Robin Getz | 0ae5364 | 2007-10-09 17:24:49 +0800 | [diff] [blame] | 1 | /* |
Robin Getz | 96f1050 | 2009-09-24 14:11:24 +0000 | [diff] [blame] | 2 | * allow a console to be used for early printk |
| 3 | * derived from arch/x86/kernel/early_printk.c |
Robin Getz | 0ae5364 | 2007-10-09 17:24:49 +0800 | [diff] [blame] | 4 | * |
Robin Getz | 96f1050 | 2009-09-24 14:11:24 +0000 | [diff] [blame] | 5 | * Copyright 2007-2009 Analog Devices Inc. |
Robin Getz | 0ae5364 | 2007-10-09 17:24:49 +0800 | [diff] [blame] | 6 | * |
Robin Getz | 96f1050 | 2009-09-24 14:11:24 +0000 | [diff] [blame] | 7 | * Licensed under the GPL-2 |
Robin Getz | 0ae5364 | 2007-10-09 17:24:49 +0800 | [diff] [blame] | 8 | */ |
| 9 | |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/serial_core.h> |
| 13 | #include <linux/console.h> |
| 14 | #include <linux/string.h> |
Robin Getz | 837ec2d | 2009-07-07 20:17:09 +0000 | [diff] [blame] | 15 | #include <linux/reboot.h> |
Robin Getz | 0ae5364 | 2007-10-09 17:24:49 +0800 | [diff] [blame] | 16 | #include <asm/blackfin.h> |
| 17 | #include <asm/irq_handler.h> |
| 18 | #include <asm/early_printk.h> |
| 19 | |
| 20 | #ifdef CONFIG_SERIAL_BFIN |
| 21 | extern struct console *bfin_earlyserial_init(unsigned int port, |
| 22 | unsigned int cflag); |
| 23 | #endif |
Mike Frysinger | a88c71e | 2008-10-10 17:37:52 +0800 | [diff] [blame] | 24 | #ifdef CONFIG_BFIN_JTAG_COMM |
| 25 | extern struct console *bfin_jc_early_init(void); |
| 26 | #endif |
Robin Getz | 0ae5364 | 2007-10-09 17:24:49 +0800 | [diff] [blame] | 27 | |
| 28 | static struct console *early_console; |
| 29 | |
Robin Getz | 337d390 | 2007-10-09 17:31:46 +0800 | [diff] [blame] | 30 | /* Default console */ |
Robin Getz | 0ae5364 | 2007-10-09 17:24:49 +0800 | [diff] [blame] | 31 | #define DEFAULT_PORT 0 |
| 32 | #define DEFAULT_CFLAG CS8|B57600 |
| 33 | |
Robin Getz | 337d390 | 2007-10-09 17:31:46 +0800 | [diff] [blame] | 34 | /* Default console for early crashes */ |
| 35 | #define DEFAULT_EARLY_PORT "serial,uart0,57600" |
| 36 | |
Robin Getz | 0ae5364 | 2007-10-09 17:24:49 +0800 | [diff] [blame] | 37 | #ifdef CONFIG_SERIAL_CORE |
| 38 | /* What should get here is "0,57600" */ |
| 39 | static struct console * __init earlyserial_init(char *buf) |
| 40 | { |
| 41 | int baud, bit; |
| 42 | char parity; |
| 43 | unsigned int serial_port = DEFAULT_PORT; |
| 44 | unsigned int cflag = DEFAULT_CFLAG; |
| 45 | |
| 46 | serial_port = simple_strtoul(buf, &buf, 10); |
| 47 | buf++; |
| 48 | |
| 49 | cflag = 0; |
| 50 | baud = simple_strtoul(buf, &buf, 10); |
| 51 | switch (baud) { |
| 52 | case 1200: |
| 53 | cflag |= B1200; |
| 54 | break; |
| 55 | case 2400: |
| 56 | cflag |= B2400; |
| 57 | break; |
| 58 | case 4800: |
| 59 | cflag |= B4800; |
| 60 | break; |
| 61 | case 9600: |
| 62 | cflag |= B9600; |
| 63 | break; |
| 64 | case 19200: |
| 65 | cflag |= B19200; |
| 66 | break; |
| 67 | case 38400: |
| 68 | cflag |= B38400; |
| 69 | break; |
| 70 | case 115200: |
| 71 | cflag |= B115200; |
| 72 | break; |
| 73 | default: |
| 74 | cflag |= B57600; |
| 75 | } |
| 76 | |
| 77 | parity = buf[0]; |
| 78 | buf++; |
| 79 | switch (parity) { |
| 80 | case 'e': |
| 81 | cflag |= PARENB; |
| 82 | break; |
| 83 | case 'o': |
| 84 | cflag |= PARODD; |
| 85 | break; |
| 86 | } |
| 87 | |
| 88 | bit = simple_strtoul(buf, &buf, 10); |
| 89 | switch (bit) { |
| 90 | case 5: |
| 91 | cflag |= CS5; |
| 92 | break; |
| 93 | case 6: |
Mike Frysinger | 09b7f4a | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 94 | cflag |= CS6; |
Robin Getz | 0ae5364 | 2007-10-09 17:24:49 +0800 | [diff] [blame] | 95 | break; |
| 96 | case 7: |
