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authorDon Dugger <n0ano@n0ano.com>2016-06-03 03:33:22 +0000
committerGerrit Code Review <gerrit@172.30.200.206>2016-06-03 03:33:23 +0000
commitda27230f80795d0028333713f036d44c53cb0e68 (patch)
treeb3d379eaf000adf72b36cb01cdf4d79c3e3f064c /qemu/roms/seabios/docs/Debugging.md
parent0e68cb048bb8aadb14675f5d4286d8ab2fc35449 (diff)
parent437fd90c0250dee670290f9b714253671a990160 (diff)
Merge "These changes are the raw update to qemu-2.6."
Diffstat (limited to 'qemu/roms/seabios/docs/Debugging.md')
-rw-r--r--qemu/roms/seabios/docs/Debugging.md27
1 files changed, 16 insertions, 11 deletions
diff --git a/qemu/roms/seabios/docs/Debugging.md b/qemu/roms/seabios/docs/Debugging.md
index 03567de4d..7ab5d02d8 100644
--- a/qemu/roms/seabios/docs/Debugging.md
+++ b/qemu/roms/seabios/docs/Debugging.md
@@ -55,8 +55,10 @@ rate.
The tool can also timestamp the messages from the QEMU debug port. To
use with QEMU run the following:
-`mkfifo qemudebugpipe`\
-`qemu -chardev pipe,path=qemudebugpipe,id=seabios -device isa-debugcon,iobase=0x402,chardev=seabios ...`
+```
+mkfifo qemudebugpipe
+qemu -chardev pipe,path=qemudebugpipe,id=seabios -device isa-debugcon,iobase=0x402,chardev=seabios ...
+```
and then in another session:
@@ -84,20 +86,23 @@ bios 16bit code) or out/rom.o (to debug bios 32bit code). For example:
`gdb out/rom16.o`
-Once in gdb, use the command "target remote localhost:1234" to have
+Once in gdb, use the command `target remote localhost:1234` to have
gdb connect to QEMU. See the QEMU documentation for more information
on using gdb and QEMU in this mode.
-When debugging 16bit code, also run the following commands in gdb:
+When debugging 16bit code it is necessary to load the 16bit symbols
+twice in order for gdb to properly handle break points. To do this,
+run the following command `objcopy --adjust-vma 0xf0000 out/rom16.o
+rom16offset.o` and then run the following in gdb:
-`set architecture i8086`\
-`add-symbol-file out/rom16.o 0xf0000`
+```
+set architecture i8086
+add-symbol-file rom16offset.o 0
+```
-The second command loads the 16bit symbols a second time at an offset
-of 0xf0000, which helps gdb set and catch breakpoints correctly.
-
-To debug a VGA BIOS image, run "gdb out/vgarom.o" add use the gdb
-command "add-symbol-file out/vgarom.o 0xc0000" to load the 16bit VGA
+To debug a VGA BIOS image, run `gdb out/vgarom.o`, create a
+vgaromoffset.o file with offset 0xc0000, add use the gdb
+command `add-symbol-file out/vgaromoffset.o 0` to load the 16bit VGA
BIOS symbols twice.
If debugging the 32bit SeaBIOS initialization code with gdb, note that