From: "Theodore A. Roth" <troth@openavr.org>
To: gdb-patches@sources.redhat.com
Subject: [commit] [avr] prologue scanner update
Date: Mon, 16 Jun 2003 00:44:00 -0000 [thread overview]
Message-ID: <Pine.LNX.4.44.0306151740230.20396-200000@bozoland.mynet> (raw)
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Hi,
Committed the attached.
This updates the avr prologue scanner and fixes a few problems.
Ted Roth
2003-06-15 Theodore A. Roth <troth@openavr.org>
* avr-tdep.c (avr_scan_prologue): Update comment describing the various
prologue types.
Properly scan prologues generated by gcc with the -mcall-prologues
option.
Add code to scan -mcall-prologues for mega devices.
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2003-06-15 Theodore A. Roth <troth@openavr.org>
* ChangeLog:
* avr-tdep.c:
Index: ChangeLog
===================================================================
RCS file: /cvs/src/src/gdb/ChangeLog,v
retrieving revision 1.4395
diff -u -p -r1.4395 ChangeLog
--- ChangeLog 15 Jun 2003 22:01:05 -0000 1.4395
+++ ChangeLog 16 Jun 2003 00:34:27 -0000
@@ -1,5 +1,13 @@
2003-06-15 Theodore A. Roth <troth@openavr.org>
+ * avr-tdep.c (avr_scan_prologue): Update comment describing the various
+ prologue types.
+ Properly scan prologues generated by gcc with the -mcall-prologues
+ option.
+ Add code to scan -mcall-prologues for mega devices.
+
+2003-06-15 Theodore A. Roth <troth@openavr.org>
+
* avr-tdep.c (avr_register_byte): Delete function.
(avr_register_raw_size): Delete function.
(avr_register_virtual_size): Delete function.
Index: avr-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/avr-tdep.c,v
retrieving revision 1.57
diff -u -p -r1.57 avr-tdep.c
--- avr-tdep.c 15 Jun 2003 22:01:05 -0000 1.57
+++ avr-tdep.c 16 Jun 2003 00:34:34 -0000
@@ -359,26 +359,81 @@ avr_read_fp (void)
3) the offsets of saved regs
This information is stored in the "extra_info" field of the frame_info.
- A typical AVR function prologue might look like this:
- push rXX
- push r28
- push r29
- in r28,__SP_L__
- in r29,__SP_H__
- sbiw r28,<LOCALS_SIZE>
- in __tmp_reg__,__SREG__
+ Some devices lack the sbiw instruction, so on those replace this:
+ sbiw r28, XX
+ with this:
+ subi r28,lo8(XX)
+ sbci r29,hi8(XX)
+
+ A typical AVR function prologue with a frame pointer might look like this:
+ push rXX ; saved regs
+ ...
+ push r28
+ push r29
+ in r28,__SP_L__
+ in r29,__SP_H__
+ sbiw r28,<LOCALS_SIZE>
+ in __tmp_reg__,__SREG__
cli
- out __SP_L__,r28
- out __SREG__,__tmp_reg__
- out __SP_H__,r29
-
- A `-mcall-prologues' prologue look like this:
- ldi r26,<LOCALS_SIZE>
- ldi r27,<LOCALS_SIZE>/265
- ldi r30,pm_lo8(.L_foo_body)
- ldi r31,pm_hi8(.L_foo_body)
- rjmp __prologue_saves__+RRR
- .L_foo_body: */
+ out __SP_L__,r28
+ out __SREG__,__tmp_reg__
+ out __SP_H__,r29
+
+ A typical AVR function prologue without a frame pointer might look like
+ this:
+ push rXX ; saved regs
+ ...
+
+ A main function prologue looks like this:
+ ldi r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>)
+ ldi r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>)
+ out __SP_H__,r29
+ out __SP_L__,r28
+
+ A signal handler prologue looks like this:
+ push __zero_reg__
+ push __tmp_reg__
+ in __tmp_reg__, __SREG__
+ push __tmp_reg__
+ clr __zero_reg__
+ push rXX ; save registers r18:r27, r30:r31
+ ...
+ push r28 ; save frame pointer
+ push r29
+ in r28, __SP_L__
+ in r29, __SP_H__
+ sbiw r28, <LOCALS_SIZE>
+ out __SP_H__, r29
+ out __SP_L__, r28
+
+ A interrupt handler prologue looks like this:
+ sei
+ push __zero_reg__
+ push __tmp_reg__
+ in __tmp_reg__, __SREG__
+ push __tmp_reg__
+ clr __zero_reg__
+ push rXX ; save registers r18:r27, r30:r31
+ ...
