Commit | Line | Data |
---|---|---|
0ae53640 | 1 | /* |
96f1050d RG |
2 | * allow a console to be used for early printk |
3 | * derived from arch/x86/kernel/early_printk.c | |
0ae53640 | 4 | * |
96f1050d | 5 | * Copyright 2007-2009 Analog Devices Inc. |
0ae53640 | 6 | * |
96f1050d | 7 | * Licensed under the GPL-2 |
0ae53640 RG |
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> | |
837ec2d5 | 15 | #include <linux/reboot.h> |
0ae53640 RG |
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 | |
a88c71e4 MF |
24 | #ifdef CONFIG_BFIN_JTAG_COMM |
25 | extern struct console *bfin_jc_early_init(void); | |
26 | #endif | |
0ae53640 RG |
27 | |
28 | static struct console *early_console; | |
29 | ||
337d390b | 30 | /* Default console */ |
0ae53640 RG |
31 | #define DEFAULT_PORT 0 |
32 | #define DEFAULT_CFLAG CS8|B57600 | |
33 | ||
337d390b RG |
34 | /* Default console for early crashes */ |
35 | #define DEFAULT_EARLY_PORT "serial,uart0,57600" | |
36 | ||
0ae53640 RG |
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: | |
09b7f4ad | 94 | cflag |= CS6; |
0ae53640 RG |
95 | break; |
96 | case 7: | |
09b7f4ad | 97 | cflag |= CS7; |
0ae53640 RG |
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 | |
a88c71e4 MF |
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 | ||
0ae53640 RG |
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 | ||
337d390b RG |
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 | { | |
685a694f | 167 | u32 evt; |
337d390b RG |
168 | SSYNC(); |
169 | ||
837ec2d5 RG |
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 | ||
337d390b RG |
186 | /* cannot program in software: |
187 | * evt0 - emulation (jtag) | |
188 | * evt1 - reset | |
189 | */ | |
685a694f MF |
190 | for (evt = EVT2; evt <= EVT15; evt += 4) |
191 | bfin_write32(evt, early_trap); | |
337d390b RG |
192 | CSYNC(); |
193 | ||
79f1ec86 | 194 | /* Set all the return from interrupt, exception, NMI to a known place |
337d390b RG |
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 | ||
837ec2d5 | 204 | __attribute__((__noreturn__)) |
337d390b RG |
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 | |
54ebae71 RG |
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. | |
337d390b | 212 | */ |
54ebae71 | 213 | if (likely(early_console == NULL) && CPUID == bfin_cpuid()) |
337d390b RG |
214 | setup_early_printk(DEFAULT_EARLY_PORT); |
215 | ||
837ec2d5 RG |
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 | } | |
337d390b RG |
268 | |
269 | panic("Died early"); | |
270 | } | |
271 | ||
0ae53640 | 272 | early_param("earlyprintk", setup_early_printk); |