Mike Frysinger | 09b7f4a | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 97 | cflag |= CS7; |
Robin Getz | 0ae5364 | 2007-10-09 17:24:49 +0800 | [diff] [blame] | 98 | break; |
| 99 | default: |
| 100 | cflag |= CS8; |
| 101 | } |
| 102 | |
| 103 | #ifdef CONFIG_SERIAL_BFIN |
| 104 | return bfin_earlyserial_init(serial_port, cflag); |
| 105 | #else |
| 106 | return NULL; |
| 107 | #endif |
| 108 | |
| 109 | } |
| 110 | #endif |
| 111 | |
| 112 | int __init setup_early_printk(char *buf) |
| 113 | { |
| 114 | |
| 115 | /* Crashing in here would be really bad, so check both the var |
| 116 | and the pointer before we start using it |
| 117 | */ |
| 118 | if (!buf) |
| 119 | return 0; |
| 120 | |
| 121 | if (!*buf) |
| 122 | return 0; |
| 123 | |
| 124 | if (early_console != NULL) |
| 125 | return 0; |
| 126 | |
| 127 | #ifdef CONFIG_SERIAL_BFIN |
| 128 | /* Check for Blackfin Serial */ |
| 129 | if (!strncmp(buf, "serial,uart", 11)) { |
| 130 | buf += 11; |
| 131 | early_console = earlyserial_init(buf); |
| 132 | } |
| 133 | #endif |
Mike Frysinger | a88c71e | 2008-10-10 17:37:52 +0800 | [diff] [blame] | 134 | |
| 135 | #ifdef CONFIG_BFIN_JTAG_COMM |
| 136 | /* Check for Blackfin JTAG */ |
| 137 | if (!strncmp(buf, "jtag", 4)) { |
| 138 | buf += 4; |
| 139 | early_console = bfin_jc_early_init(); |
| 140 | } |
| 141 | #endif |
| 142 | |
Robin Getz | 0ae5364 | 2007-10-09 17:24:49 +0800 | [diff] [blame] | 143 | #ifdef CONFIG_FB |
| 144 | /* TODO: add framebuffer console support */ |
| 145 | #endif |
| 146 | |
| 147 | if (likely(early_console)) { |
| 148 | early_console->flags |= CON_BOOT; |
| 149 | |
| 150 | register_console(early_console); |
| 151 | printk(KERN_INFO "early printk enabled on %s%d\n", |
| 152 | early_console->name, |
| 153 | early_console->index); |
| 154 | } |
| 155 | |
| 156 | return 0; |
| 157 | } |
| 158 | |
Robin Getz | 337d390 | 2007-10-09 17:31:46 +0800 | [diff] [blame] | 159 | /* |
| 160 | * Set up a temporary Event Vector Table, so if something bad happens before |
| 161 | * the kernel is fully started, it doesn't vector off into somewhere we don't |
| 162 | * know |
| 163 | */ |
| 164 | |
| 165 | asmlinkage void __init init_early_exception_vectors(void) |
| 166 | { |
Mike Frysinger | 685a694 | 2009-06-03 00:33:31 +0000 | [diff] [blame] | 167 | u32 evt; |
Robin Getz | 337d390 | 2007-10-09 17:31:46 +0800 | [diff] [blame] | 168 | SSYNC(); |
| 169 | |
Robin Getz | 837ec2d | 2009-07-07 20:17:09 +0000 | [diff] [blame] | 170 | /* |
| 171 | * This starts up the shadow buffer, incase anything crashes before |
| 172 | * setup arch |
| 173 | */ |
| 174 | mark_shadow_error(); |
| 175 | early_shadow_puts(linux_banner); |
| 176 | early_shadow_stamp(); |
| 177 | |
| 178 | if (CPUID != bfin_cpuid()) { |
| 179 | early_shadow_puts("Running on wrong machine type, expected"); |
| 180 | early_shadow_reg(CPUID, 16); |
| 181 | early_shadow_puts(", but running on"); |
| 182 | early_shadow_reg(bfin_cpuid(), 16); |
| 183 | early_shadow_puts("\n"); |
| 184 | } |
| 185 | |
Robin Getz | 337d390 | 2007-10-09 17:31:46 +0800 | [diff] [blame] | 186 | /* cannot program in software: |
| 187 | * evt0 - emulation (jtag) |
| 188 | * evt1 - reset |
| 189 | */ |
Mike Frysinger | 685a694 | 2009-06-03 00:33:31 +0000 | [diff] [blame] | 190 | for (evt = EVT2; evt <= EVT15; evt += 4) |
| 191 | bfin_write32(evt, early_trap); |
Robin Getz | 337d390 | 2007-10-09 17:31:46 +0800 | [diff] [blame] | 192 | CSYNC(); |
| 193 | |
Joe Perches | 79f1ec8 | 2007-12-24 20:03:51 +0800 | [diff] [blame] | 194 | /* Set all the return from interrupt, exception, NMI to a known place |
Robin Getz | 337d390 | 2007-10-09 17:31:46 +0800 | [diff] [blame] | 195 | * so if we do a RETI, RETX or RETN by mistake - we go somewhere known |