+ push r28 ; save frame pointer
+ push r29
+ in r28, __SP_L__
+ in r29, __SP_H__
+ sbiw r28, <LOCALS_SIZE>
+ cli
+ out __SP_H__, r29
+ sei
+ out __SP_L__, r28
+
+ A `-mcall-prologues' prologue looks like this (Note that the megas use a
+ jmp instead of a rjmp, thus the prologue is one word larger since jmp is a
+ 32 bit insn and rjmp is a 16 bit insn):
+ ldi r26,lo8(<LOCALS_SIZE>)
+ ldi r27,hi8(<LOCALS_SIZE>)
+ ldi r30,pm_lo8(.L_foo_body)
+ ldi r31,pm_hi8(.L_foo_body)
+ rjmp __prologue_saves__+RRR
+ .L_foo_body: */
static void
avr_scan_prologue (struct frame_info *fi)
@@ -457,10 +512,9 @@ avr_scan_prologue (struct frame_info *fi
}
}
- /* Scanning `-mcall-prologues' prologue
- FIXME: mega prologue have a 12 bytes long */
+ /* Scanning `-mcall-prologues' prologue */
- while (prologue_len <= 12) /* I'm use while to avoit many goto's */
+ while (1) /* Using a while to avoid many goto's */
{
int loc_size;
int body_addr;
@@ -490,9 +544,6 @@ avr_scan_prologue (struct frame_info *fi
break;
body_addr |= ((insn & 0xf) | ((insn & 0x0f00) >> 4)) << 8;
- if (body_addr != (prologue_start + 10) / 2)
- break;
-
msymbol = lookup_minimal_symbol ("__prologue_saves__", NULL, NULL);
if (!msymbol)
break;
@@ -500,15 +551,33 @@ avr_scan_prologue (struct frame_info *fi
/* FIXME: prologue for mega have a JMP instead of RJMP */
insn = EXTRACT_INSN (&prologue[vpc + 8]);
/* rjmp __prologue_saves__+RRR */
- if ((insn & 0xf000) != 0xc000)
- break;
+ if ((insn & 0xf000) == 0xc000)
+ {
+ /* Extract PC relative offset from RJMP */
+ i = (insn & 0xfff) | (insn & 0x800 ? (-1 ^ 0xfff) : 0);
+ /* Convert offset to byte addressable mode */
+ i *= 2;
+ /* Destination address */
+ i += prologue_start + 10;
+
+ if (body_addr != (prologue_start + 10) / 2)
+ break;
+ }
+ /* jmp __prologue_saves__+RRR */
+ else if ((insn & 0xfe0e) == 0x940c)
+ {
+ /* Extract absolute PC address from JMP */
+ i = (((insn & 0x1) | ((insn & 0x1f0) >> 3) << 16)
+ | (EXTRACT_INSN (&prologue[vpc + 10]) & 0xffff));
+ /* Convert address to byte addressable mode */
+ i *= 2;
+
+ if (body_addr != (prologue_start + 12)/2)
+ break;
+ }
+ else
+ break;
- /* Extract PC relative offset from RJMP */
- i = (insn & 0xfff) | (insn & 0x800 ? (-1 ^ 0xfff) : 0);
- /* Convert offset to byte addressable mode */
- i *= 2;
- /* Destination address */
- i += vpc + prologue_start + 10;
/* Resovle offset (in words) from __prologue_saves__ symbol.
Which is a pushes count in `-mcall-prologues' mode */
num_pushes = AVR_MAX_PUSHES - (i - SYMBOL_VALUE_ADDRESS (msymbol)) / 2;
@@ -606,9 +675,9 @@ avr_scan_prologue (struct frame_info *fi
sbci r29,hi8(XX)
in __tmp_reg__,__SREG__
cli
- out __SP_L__,r28
+ out __SP_H__,r29
out __SREG__,__tmp_reg__
- out __SP_H__,r29 */
+ out __SP_L__,r28 */
if (scan_stage == 2 && vpc + 12 <= prologue_len)
{
@@ -616,19 +685,19 @@ avr_scan_prologue (struct frame_info *fi
unsigned char img[] = {
0x0f, 0xb6, /* in r0,0x3f */
0xf8, 0x94, /* cli */
- 0xcd, 0xbf, /* out 0x3d,r28 ; SPL */
+ 0xde, 0xbf, /* out 0x3e,r29 ; SPH */
0x0f, 0xbe, /* out 0x3f,r0 ; SREG */
- 0xde, 0xbf /* out 0x3e,r29 ; SPH */
+ 0xcd, 0xbf /* out 0x3d,r28 ; SPL */
};
unsigned char img_sig[] = {
- 0xcd, 0xbf, /* out 0x3d,r28 ; SPL */
- 0xde, 0xbf /* out 0x3e,r29 ; SPH */
+ 0xde, 0xbf, /* out 0x3e,r29 ; SPH */
+ 0xcd, 0xbf /* out 0x3d,r28 ; SPL */
};
unsigned char img_int[] = {
0xf8, 0x94, /* cli */
- 0xcd, 0xbf, /* out 0x3d,r28 ; SPL */
+ 0xde, 0xbf, /* out 0x3e,r29 ; SPH */
0x78, 0x94, /* sei */
- 0xde, 0xbf /* out 0x3e,r29 ; SPH */
+ 0xcd, 0xbf /* out 0x3d,r28 ; SPL */
};
insn = EXTRACT_INSN (&prologue[vpc]);
reply other threads:[~2003-06-16 0:44 UTC|newest]
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