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/config.h> 14 #include <linux/types.h> 15 #include <linux/sched.h> 16 #include <linux/console.h> 17 #include <linux/init.h> 18 #include <asm/processor.h> 19 #include <asm/udbg.h> 20 21 void (*udbg_putc)(char c); 22 int (*udbg_getc)(void); 23 int (*udbg_getc_poll)(void); 24 25 /* 26 * Early debugging facilities. You can enable _one_ of these via .config, 27 * if you do so your kernel _will not boot_ on anything else. Be careful. 28 */ 29 void __init udbg_early_init(void) 30 { 31 #if defined(CONFIG_PPC_EARLY_DEBUG_LPAR) 32 /* For LPAR machines that have an HVC console on vterm 0 */ 33 udbg_init_debug_lpar(); 34 #elif defined(CONFIG_PPC_EARLY_DEBUG_G5) 35 /* For use on Apple G5 machines */ 36 udbg_init_pmac_realmode(); 37 #elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS_PANEL) 38 /* RTAS panel debug */ 39 udbg_init_rtas_panel(); 40 #elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS_CONSOLE) 41 /* RTAS console debug */ 42 udbg_init_rtas_console(); 43 #elif defined(CONFIG_PPC_EARLY_DEBUG_MAPLE) 44 /* Maple real mode debug */ 45 udbg_init_maple_realmode(); 46 #elif defined(CONFIG_PPC_EARLY_DEBUG_ISERIES) 47 /* For iSeries - hit Ctrl-x Ctrl-x to see the output */ 48 udbg_init_iseries(); 49 #endif 50 } 51 52 /* udbg library, used by xmon et al */ 53 void udbg_puts(const char *s) 54 { 55 if (udbg_putc) { 56 char c; 57 58 if (s && *s != '\0') { 59 while ((c = *s++) != '\0') 60 udbg_putc(c); 61 } 62 } 63 #if 0 64 else { 65 printk("%s", s); 66 } 67 #endif 68 } 69 70 int udbg_write(const char *s, int n) 71 { 72 int remain = n; 73 char c; 74 75 if (!udbg_putc) 76 return 0; 77 78 if (s && *s != '\0') { 79 while (((c = *s++) != '\0') && (remain-- > 0)) { 80 udbg_putc(c); 81 } 82 } 83 84 return n - remain; 85 } 86 87 int udbg_read(char *buf, int buflen) 88 { 89 char *p = buf; 90 int i, c; 91 92 if (!udbg_getc) 93 return 0; 94 95 for (i = 0; i < buflen; ++i) { 96 do { 97 c = udbg_getc(); 98 if (c == -1 && i == 0) 99 return -1; 100 101 } while (c == 0x11 || c == 0x13); 102 if (c == 0 || c == -1) 103 break; 104 *p++ = c; 105 } 106 107 return i; 108 } 109 110 #define UDBG_BUFSIZE 256 111 void udbg_printf(const char *fmt, ...) 112 { 113 char buf[UDBG_BUFSIZE]; 114 va_list args; 115 116 va_start(args, fmt); 117 vsnprintf(buf, UDBG_BUFSIZE, fmt, args); 118 udbg_puts(buf); 119 va_end(args); 120 } 121 122 void __init udbg_progress(char *s, unsigned short hex) 123 { 124 udbg_puts(s); 125 udbg_puts("\n"); 126 } 127 128 /* 129 * Early boot console based on udbg 130 */ 131 static void udbg_console_write(struct console *con, const char *s, 132 unsigned int n) 133 { 134 udbg_write(s, n); 135 } 136 137 static struct console udbg_console = { 138 .name = "udbg", 139 .write = udbg_console_write, 140 .flags = CON_PRINTBUFFER | CON_ENABLED, 141 .index = -1, 142 }; 143 144 static int early_console_initialized; 145 146 void __init disable_early_printk(void) 147 { 148 if (!early_console_initialized) 149 return; 150 if (strstr(saved_command_line, "udbg-immortal")) { 151 printk(KERN_INFO "early console immortal !\n"); 152 return; 153 } 154 unregister_console(&udbg_console); 155 early_console_initialized = 0; 156 } 157 158 /* called by setup_system */ 159 void register_early_udbg_console(void) 160 { 161 if (early_console_initialized) 162 return; 163 early_console_initialized = 1; 164 register_console(&udbg_console); 165 } 166 167 #if 0 /* if you want to use this as a regular output console */ 168 console_initcall(register_udbg_console); 169 #endif 170