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 #elif defined(CONFIG_BOOTX_TEXT) 53 udbg_init_btext(); 54 #endif 55 } 56 57 /* udbg library, used by xmon et al */ 58 void udbg_puts(const char *s) 59 { 60 if (udbg_putc) { 61 char c; 62 63 if (s && *s != '\0') { 64 while ((c = *s++) != '\0') 65 udbg_putc(c); 66 } 67 } 68 #if 0 69 else { 70 printk("%s", s); 71 } 72 #endif 73 } 74 75 int udbg_write(const char *s, int n) 76 { 77 int remain = n; 78 char c; 79 80 if (!udbg_putc) 81 return 0; 82 83 if (s && *s != '\0') { 84 while (((c = *s++) != '\0') && (remain-- > 0)) { 85 udbg_putc(c); 86 } 87 } 88 89 return n - remain; 90 } 91 92 int udbg_read(char *buf, int buflen) 93 { 94 char *p = buf; 95 int i, c; 96 97 if (!udbg_getc) 98 return 0; 99 100 for (i = 0; i < buflen; ++i) { 101 do { 102 c = udbg_getc(); 103 if (c == -1 && i == 0) 104 return -1; 105 106 } while (c == 0x11 || c == 0x13); 107 if (c == 0 || c == -1) 108 break; 109 *p++ = c; 110 } 111 112 return i; 113 } 114 115 #define UDBG_BUFSIZE 256 116 void udbg_printf(const char *fmt, ...) 117 { 118 char buf[UDBG_BUFSIZE]; 119 va_list args; 120 121 va_start(args, fmt); 122 vsnprintf(buf, UDBG_BUFSIZE, fmt, args); 123 udbg_puts(buf); 124 va_end(args); 125 } 126 127 void __init udbg_progress(char *s, unsigned short hex) 128 { 129 udbg_puts(s); 130 udbg_puts("\n"); 131 } 132 133 /* 134 * Early boot console based on udbg 135 */ 136 static void udbg_console_write(struct console *con, const char *s, 137 unsigned int n) 138 { 139 udbg_write(s, n); 140 } 141 142 static struct console udbg_console = { 143 .name = "udbg", 144 .write = udbg_console_write, 145 .flags = CON_PRINTBUFFER | CON_ENABLED, 146 .index = -1, 147 }; 148 149 static int early_console_initialized; 150 151 void __init disable_early_printk(void) 152 { 153 if (!early_console_initialized) 154 return; 155 if (strstr(boot_command_line, "udbg-immortal")) { 156 printk(KERN_INFO "early console immortal !\n"); 157 return; 158 } 159 unregister_console(&udbg_console); 160 early_console_initialized = 0; 161 } 162 163 /* called by setup_system */ 164 void register_early_udbg_console(void) 165 { 166 if (early_console_initialized) 167 return; 168 early_console_initialized = 1; 169 register_console(&udbg_console); 170 } 171 172 #if 0 /* if you want to use this as a regular output console */ 173 console_initcall(register_udbg_console); 174 #endif 175