1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * polling mode stateless debugging stuff, originally for NS16550 Serial Ports 4 * 5 * c 2001 PPC 64 Team, IBM Corp 6 */ 7 8 #include <linux/stdarg.h> 9 #include <linux/types.h> 10 #include <linux/sched.h> 11 #include <linux/console.h> 12 #include <linux/init.h> 13 #include <asm/processor.h> 14 #include <asm/udbg.h> 15 16 void (*udbg_putc)(char c); 17 void (*udbg_flush)(void); 18 int (*udbg_getc)(void); 19 int (*udbg_getc_poll)(void); 20 21 /* 22 * Early debugging facilities. You can enable _one_ of these via .config, 23 * if you do so your kernel _will not boot_ on anything else. Be careful. 24 */ 25 void __init udbg_early_init(void) 26 { 27 #if defined(CONFIG_PPC_EARLY_DEBUG_LPAR) 28 /* For LPAR machines that have an HVC console on vterm 0 */ 29 udbg_init_debug_lpar(); 30 #elif defined(CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI) 31 /* For LPAR machines that have an HVSI console on vterm 0 */ 32 udbg_init_debug_lpar_hvsi(); 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_PAS_REALMODE) 40 udbg_init_pas_realmode(); 41 #elif defined(CONFIG_PPC_EARLY_DEBUG_BOOTX) 42 udbg_init_btext(); 43 #elif defined(CONFIG_PPC_EARLY_DEBUG_44x) 44 /* PPC44x debug */ 45 udbg_init_44x_as1(); 46 #elif defined(CONFIG_PPC_EARLY_DEBUG_CPM) 47 udbg_init_cpm(); 48 #elif defined(CONFIG_PPC_EARLY_DEBUG_USBGECKO) 49 udbg_init_usbgecko(); 50 #elif defined(CONFIG_PPC_EARLY_DEBUG_MEMCONS) 51 /* In memory console */ 52 udbg_init_memcons(); 53 #elif defined(CONFIG_PPC_EARLY_DEBUG_EHV_BC) 54 udbg_init_ehv_bc(); 55 #elif defined(CONFIG_PPC_EARLY_DEBUG_PS3GELIC) 56 udbg_init_ps3gelic(); 57 #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_RAW) 58 udbg_init_debug_opal_raw(); 59 #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI) 60 udbg_init_debug_opal_hvsi(); 61 #elif defined(CONFIG_PPC_EARLY_DEBUG_16550) 62 udbg_init_debug_16550(); 63 #endif 64 65 #ifdef CONFIG_PPC_EARLY_DEBUG 66 console_loglevel = CONSOLE_LOGLEVEL_DEBUG; 67 68 register_early_udbg_console(); 69 #endif 70 } 71 72 /* udbg library, used by xmon et al */ 73 void udbg_puts(const char *s) 74 { 75 if (udbg_putc) { 76 char c; 77 78 if (s && *s != '\0') { 79 while ((c = *s++) != '\0') 80 udbg_putc(c); 81 } 82 83 if (udbg_flush) 84 udbg_flush(); 85 } 86 #if 0 87 else { 88 printk("%s", s); 89 } 90 #endif 91 } 92 93 int udbg_write(const char *s, int n) 94 { 95 int remain = n; 96 char c; 97 98 if (!udbg_putc) 99 return 0; 100 101 if (s && *s != '\0') { 102 while (((c = *s++) != '\0') && (remain-- > 0)) { 103 udbg_putc(c); 104 } 105 } 106 107 if (udbg_flush) 108 udbg_flush(); 109 110 return n - remain; 111 } 112 113 #define UDBG_BUFSIZE 256 114 void udbg_printf(const char *fmt, ...) 115 { 116 if (udbg_putc) { 117 char buf[UDBG_BUFSIZE]; 118 va_list args; 119 120 va_start(args, fmt); 121 vsnprintf(buf, UDBG_BUFSIZE, fmt, args); 122 udbg_puts(buf); 123 va_end(args); 124 } 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 | CON_BOOT | CON_ANYTIME, 146 .index = 0, 147 }; 148 149 /* 150 * Called by setup_system after ppc_md->probe and ppc_md->early_init. 151 * Call it again after setting udbg_putc in ppc_md->setup_arch. 152 */ 153 void __init register_early_udbg_console(void) 154 { 155 if (early_console) 156 return; 157 158 if (!udbg_putc) 159 return; 160 161 if (strstr(boot_command_line, "udbg-immortal")) { 162 printk(KERN_INFO "early console immortal !\n"); 163 udbg_console.flags &= ~CON_BOOT; 164 } 165 early_console = &udbg_console; 166 register_console(&udbg_console); 167 } 168 169 #if 0 /* if you want to use this as a regular output console */ 170 console_initcall(register_udbg_console); 171 #endif 172