summaryrefslogtreecommitdiff
path: root/util/romcc/tests/hello_world1.c
blob: b5ce540dc958f8d307663921d54fc40a5c03216f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
void outb(unsigned char value, unsigned short port)
{
	__builtin_outb(value, port);
}

unsigned char inb(unsigned short port)
{
	return __builtin_inb(port);
}

/* Base Address */
#ifndef CONFIG_TTYS0_BASE
#define CONFIG_TTYS0_BASE 0x3f8
#endif

#ifndef CONFIG_TTYS0_BAUD
#define CONFIG_TTYS0_BAUD 115200
#endif

#if ((115200%CONFIG_TTYS0_BAUD) != 0)
#error Bad ttys0 baud rate
#endif

#if CONFIG_TTYS0_BAUD == 115200
#define CONFIG_TTYS0_DIV (1)
#else
#define CONFIG_TTYS0_DIV	(115200/CONFIG_TTYS0_BAUD)
#endif

/* Line Control Settings */
#ifndef CONFIG_TTYS0_LCS
/* Set 8bit, 1 stop bit, no parity */
#define CONFIG_TTYS0_LCS	0x3
#endif

#define UART_LCS	CONFIG_TTYS0_LCS

/* Data */
#define UART_RBR 0x00
#define UART_TBR 0x00

/* Control */
#define UART_IER 0x01
#define UART_IIR 0x02
#define UART_FCR 0x02
#define UART_LCR 0x03
#define UART_MCR 0x04
#define UART_DLL 0x00
#define UART_DLM 0x01

/* Status */
#define UART_LSR 0x05
#define UART_MSR 0x06
#define UART_SCR 0x07

int uart_can_tx_byte(void)
{
	return inb(CONFIG_TTYS0_BASE + UART_LSR) & 0x20;
}

void uart_wait_to_tx_byte(void)
{
	while(!uart_can_tx_byte())
		;
}

void uart_wait_until_sent(void)
{
	while(!(inb(CONFIG_TTYS0_BASE + UART_LSR) & 0x40)) 
		;
}

static void uart_tx_byte(unsigned char data)
{
	uart_wait_to_tx_byte();
	outb(data, CONFIG_TTYS0_BASE + UART_TBR);
	/* Make certain the data clears the fifos */
	uart_wait_until_sent();
}


void uart_init(void)
{
	/* disable interrupts */
	outb(0x0, CONFIG_TTYS0_BASE + UART_IER);
	/* enable fifo's */
	outb(0x01, CONFIG_TTYS0_BASE + UART_FCR);
	/* Set Baud Rate Divisor to 12 ==> 115200 Baud */
	outb(0x80 | UART_LCS, CONFIG_TTYS0_BASE + UART_LCR);
	outb(CONFIG_TTYS0_DIV & 0xFF,   CONFIG_TTYS0_BASE + UART_DLL);
	outb((CONFIG_TTYS0_DIV >> 8) & 0xFF,    CONFIG_TTYS0_BASE + UART_DLM);
	outb(UART_LCS, CONFIG_TTYS0_BASE + UART_LCR);
}


void __console_tx_char(unsigned char byte)
{
	uart_tx_byte(byte);
		
}

void __console_tx_string(char *str)
{
	unsigned char ch;
	while((ch = *str++) != '\0') {
		__console_tx_char(ch);
	}
}


void print_debug_char(unsigned char byte) { __console_tx_char(byte); }
void print_debug(char *str) { __console_tx_string(str); }

void main(void)
{
	static const char msg[] = "hello world\r\n";
	uart_init();
#if 0
	print_debug(msg);
#endif
#if 1
	print_debug("hello world\r\n");
	print_debug("how are you today\r\n");
#endif
	while(1) {
		;
	}
}