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