--- wikisrc/users/jakllsch.mdwn	2009/10/21 23:23:09	1.2
+++ wikisrc/users/jakllsch.mdwn	2011/07/30 15:09:56	1.5
@@ -1,5 +1,28 @@
 # Jonathan Kollasch
 
+## [[!template id=man name="ddb" section="4"]] tips
+
+### locating a softc
+This locates a device's softc using it's `cfdriver_t` (e.g. `&mainbus_cd`, `&cpu_cd`) and its "device unit" (e.g. the `0` in `mainbus0`).
+
+    db{0}> call device_lookup_private(ohci_cd, 0)
+    0xffff800045fb2008
+
+### locating structure members
+This uses [[!template id=man name="gdb" section="1"]] and a kernel with debugging symbols to find the offset to a element in a structure.
+
+    $ gdb netbsd.gdb
+    ...
+    (gdb) print &((struct ohci_softc *)0)->iot
+    $3 = (bus_space_tag_t *) 0x478
+    (gdb) print &((struct ohci_softc *)0)->ioh
+    $4 = (bus_space_handle_t *) 0x480
+
+### peeking at mapped registers
+
+    db{0}> call bus_space_read_4(*(ffff800045fb2008+478), *(ffff800045fb2008+480), 0)
+    0x110
+
 ## Unfinished Projects
 
 ### x86 UEFI kernel loader
@@ -13,17 +36,5 @@ Boots multiuser on NFS root, needs more 
 This project is on hold until there's a miniature userland that fits in 4-8MiB flash storage devices, on a flash-oriented file system.
 [[!template id=man name="bce" section="4"]] and [[!template id=man name="bwi" section="4"]] would need refactoring to be bus-independent.
 
-### Conexant PCI DTV driver
-I have some code for 23880-3 and 887 host interfaces.
-This type of hardware is hard to find freely available docs for.
-Tuner/demod drivers from Linux could be ported, but would still be GPLed.
-Probably better to keep these drivers in userland.
-
-Should try to coordinate with what FreeBSD is doing: <http://wiki.freebsd.org/HDTV>.
-
 ### Memory-mapped PCI config access on x86
-Still need to figure out how pcitag_t will work for a 3rd mode that can't be switched on until after ACPI is initialized.
-Existing code I have assumes that no tags are generated until mmconf is turned on, which is not a reasonable assumption to make.
-
-## Possible Projects
-### AMD PowerNow/Cool'n'Quiet states loaded from ACPI tables
+Needs cleanup, and maybe some more validation of MCFG tables.