1 #include <common.h>
2 #include <command.h>
3 #include <kgdb.h>
4 #include <asm/signal.h>
5 #include <asm/processor.h>
6
7 #define PC_REGNUM 64
8 #define SP_REGNUM 1
9
10 void breakinst(void);
11
12 int
kgdb_setjmp(long * buf)13 kgdb_setjmp(long *buf)
14 {
15 unsigned long temp;
16
17 asm volatile("mflr %0; stw %0,0(%1);"
18 "stw %%r1,4(%1); stw %%r2,8(%1);"
19 "mfcr %0; stw %0,12(%1);"
20 "stmw %%r13,16(%1)"
21 : "=&r"(temp) : "r" (buf));
22 /* XXX should save fp regs as well */
23 return 0;
24 }
25
26 void
kgdb_longjmp(long * buf,int val)27 kgdb_longjmp(long *buf, int val)
28 {
29 unsigned long temp;
30
31 if (val == 0)
32 val = 1;
33
34 asm volatile("lmw %%r13,16(%1);"
35 "lwz %0,12(%1); mtcrf 0x38,%0;"
36 "lwz %0,0(%1); lwz %%r1,4(%1); lwz %%r2,8(%1);"
37 "mtlr %0; mr %%r3,%2"
38 : "=&r"(temp) : "r" (buf), "r" (val));
39 }
40
41 /* Convert the SPARC hardware trap type code to a unix signal number. */
42 /*
43 * This table contains the mapping between PowerPC hardware trap types, and
44 * signals, which are primarily what GDB understands.
45 */
46 static struct hard_trap_info
47 {
48 unsigned int tt; /* Trap type code for powerpc */
49 unsigned char signo; /* Signal that we map this trap into */
50 } hard_trap_info[] = {
51 { 0x200, SIGSEGV }, /* machine check */
52 { 0x300, SIGSEGV }, /* address error (store) */
53 { 0x400, SIGBUS }, /* instruction bus error */
54 { 0x500, SIGINT }, /* interrupt */
55 { 0x600, SIGBUS }, /* alignment */
56 { 0x700, SIGTRAP }, /* breakpoint trap */
57 { 0x800, SIGFPE }, /* fpu unavail */
58 { 0x900, SIGALRM }, /* decrementer */
59 { 0xa00, SIGILL }, /* reserved */
60 { 0xb00, SIGILL }, /* reserved */
61 { 0xc00, SIGCHLD }, /* syscall */
62 { 0xd00, SIGTRAP }, /* single-step/watch */
63 { 0xe00, SIGFPE }, /* fp assist */
64 { 0, 0} /* Must be last */
65 };
66
67 static int
computeSignal(unsigned int tt)68 computeSignal(unsigned int tt)
69 {
70 struct hard_trap_info *ht;
71
72 for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
73 if (ht->tt == tt)
74 return ht->signo;
75
76 return SIGHUP; /* default for things we don't know about */
77 }
78
79 void
kgdb_enter(struct pt_regs * regs,kgdb_data * kdp)80 kgdb_enter(struct pt_regs *regs, kgdb_data *kdp)
81 {
82 unsigned long msr;
83
84 kdp->private[0] = msr = get_msr();
85 set_msr(msr & ~MSR_EE); /* disable interrupts */
86
87 if (regs->nip == (unsigned long)breakinst) {
88 /* Skip over breakpoint trap insn */
89 regs->nip += 4;
90 }
91 regs->msr &= ~MSR_SE;
92
93 /* reply to host that an exception has occurred */
94 kdp->sigval = computeSignal(regs->trap);
95
96 kdp->nregs = 2;
97
98 kdp->regs[0].num = PC_REGNUM;
99 kdp->regs[0].val = regs->nip;
100
101 kdp->regs[1].num = SP_REGNUM;
102 kdp->regs[1].val = regs->gpr[SP_REGNUM];
103 }
104
105 void
kgdb_exit(struct pt_regs * regs,kgdb_data * kdp)106 kgdb_exit(struct pt_regs *regs, kgdb_data *kdp)
107 {
108 unsigned long msr = kdp->private[0];
109
110 if (kdp->extype & KGDBEXIT_WITHADDR)
111 regs->nip = kdp->exaddr;
112
113 switch (kdp->extype & KGDBEXIT_TYPEMASK) {
114
115 case KGDBEXIT_KILL:
116 case KGDBEXIT_CONTINUE:
117 set_msr(msr);
118 break;
119
120 case KGDBEXIT_SINGLE:
121 regs->msr |= MSR_SE;
122 #if 0
123 set_msr(msr | MSR_SE);
124 #endif
125 break;
126 }
127 }
128
129 int
kgdb_trap(struct pt_regs * regs)130 kgdb_trap(struct pt_regs *regs)
131 {
132 return (regs->trap);
133 }
134
135 /* return the value of the CPU registers.
