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 #elif defined(CONFIG_PPC_EARLY_DEBUG_44x) 55 /* PPC44x debug */ 56 udbg_init_44x_as1(); 57 #elif defined(CONFIG_PPC_EARLY_DEBUG_CPM) 58 udbg_init_cpm(); 59 #endif 60 } 61 62 /* udbg library, used by xmon et al */ 63 void udbg_puts(const char *s) 64 { 65 if (udbg_putc) { 66 char c; 67 68 if (s && *s != '\0') { 69 while ((c = *s++) != '\0') 70 udbg_putc(c); 71 } 72 } 73 #if 0 74 else { 75 printk("%s", s); 76 } 77 #endif 78 } 79 80 int udbg_write(const char *s, int n) 81 { 82 int remain = n; 83 char c; 84 85 if (!udbg_putc) 86 return 0; 87 88 if (s && *s != '\0') { 89 while (((c = *s++) != '\0') && (remain-- > 0)) { 90 udbg_putc(c); 91 } 92 } 93 94 return n - remain; 95 } 96 97 int udbg_read(char *buf, int buflen) 98 { 99 char *p = buf; 100 int i, c; 101 102 if (!udbg_getc) 103 return 0; 104 105 for (i = 0; i < buflen; ++i) { 106 do { 107 c = udbg_getc(); 108 if (c == -1 && i == 0) 109 return -1; 110 111 } while (c == 0x11 || c == 0x13); 112 if (c == 0 || c == -1) 113 break; 114 *p++ = c; 115 } 116 117 return i; 118 } 119 120 #define UDBG_BUFSIZE 256 121 void udbg_printf(const char *fmt, ...) 122 { 123 char buf[UDBG_BUFSIZE]; 124 va_list args; 125 126 va_start(args, fmt); 127 vsnprintf(buf, UDBG_BUFSIZE, fmt, args); 128 udbg_puts(buf); 129 va_end(args); 130 } 131 132 void __init udbg_progress(char *s, unsigned short hex) 133 { 134 udbg_puts(s); 135 udbg_puts("\n"); 136 } 137 138 /* 139 * Early boot console based on udbg 140 */ 141 static void udbg_console_write(struct console *con, const char *s, 142 unsigned int n) 143 { 144 udbg_write(s, n); 145 } 146 147 static struct console udbg_console = { 148 .name = "udbg", 149 .write = udbg_console_write, 150 .flags = CON_PRINTBUFFER | CON_ENABLED | CON_BOOT, 151 .index = -1, 152 }; 153 154 static int early_console_initialized; 155 156 /* 157 * Called by setup_system after ppc_md->probe and ppc_md->early_init. 158 * Call it again after setting udbg_putc in ppc_md->setup_arch. 159 */ 160 void __init register_early_udbg_console(void) 161 { 162 if (early_console_initialized) 163 return; 164 165 if (!udbg_putc) 166 return; 167 168 if (strstr(boot_command_line, "udbg-immortal")) { 169 printk(KERN_INFO "early console immortal !\n"); 170 udbg_console.flags &= ~CON_BOOT; 171 } 172 early_console_initialized = 1; 173 register_console(&udbg_console); 174 } 175 176 #if 0 /* if you want to use this as a regular output console */ 177 console_initcall(register_udbg_console); 178 #endif 179