david/ipxe
david
/
ipxe
Archived
1
0
Fork 0
Code

[GDB] Zero-extend 16-bit segment registers 

When the 16-bit segment registers are accessed using 32-bit instructions
the high order bytes are undefined on older CPUs.  We now explicitly
zero the high order bytes when snapshotting the CPU state.  This ensures
that the GDB stub reports consistent values for the segment registers.
This commit is contained in:
Stefan Hajnoczi 2008-06-13 10:26:49 +01:00 committed by Michael Brown
parent 5504fa9047
commit 3715c8c721
2 changed files with 14 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
src/arch/i386/core/gdbidt.S
View File

@ -163,12 +163,18 @@ int_page_fault:
#define IH_OFFSET_FLUX_END ( IH_OFFSET_END - 20 )
do_interrupt:
/* Store CPU state in GDB register snapshot */
pushl %gs
pushl %fs
pushl %es
pushl %ds
pushl %ss
pushl IH_OFFSET_FLUX_OLD_CS(%esp)
pushw $0
pushw %gs
pushw $0
pushw %fs
pushw $0
pushw %es
pushw $0
pushw %ds
pushw $0
pushw %ss
pushw $0
pushw IH_OFFSET_FLUX_OLD_CS + 2(%esp)
pushl IH_OFFSET_FLUX_OLD_EFLAGS(%esp)
pushl IH_OFFSET_FLUX_OLD_EIP(%esp)
pushl %edi

4
src/tests/gdbstub_test.gdb
View File

@ -81,13 +81,13 @@ define gpxe_test_awatch
awatch watch_me
c
gpxe_assert $ecx 0x600d0000 "gpxe_test_awatch"
gpxe_assert $ecx 0x600d0000 "gpxe_test_awatch read"
if $ecx == 0x600d0000
c
end
c
gpxe_assert $ecx 0x600d0001 "gpxe_test_awatch"
gpxe_assert $ecx 0x600d0001 "gpxe_test_awatch write"
if $ecx == 0x600d0001
c
end