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 */ 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 #endif 53 } 54 55 /* udbg library, used by xmon et al */ 56 void udbg_puts(const char *s) 57 { 58 if (udbg_putc) { 59 char c; 60 61 if (s && *s != '\0') { 62 while ((c = *s++) != '\0') 63 udbg_putc(c); 64 } 65 } 66 #if 0 67 else { 68 printk("%s", s); 69 } 70 #endif 71 } 72 73 int udbg_write(const char *s, int n) 74 { 75 int remain = n; 76 char c; 77 78 if (!udbg_putc) 79 return 0; 80 81 if (s && *s != '\0') { 82 while (((c = *s++) != '\0') && (remain-- > 0)) { 83 udbg_putc(c); 84 } 85 } 86 87 return n - remain; 88 } 89 90 int udbg_read(char *buf, int buflen) 91 { 92 char *p = buf; 93 int i, c; 94 95 if (!udbg_getc) 96 return 0; 97 98 for (i = 0; i < buflen; ++i) { 99 do { 100 c = udbg_getc(); 101 if (c == -1 && i == 0) 102 return -1; 103 104 } while (c == 0x11 || c == 0x13); 105 if (c == 0 || c == -1) 106 break; 107 *p++ = c; 108 } 109 110 return i; 111 } 112 113 #define UDBG_BUFSIZE 256 114 void udbg_printf(const char *fmt, ...) 115 { 116 char buf[UDBG_BUFSIZE]; 117 va_list args; 118 119 va_start(args, fmt); 120 vsnprintf(buf, UDBG_BUFSIZE, fmt, args); 121 udbg_puts(buf); 122 va_end(args); 123 } 124 125 void __init udbg_progress(char *s, unsigned short hex) 126 { 127 udbg_puts(s); 128 udbg_puts("\n"); 129 } 130 131 /* 132 * Early boot console based on udbg 133 */ 134 static void udbg_console_write(struct console *con, const char *s, 135 unsigned int n) 136 { 137 udbg_write(s, n); 138 } 139 140 static struct console udbg_console = { 141 .name = "udbg", 142 .write = udbg_console_write, 143 .flags = CON_PRINTBUFFER | CON_ENABLED, 144 .index = -1, 145 }; 146 147 static int early_console_initialized; 148 149 void __init disable_early_printk(void) 150 { 151 if (!early_console_initialized) 152 return; 153 if (strstr(saved_command_line, "udbg-immortal")) { 154 printk(KERN_INFO "early console immortal !\n"); 155 return; 156 } 157 unregister_console(&udbg_console); 158 early_console_initialized = 0; 159 } 160 161 /* called by setup_system */ 162 void register_early_udbg_console(void) 163 { 164 if (early_console_initialized) 165 return; 166 early_console_initialized = 1; 167 register_console(&udbg_console); 168 } 169 170 #if 0 /* if you want to use this as a regular output console */ 171 console_initcall(register_udbg_console); 172 #endif 173