1 /*
2 * polling mode stateless debugging stuff, originally for NS16550 Serial Ports
3 *
4 * c 2001 PPC 64 Team, IBM Corp
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12 #include <stdarg.h>
13 #include <linux/types.h>
14 #include <linux/sched.h>
15 #include <linux/console.h>
16 #include <linux/init.h>
17 #include <asm/processor.h>
18 #include <asm/udbg.h>
19
20 void (*udbg_putc)(char c);
21 int (*udbg_getc)(void);
22 int (*udbg_getc_poll)(void);
23
24 /*
25 * Early debugging facilities. You can enable _one_ of these via .config,
26 * if you do so your kernel _will not boot_ on anything else. Be careful.
27 */
udbg_early_init(void)28 void __init udbg_early_init(void)
29 {
30 #if defined(CONFIG_PPC_EARLY_DEBUG_LPAR)
31 /* For LPAR machines that have an HVC console on vterm 0 */
32 udbg_init_debug_lpar();
33 #elif defined(CONFIG_PPC_EARLY_DEBUG_G5)
34 /* For use on Apple G5 machines */
35 udbg_init_pmac_realmode();
36 #elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS_PANEL)
37 /* RTAS panel debug */
38 udbg_init_rtas_panel();
39 #elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS_CONSOLE)
40 /* RTAS console debug */
41 udbg_init_rtas_console();
42 #elif defined(CONFIG_PPC_EARLY_DEBUG_MAPLE)
43 /* Maple real mode debug */
44 udbg_init_maple_realmode();
45 #elif defined(CONFIG_PPC_EARLY_DEBUG_ISERIES)
46 /* For iSeries - hit Ctrl-x Ctrl-x to see the output */
47 udbg_init_iseries();
48 #elif defined(CONFIG_PPC_EARLY_DEBUG_BEAT)
49 udbg_init_debug_beat();
50 #elif defined(CONFIG_PPC_EARLY_DEBUG_PAS_REALMODE)
51 udbg_init_pas_realmode();
52 #elif defined(CONFIG_BOOTX_TEXT)
53 udbg_init_btext();
54 #elif defined(CONFIG_PPC_EARLY_DEBUG_44x)
55 /* PPC44x debug */
56 udbg_init_44x_as1();
57 #elif defined(CONFIG_PPC_EARLY_DEBUG_40x)
58 /* PPC40x debug */
59 udbg_init_40x_realmode();
60 #elif defined(CONFIG_PPC_EARLY_DEBUG_CPM)
61 udbg_init_cpm();
62 #endif
63
64 #ifdef CONFIG_PPC_EARLY_DEBUG
65 console_loglevel = 10;
66 #endif
67 }
68
69 /* udbg library, used by xmon et al */
udbg_puts(const char * s)70 void udbg_puts(const char *s)
71 {
72 if (udbg_putc) {
73 char c;
74
75 if (s && *s != '\0') {
76 while ((c = *s++) != '\0')
77 udbg_putc(c);
78 }
79 }
80 #if 0
81 else {
82 printk("%s", s);
83 }
84 #endif
85 }
86
udbg_write(const char * s,int n)87 int udbg_write(const char *s, int n)
88 {
89 int remain = n;
90 char c;
91
92 if (!udbg_putc)
93 return 0;
94
95 if (s && *s != '\0') {
96 while (((c = *s++) != '\0') && (remain-- > 0)) {
97 udbg_putc(c);
98 }
99 }
100
101 return n - remain;
102 }
103
udbg_read(char * buf,int buflen)104 int udbg_read(char *buf, int buflen)
105 {
106 char *p = buf;
107 int i, c;
108
109 if (!udbg_getc)
110 return 0;
111
112 for (i = 0; i < buflen; ++i) {
113 do {
114 c = udbg_getc();
115 if (c == -1 && i == 0)
116 return -1;
117
118 } while (c == 0x11 || c == 0x13);
119 if (c == 0 || c == -1)
120 break;
121 *p++ = c;
122 }
123
124 return i;
125 }
126
127 #define UDBG_BUFSIZE 256
udbg_printf(const char * fmt,...)128 void udbg_printf(const char *fmt, ...)
129 {
130 char buf[UDBG_BUFSIZE];
131 va_list args;
132
133 va_start(args, fmt);
134 vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
135 udbg_puts(buf);
136 va_end(args);
137 }
138
udbg_progress(char * s,unsigned short hex)139 void __init udbg_progress(char *s, unsigned short hex)
140 {
141 udbg_puts(s);
142 udbg_puts("\n");
143 }
144
145 /*
146 * Early boot console based on udbg
147 */
udbg_console_write(struct console * con,const char * s,unsigned int n)148 static void udbg_console_write(struct console *con, const char *s,
149 unsigned int n)
150 {
151 udbg_write(s, n);
152 }
153
154 static struct console udbg_console = {
155 .name = "udbg",
156 .write = udbg_console_write,
157 .flags = CON_PRINTBUFFER | CON_ENABLED | CON_BOOT | CON_ANYTIME,
158 .index = 0,
159 };
160
161 static int early_console_initialized;
162
163 /*
164 * Called by setup_system after ppc_md->probe and ppc_md->early_init.
165 * Call it again after setting udbg_putc in ppc_md->setup_arch.
166 */
register_early_udbg_console(void)167 void __init register_early_udbg_console(void)
168 {
169 if (early_console_initialized)
170 return;
171
172 if (!udbg_putc)
173 return;
174
175 if (strstr(boot_command_line, "udbg-immortal")) {
176 printk(KERN_INFO "early console immortal !\n");
177 udbg_console.flags &= ~CON_BOOT;
178 }
179 early_console_initialized = 1;
180 register_console(&udbg_console);
181 }
182
183 #if 0 /* if you want to use this as a regular output console */
184 console_initcall(register_udbg_console);
185 #endif
186