */
4
5#define DLAB 0x80
6
7#define TXR 0 /* Transmit register (WRITE) */
8#define RXR 0 /* Receive register (READ) */
9#define IER 1 /* Interrupt Enable */
10#define IIR 2 /* Interrupt ID */
11#define FCR 2 /* FIFO control */
12#define LCR 3 /* Line control */
13#define MCR 4 /* Modem control */
14#define LSR 5 /* Line Status */
15#define MSR 6 /* Modem Status */
16#define DLL 0 /* Divisor Latch Low */
17#define DLH 1 /* Divisor latch High */
18
19#define DEFAULT_BAUD 9600
20
21static void early_serial_init(int port, int baud)
22{
23 unsigned char c;
24 unsigned divisor;
25
26 outb(0x3, port + LCR); /* 8n1 */
27 outb(0, port + IER); /* no interrupt */
28 outb(0, port + FCR); /* no fifo */
29 outb(0x3, port + MCR); /* DTR + RTS */
30
31 divisor = 115200 / baud;
32 c = inb(port + LCR);
33 outb(c | DLAB, port + LCR);
34 outb(divisor & 0xff, port + DLL);
35 outb((divisor >> 8) & 0xff, port + DLH);
36 outb(c & ~DLAB, port + LCR);
37
38 early_serial_base = port;
39}
40
41static void parse_earlyprintk(void)
42{
43 int baud = DEFAULT_BAUD;
44 char arg[32];
45 int pos = 0;
46 int port = 0;
47
48 if (cmdline_find_option("earlyprintk", arg, sizeof arg) > 0) {
49 char *e;
50
51 if (!strncmp(arg, "serial", 6)) {
52 port = DEFAULT_SERIAL_PORT;
53 pos += 6;
54 }
55
56 if (arg[pos] == ',')
57 pos++;
58
59 /*
60 * make sure we have
61 * "serial,0x3f8,115200"
62 * "serial,ttyS0,115200"
63 * "ttyS0,115200"
64 */
65 if (pos == 7 && !strncmp(arg + pos, "0x", 2)) {
66 port = simple_strtoull(arg + pos, &e, 16);
67 if (port == 0 || arg + pos == e)
68 port = DEFAULT_SERIAL_PORT;
69 else
70 pos = e - arg;
71 } else if (!strncmp(arg + pos, "ttyS", 4)) {
72 static const int bases[] = { 0x3f8, 0x2f8 };
73 int idx = 0;
74
75 /* += strlen("ttyS"); */
76 pos += 4;
77
78 if (arg[pos++] == '1')
79 idx = 1;
80
81 port = bases[idx];
82 }
83
84 if (arg[pos] == ',')
85 pos++;
86
87 baud = simple_strtoull(arg + pos, &e, 0);
88 if (baud == 0 || arg + pos == e)
89 baud = DEFAULT_BAUD;
90 }
91
92 if (port)
93 early_serial_init(port, baud);
94}
95
96#define BASE_BAUD (1843200/16)
97static unsigned int probe_baud(int port)
98{
99 unsigned char lcr, dll, dlh;
100 unsigned int quot;
101
102 lcr = inb(port + LCR);
103 outb(lcr | DLAB, port + LCR);
104 dll = inb(port + DLL);
105 dlh = inb(port + DLH);
106 outb(lcr, port + LCR);
107 quot = (dlh << 8) | dll;
108
109 return BASE_BAUD / quot;
110}
111
112static void parse_console_uart8250(void)
113{
114 char optstr[64], *options;
115 int baud = DEFAULT_BAUD;
116 int port = 0;
117
118 /*
119 * console=uart8250,io,0x3f8,115200n8
120 * need to make sure it is last one console !
121 */
122 if (cmdline_find_option("console", optstr, sizeof optstr) <= 0)
123 return;
124
125 options = optstr;
126
127 if (!strncmp(options, "uart8250,io,", 12))
128 port = simple_strtoull(options + 12, &options, 0);
129 else if (!strncmp(options, "uart,io,", 8))
130 port = simple_strtoull(options + 8, &options, 0);
131 else
132 return;
133
134 if (options && (options[0] == ','))
135 baud = simple_strtoull(options + 1, &options, 0);
136 else
137 baud = probe_baud(port);
138
139 if (port)
140 early_serial_init(port, baud);
141}
142
143void console_init(void)
144{
145 parse_earlyprintk();
146
147 if (!early_serial_base)
148 parse_console_uart8250();
149}