| 196 | * Note - don't change RETS - we are in a subroutine, or |
| 197 | * RETE - since it might screw up if emulator is attached |
| 198 | */ |
| 199 | asm("\tRETI = %0; RETX = %0; RETN = %0;\n" |
| 200 | : : "p"(early_trap)); |
| 201 | |
| 202 | } |
| 203 | |
Robin Getz | 837ec2d | 2009-07-07 20:17:09 +0000 | [diff] [blame] | 204 | __attribute__((__noreturn__)) |
Robin Getz | 337d390 | 2007-10-09 17:31:46 +0800 | [diff] [blame] | 205 | asmlinkage void __init early_trap_c(struct pt_regs *fp, void *retaddr) |
| 206 | { |
| 207 | /* This can happen before the uart is initialized, so initialize |
Robin Getz | 54ebae7 | 2009-06-10 06:11:21 +0000 | [diff] [blame] | 208 | * the UART now (but only if we are running on the processor we think |
| 209 | * we are compiled for - otherwise we write to MMRs that don't exist, |
| 210 | * and cause other problems. Nothing comes out the UART, but it does |
| 211 | * end up in the __buf_log. |
Robin Getz | 337d390 | 2007-10-09 17:31:46 +0800 | [diff] [blame] | 212 | */ |
Robin Getz | 54ebae7 | 2009-06-10 06:11:21 +0000 | [diff] [blame] | 213 | if (likely(early_console == NULL) && CPUID == bfin_cpuid()) |
Robin Getz | 337d390 | 2007-10-09 17:31:46 +0800 | [diff] [blame] | 214 | setup_early_printk(DEFAULT_EARLY_PORT); |
| 215 | |
Robin Getz | 837ec2d | 2009-07-07 20:17:09 +0000 | [diff] [blame] | 216 | if (!shadow_console_enabled()) { |
| 217 | /* crap - we crashed before setup_arch() */ |
| 218 | early_shadow_puts("panic before setup_arch\n"); |
| 219 | early_shadow_puts("IPEND:"); |
| 220 | early_shadow_reg(fp->ipend, 16); |
| 221 | if (fp->seqstat & SEQSTAT_EXCAUSE) { |
| 222 | early_shadow_puts("\nEXCAUSE:"); |
| 223 | early_shadow_reg(fp->seqstat & SEQSTAT_EXCAUSE, 8); |
| 224 | } |
| 225 | if (fp->seqstat & SEQSTAT_HWERRCAUSE) { |
| 226 | early_shadow_puts("\nHWERRCAUSE:"); |
| 227 | early_shadow_reg( |
| 228 | (fp->seqstat & SEQSTAT_HWERRCAUSE) >> 14, 8); |
| 229 | } |
| 230 | early_shadow_puts("\nErr @"); |
| 231 | if (fp->ipend & EVT_EVX) |
| 232 | early_shadow_reg(fp->retx, 32); |
| 233 | else |
| 234 | early_shadow_reg(fp->pc, 32); |
| 235 | #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON |
| 236 | early_shadow_puts("\nTrace:"); |
| 237 | if (likely(bfin_read_TBUFSTAT() & TBUFCNT)) { |
| 238 | while (bfin_read_TBUFSTAT() & TBUFCNT) { |
| 239 | early_shadow_puts("\nT :"); |
| 240 | early_shadow_reg(bfin_read_TBUF(), 32); |
| 241 | early_shadow_puts("\n S :"); |
| 242 | early_shadow_reg(bfin_read_TBUF(), 32); |
| 243 | } |
| 244 | } |
| 245 | #endif |
| 246 | early_shadow_puts("\nUse bfin-elf-addr2line to determine " |
| 247 | "function names\n"); |
| 248 | /* |
| 249 | * We should panic(), but we can't - since panic calls printk, |
| 250 | * and printk uses memcpy. |
| 251 | * we want to reboot, but if the machine type is different, |
| 252 | * can't due to machine specific reboot sequences |
| 253 | */ |
| 254 | if (CPUID == bfin_cpuid()) { |
| 255 | early_shadow_puts("Trying to restart\n"); |
| 256 | machine_restart(""); |
| 257 | } |
| 258 | |
| 259 | early_shadow_puts("Halting, since it is not safe to restart\n"); |
| 260 | while (1) |
| 261 | asm volatile ("EMUEXCPT; IDLE;\n"); |
| 262 | |
| 263 | } else { |
| 264 | printk(KERN_EMERG "Early panic\n"); |
| 265 | show_regs(fp); |
| 266 | dump_bfin_trace_buffer(); |
| 267 | } |
Robin Getz | 337d390 | 2007-10-09 17:31:46 +0800 | [diff] [blame] | 268 | |
| 269 | panic("Died early"); |
| 270 | } |
| 271 | |
Robin Getz | 0ae5364 | 2007-10-09 17:24:49 +0800 | [diff] [blame] | 272 | early_param("earlyprintk", setup_early_printk); |