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 <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) 37 /* RTAS panel debug */ 38 udbg_init_rtas(); 39 #elif defined(CONFIG_PPC_EARLY_DEBUG_MAPLE) 40 /* Maple real mode debug */ 41 udbg_init_maple_realmode(); 42 #elif defined(CONFIG_PPC_EARLY_DEBUG_ISERIES) 43 /* For iSeries - hit Ctrl-x Ctrl-x to see the output */ 44 udbg_init_iseries(); 45 #endif 46 } 47 48 /* udbg library, used by xmon et al */ 49 void udbg_puts(const char *s) 50 { 51 if (udbg_putc) { 52 char c; 53 54 if (s && *s != '\0') { 55 while ((c = *s++) != '\0') 56 udbg_putc(c); 57 } 58 } 59 #if 0 60 else { 61 printk("%s", s); 62 } 63 #endif 64 } 65 66 int udbg_write(const char *s, int n) 67 { 68 int remain = n; 69 char c; 70 71 if (!udbg_putc) 72 return 0; 73 74 if (s && *s != '\0') { 75 while (((c = *s++) != '\0') && (remain-- > 0)) { 76 udbg_putc(c); 77 } 78 } 79 80 return n - remain; 81 } 82 83 int udbg_read(char *buf, int buflen) 84 { 85 char *p = buf; 86 int i, c; 87 88 if (!udbg_getc) 89 return 0; 90 91 for (i = 0; i < buflen; ++i) { 92 do { 93 c = udbg_getc(); 94 if (c == -1 && i == 0) 95 return -1; 96 97 } while (c == 0x11 || c == 0x13); 98 if (c == 0 || c == -1) 99 break; 100 *p++ = c; 101 } 102 103 return i; 104 } 105 106 #define UDBG_BUFSIZE 256 107 void udbg_printf(const char *fmt, ...) 108 { 109 char buf[UDBG_BUFSIZE]; 110 va_list args; 111 112 va_start(args, fmt); 113 vsnprintf(buf, UDBG_BUFSIZE, fmt, args); 114 udbg_puts(buf); 115 va_end(args); 116 } 117 118 void __init udbg_progress(char *s, unsigned short hex) 119 { 120 udbg_puts(s); 121 udbg_puts("\n"); 122 } 123 124 /* 125 * Early boot console based on udbg 126 */ 127 static void udbg_console_write(struct console *con, const char *s, 128 unsigned int n) 129 { 130 udbg_write(s, n); 131 } 132 133 static struct console udbg_console = { 134 .name = "udbg", 135 .write = udbg_console_write, 136 .flags = CON_PRINTBUFFER | CON_ENABLED, 137 .index = -1, 138 }; 139 140 static int early_console_initialized; 141 142 void __init disable_early_printk(void) 143 { 144 #if 1 145 if (!early_console_initialized) 146 return; 147 unregister_console(&udbg_console); 148 early_console_initialized = 0; 149 #endif 150 } 151 152 /* called by setup_system */ 153 void register_early_udbg_console(void) 154 { 155 if (early_console_initialized) 156 return; 157 early_console_initialized = 1; 158 register_console(&udbg_console); 159 } 160 161 #if 0 /* if you want to use this as a regular output console */ 162 console_initcall(register_udbg_console); 163 #endif 164