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 #endif 49 } 50 51 /* udbg library, used by xmon et al */ 52 void udbg_puts(const char *s) 53 { 54 if (udbg_putc) { 55 char c; 56 57 if (s && *s != '\0') { 58 while ((c = *s++) != '\0') 59 udbg_putc(c); 60 } 61 } 62 #if 0 63 else { 64 printk("%s", s); 65 } 66 #endif 67 } 68 69 int udbg_write(const char *s, int n) 70 { 71 int remain = n; 72 char c; 73 74 if (!udbg_putc) 75 return 0; 76 77 if (s && *s != '\0') { 78 while (((c = *s++) != '\0') && (remain-- > 0)) { 79 udbg_putc(c); 80 } 81 } 82 83 return n - remain; 84 } 85 86 int udbg_read(char *buf, int buflen) 87 { 88 char *p = buf; 89 int i, c; 90 91 if (!udbg_getc) 92 return 0; 93 94 for (i = 0; i < buflen; ++i) { 95 do { 96 c = udbg_getc(); 97 if (c == -1 && i == 0) 98 return -1; 99 100 } while (c == 0x11 || c == 0x13); 101 if (c == 0 || c == -1) 102 break; 103 *p++ = c; 104 } 105 106 return i; 107 } 108 109 #define UDBG_BUFSIZE 256 110 void udbg_printf(const char *fmt, ...) 111 { 112 char buf[UDBG_BUFSIZE]; 113 va_list args; 114 115 va_start(args, fmt); 116 vsnprintf(buf, UDBG_BUFSIZE, fmt, args); 117 udbg_puts(buf); 118 va_end(args); 119 } 120 121 void __init udbg_progress(char *s, unsigned short hex) 122 { 123 udbg_puts(s); 124 udbg_puts("\n"); 125 } 126 127 /* 128 * Early boot console based on udbg 129 */ 130 static void udbg_console_write(struct console *con, const char *s, 131 unsigned int n) 132 { 133 udbg_write(s, n); 134 } 135 136 static struct console udbg_console = { 137 .name = "udbg", 138 .write = udbg_console_write, 139 .flags = CON_PRINTBUFFER | CON_ENABLED, 140 .index = -1, 141 }; 142 143 static int early_console_initialized; 144 145 void __init disable_early_printk(void) 146 { 147 if (!early_console_initialized) 148 return; 149 if (strstr(saved_command_line, "udbg-immortal")) { 150 printk(KERN_INFO "early console immortal !\n"); 151 return; 152 } 153 unregister_console(&udbg_console); 154 early_console_initialized = 0; 155 } 156 157 /* called by setup_system */ 158 void register_early_udbg_console(void) 159 { 160 if (early_console_initialized) 161 return; 162 early_console_initialized = 1; 163 register_console(&udbg_console); 164 } 165 166 #if 0 /* if you want to use this as a regular output console */ 167 console_initcall(register_udbg_console); 168 #endif 169