diff options
Diffstat (limited to 'gitlab/issues_text/target_m68k/host_missing/accel_missing/2483')
| -rw-r--r-- | gitlab/issues_text/target_m68k/host_missing/accel_missing/2483 | 20 |
1 files changed, 0 insertions, 20 deletions
diff --git a/gitlab/issues_text/target_m68k/host_missing/accel_missing/2483 b/gitlab/issues_text/target_m68k/host_missing/accel_missing/2483 deleted file mode 100644 index df22f6afa..000000000 --- a/gitlab/issues_text/target_m68k/host_missing/accel_missing/2483 +++ /dev/null @@ -1,20 +0,0 @@ -m68k: jsr (sp) doesn't work as expected -Description of problem: -Consider the following code (disassembly from ghidra). This copies the current `SP` to `A1` then copies 0x68 bytes from the address pointed at by `A0` to the address pointed at by `A1` with increment. This should end up with a copy of some bytes and `SP` pointing at the first. - -``` - ff8241e6 22 4f movea.l SP,A1 - ff8241e8 70 68 moveq #0x68,D0 - LAB_ff8241ea XREF[1]: ff8241ee(j) - ff8241ea 12 d8 move.b (A0)+,(A1)+ - ff8241ec 53 80 subq.l #0x1,D0 - ff8241ee 66 fa bne.b LAB_ff8241ea - ff8241f0 4e 97 jsr (SP) -``` - -`SP` is `0x3bfc` at the `jsr` so we'd expect to jump to `0x3bfc` and put the address to return to at `0x3bf8` so the `jsr` can return I think? -What currently happens in QEMU is the return address is put at `0xb3f8` and `PC` also becomes `0x3bf8` and the return address starts being executed as code and things go off the rails. - -Forgive the screenshot but this is what it looks like with GDB connected. Dumping the memory where the `PC` is shows that the return address is actually there and we can see there is garbage before the instructions it should be executing. - -{width=289 height=759} |