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 | 27 | |
337d390b | 28 | /* Default console */ |
0ae53640 RG |
29 | #define DEFAULT_PORT 0 |
30 | #define DEFAULT_CFLAG CS8|B57600 | |
31 | ||
337d390b RG |
32 | /* Default console for early crashes */ |
33 | #define DEFAULT_EARLY_PORT "serial,uart0,57600" | |
34 | ||
0ae53640 RG |
35 | #ifdef CONFIG_SERIAL_CORE |
36 | /* What should get here is "0,57600" */ | |
37 | static struct console * __init earlyserial_init(char *buf) | |
38 | { | |
39 | int baud, bit; | |
40 | char parity; | |
41 | unsigned int serial_port = DEFAULT_PORT; | |
42 | unsigned int cflag = DEFAULT_CFLAG; | |
43 | ||
44 | serial_port = simple_strtoul(buf, &buf, 10); | |
45 | buf++; | |
46 | ||
47 | cflag = 0; | |
48 | baud = simple_strtoul(buf, &buf, 10); | |
49 | switch (baud) { | |
50 | case 1200: | |
51 | cflag |= B1200; | |
52 | break; | |
53 | case 2400: | |
54 | cflag |= B2400; | |
55 | break; | |
56 | case 4800: | |
57 | cflag |= B4800; | |
58 | break; | |
59 | case 9600: | |
60 | cflag |= B9600; | |
61 | break; | |
62 | case 19200: | |
63 | cflag |= B19200; | |
64 | break; | |
65 | case 38400: | |
66 | cflag |= B38400; | |
67 | break; | |
68 | case 115200: | |
69 | cflag |= B115200; | |
70 | break; | |
71 | default: | |
72 | cflag |= B57600; | |
73 | } | |
74 | ||
75 | parity = buf[0]; | |
76 | buf++; | |
77 | switch (parity) { | |
78 | case 'e': | |
79 | cflag |= PARENB; | |
80 | break; | |
81 | case 'o': | |
82 | cflag |= PARODD; | |
83 | break; | |
84 | } | |
85 | ||
86 | bit = simple_strtoul(buf, &buf, 10); | |
87 | switch (bit) { | |
88 | case 5: | |
89 | cflag |= CS5; | |
90 | break; | |
91 | case 6: | |
09b7f4ad | 92 | cflag |= CS6; |
0ae53640 RG |
93 | break; |
94 | case 7: | |
09b7f4ad | 95 | cflag |= CS7; |
0ae53640 RG |
96 | break; |
97 | default: | |
98 | cflag |= CS8; | |
99 | } | |
100 | ||
101 | #ifdef CONFIG_SERIAL_BFIN | |
102 | return bfin_earlyserial_init(serial_port, cflag); | |
103 | #else | |
104 | return NULL; | |
105 | #endif | |
106 | ||
107 | } | |
108 | #endif | |
109 | ||
110 | int __init setup_early_printk(char *buf) | |
111 | { | |
112 | ||
113 | /* Crashing in here would be really bad, so check both the var | |
114 | and the pointer before we start using it | |
115 | */ | |
116 | if (!buf) | |
117 | return 0; | |
118 | ||
119 | if (!*buf) | |
120 | return 0; | |
121 | ||
122 | if (early_console != NULL) | |
123 | return 0; | |
124 | ||
125 | #ifdef CONFIG_SERIAL_BFIN | |
126 | /* Check for Blackfin Serial */ | |
127 | if (!strncmp(buf, "serial,uart", 11)) { | |
128 | buf += 11; | |
129 | early_console = earlyserial_init(buf); | |
130 | } | |
131 | #endif | |
a88c71e4 MF |
132 | |
133 | #ifdef CONFIG_BFIN_JTAG_COMM | |
134 | /* Check for Blackfin JTAG */ | |
135 | if (!strncmp(buf, "jtag", 4)) { | |
136 | buf += 4; | |
137 | early_console = bfin_jc_early_init(); | |
138 | } | |
139 | #endif | |
140 | ||
0ae53640 RG |
141 | #ifdef CONFIG_FB |
142 | /* TODO: add framebuffer console support */ | |
143 | #endif | |
144 | ||
145 | if (likely(early_console)) { | |
146 | early_console->flags |= CON_BOOT; | |
147 | ||
148 | register_console(early_console); | |
149 | printk(KERN_INFO "early printk enabled on %s%d\n", | |
150 | early_console->name, | |
151 | early_console->index); | |
152 | } | |
153 | ||
154 | return 0; | |
155 | } | |
156 | ||
337d390b RG |
157 | /* |
158 | * Set up a temporary Event Vector Table, so if something bad happens before | |
159 | * the kernel is fully started, it doesn't vector off into somewhere we don't | |
160 | * know | |
161 | */ | |
162 | ||
163 | asmlinkage void __init init_early_exception_vectors(void) | |
164 | { | |
685a694f | 165 | u32 evt; |
337d390b RG |
166 | SSYNC(); |
167 | ||
837ec2d5 RG |
168 | /* |
169 | * This starts up the shadow buffer, incase anything crashes before | |
170 | * setup arch | |
171 | */ | |
172 | mark_shadow_error(); | |