136 * some of them are non-PowerPC names :(
137 * they are stored in gdb like:
138 * struct {
139 * u32 gpr[32];
140 * f64 fpr[32];
141 * u32 pc, ps, cnd, lr; (ps=msr)
142 * u32 cnt, xer, mq;
143 * }
144 */
145
146 #define SPACE_REQUIRED ((32*4)+(32*8)+(6*4))
147
148 int
kgdb_getregs(struct pt_regs * regs,char * buf,int max)149 kgdb_getregs(struct pt_regs *regs, char *buf, int max)
150 {
151 int i;
152 unsigned long *ptr = (unsigned long *)buf;
153
154 if (max < SPACE_REQUIRED)
155 kgdb_error(KGDBERR_NOSPACE);
156
157 if ((unsigned long)ptr & 3)
158 kgdb_error(KGDBERR_ALIGNFAULT);
159
160 /* General Purpose Regs */
161 for (i = 0; i < 32; i++)
162 *ptr++ = regs->gpr[i];
163
164 /* Floating Point Regs */
165 for (i = 0; i < 32; i++) {
166 *ptr++ = 0;
167 *ptr++ = 0;
168 }
169
170 /* pc, msr, cr, lr, ctr, xer, (mq is unused) */
171 *ptr++ = regs->nip;
172 *ptr++ = regs->msr;
173 *ptr++ = regs->ccr;
174 *ptr++ = regs->link;
175 *ptr++ = regs->ctr;
176 *ptr++ = regs->xer;
177
178 return (SPACE_REQUIRED);
179 }
180
181 /* set the value of the CPU registers */
182 void
kgdb_putreg(struct pt_regs * regs,int regno,char * buf,int length)183 kgdb_putreg(struct pt_regs *regs, int regno, char *buf, int length)
184 {
185 unsigned long *ptr = (unsigned long *)buf;
186
187 if (regno < 0 || regno >= 70)
188 kgdb_error(KGDBERR_BADPARAMS);
189 else if (regno >= 32 && regno < 64) {
190 if (length < 8)
191 kgdb_error(KGDBERR_NOSPACE);
192 }
193 else {
194 if (length < 4)
195 kgdb_error(KGDBERR_NOSPACE);
196 }
197
198 if ((unsigned long)ptr & 3)
199 kgdb_error(KGDBERR_ALIGNFAULT);
200
201 if (regno >= 0 && regno < 32)
202 regs->gpr[regno] = *ptr;
203 else switch (regno) {
204 case 64: regs->nip = *ptr; break;
205 case 65: regs->msr = *ptr; break;
206 case 66: regs->ccr = *ptr; break;
207 case 67: regs->link = *ptr; break;
208 case 68: regs->ctr = *ptr; break;
209 case 69: regs->ctr = *ptr; break;
210
211 default:
212 kgdb_error(KGDBERR_BADPARAMS);
213 }
214 }
215
216 void
kgdb_putregs(struct pt_regs * regs,char * buf,int length)217 kgdb_putregs(struct pt_regs *regs, char *buf, int length)
218 {
219 int i;
220 unsigned long *ptr = (unsigned long *)buf;
221
222 if (length < SPACE_REQUIRED)
223 kgdb_error(KGDBERR_NOSPACE);
224
225 if ((unsigned long)ptr & 3)
226 kgdb_error(KGDBERR_ALIGNFAULT);
227
228 /*
229 * If the stack pointer has moved, you should pray.
230 * (cause only god can help you).
231 */
232
233 /* General Purpose Regs */
234 for (i = 0; i < 32; i++)
235 regs->gpr[i] = *ptr++;
236
237 /* Floating Point Regs */
238 ptr += 32*2;
239
240 /* pc, msr, cr, lr, ctr, xer, (mq is unused) */
241 regs->nip = *ptr++;
242 regs->msr = *ptr++;
243 regs->ccr = *ptr++;
244 regs->link = *ptr++;
245 regs->ctr = *ptr++;
246 regs->xer = *ptr++;
247 }
248
249 /* This function will generate a breakpoint exception. It is used at the
250 beginning of a program to sync up with a debugger and can be used
251 otherwise as a quick means to stop program execution and "break" into
252 the debugger. */
253
254 void
kgdb_breakpoint(int argc,char * const argv[])255 kgdb_breakpoint(int argc, char * const argv[])
256 {
257 asm(" .globl breakinst\n\
258 breakinst: .long 0x7d821008\n\
259 ");
260 }
261