173 | early_shadow_puts(linux_banner); | |
174 | early_shadow_stamp(); | |
175 | ||
176 | if (CPUID != bfin_cpuid()) { | |
177 | early_shadow_puts("Running on wrong machine type, expected"); | |
178 | early_shadow_reg(CPUID, 16); | |
179 | early_shadow_puts(", but running on"); | |
180 | early_shadow_reg(bfin_cpuid(), 16); | |
181 | early_shadow_puts("\n"); | |
182 | } | |
183 | ||
337d390b RG |
184 | /* cannot program in software: |
185 | * evt0 - emulation (jtag) | |
186 | * evt1 - reset | |
187 | */ | |
685a694f MF |
188 | for (evt = EVT2; evt <= EVT15; evt += 4) |
189 | bfin_write32(evt, early_trap); | |
337d390b RG |
190 | CSYNC(); |
191 | ||
79f1ec86 | 192 | /* Set all the return from interrupt, exception, NMI to a known place |
337d390b RG |
193 | * so if we do a RETI, RETX or RETN by mistake - we go somewhere known |
194 | * Note - don't change RETS - we are in a subroutine, or | |
195 | * RETE - since it might screw up if emulator is attached | |
196 | */ | |
197 | asm("\tRETI = %0; RETX = %0; RETN = %0;\n" | |
198 | : : "p"(early_trap)); | |
199 | ||
200 | } | |
201 | ||
837ec2d5 | 202 | __attribute__((__noreturn__)) |
337d390b RG |
203 | asmlinkage void __init early_trap_c(struct pt_regs *fp, void *retaddr) |
204 | { | |
205 | /* This can happen before the uart is initialized, so initialize | |
54ebae71 RG |
206 | * the UART now (but only if we are running on the processor we think |
207 | * we are compiled for - otherwise we write to MMRs that don't exist, | |
208 | * and cause other problems. Nothing comes out the UART, but it does | |
209 | * end up in the __buf_log. | |
337d390b | 210 | */ |
54ebae71 | 211 | if (likely(early_console == NULL) && CPUID == bfin_cpuid()) |
337d390b RG |
212 | setup_early_printk(DEFAULT_EARLY_PORT); |
213 | ||
837ec2d5 RG |
214 | if (!shadow_console_enabled()) { |
215 | /* crap - we crashed before setup_arch() */ | |
216 | early_shadow_puts("panic before setup_arch\n"); | |
217 | early_shadow_puts("IPEND:"); | |
218 | early_shadow_reg(fp->ipend, 16); | |
219 | if (fp->seqstat & SEQSTAT_EXCAUSE) { | |
220 | early_shadow_puts("\nEXCAUSE:"); | |
221 | early_shadow_reg(fp->seqstat & SEQSTAT_EXCAUSE, 8); | |
222 | } | |
223 | if (fp->seqstat & SEQSTAT_HWERRCAUSE) { | |
224 | early_shadow_puts("\nHWERRCAUSE:"); | |
225 | early_shadow_reg( | |
226 | (fp->seqstat & SEQSTAT_HWERRCAUSE) >> 14, 8); | |
227 | } | |
228 | early_shadow_puts("\nErr @"); | |
229 | if (fp->ipend & EVT_EVX) | |
230 | early_shadow_reg(fp->retx, 32); | |
231 | else | |
232 | early_shadow_reg(fp->pc, 32); | |
233 | #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON | |
234 | early_shadow_puts("\nTrace:"); | |
235 | if (likely(bfin_read_TBUFSTAT() & TBUFCNT)) { | |
236 | while (bfin_read_TBUFSTAT() & TBUFCNT) { | |
237 | early_shadow_puts("\nT :"); | |
238 | early_shadow_reg(bfin_read_TBUF(), 32); | |
239 | early_shadow_puts("\n S :"); | |
240 | early_shadow_reg(bfin_read_TBUF(), 32); | |
241 | } | |
242 | } | |
243 | #endif | |
244 | early_shadow_puts("\nUse bfin-elf-addr2line to determine " | |
245 | "function names\n"); | |
246 | /* | |
247 | * We should panic(), but we can't - since panic calls printk, | |
248 | * and printk uses memcpy. | |
249 | * we want to reboot, but if the machine type is different, | |
250 | * can't due to machine specific reboot sequences | |
251 | */ | |
252 | if (CPUID == bfin_cpuid()) { | |
253 | early_shadow_puts("Trying to restart\n"); | |
254 | machine_restart(""); | |
255 | } | |
256 | ||
257 | early_shadow_puts("Halting, since it is not safe to restart\n"); | |
258 | while (1) | |
259 | asm volatile ("EMUEXCPT; IDLE;\n"); | |
260 | ||
261 | } else { | |
262 | printk(KERN_EMERG "Early panic\n"); | |
263 | show_regs(fp); | |
264 | dump_bfin_trace_buffer(); | |
265 | } | |
337d390b RG |
266 | |
267 | panic("Died early"); | |
268 | } | |
269 | ||
0ae53640 | 270 | early_param("earlyprintk", setup_early_printk); |