The makefile can be adjusted to make a version of adb for nonseparate I/D machines. Change the -DNUM_VM_PAGES value to something like 6 to 8, this will use less real memory (and cause adb to run a bit slower) and allow adb to run on a non-split I/D machine. Changes for overlaid processes are intended to work in the most obvious way and are: 1. There is an additional map for an overlay (430 or 431) object file, described by the triple (bo,eo,fo). bo is initialized on startup, and the others are changed on setting an overlay. This is done automatically if there is an appropriate corefile or when a traced subprocess stops, and can be done manually (described below). 2. There are two additional internal variables set for overlay objects. The variable o is the sum of the overlay sizes. c is the current overlay number. It is set automatically as described above, and can be changed manually (#>c). This changes the overlay map (eo and fo) to map in the named overlay. This affects only adb's mapping. 3. Although the variable c controls the overlay map, the "register" variable "ov" reflects the overlay actually mapped when the process stopped (or dumped core). This value is shown as "ov" in the register list ($r). It may also be used as other register variables, in the "<" and ">" commands. In the latter case, this actually causes the kernel to remap the subprocess, and the correct overlay must be mapped to restart the process. NOTE: the kernel routine procxmt must support overlay changes for this to work. The (1982) 2bsd distribution includes the necessary changes. 4. For text symbols in overlaid objects, the default symbol used to find "name" is "~name" rather than "_name". This means that the actual subroutine, rather than its thunk, is found. To examine a thunk, use "_name" explicitly. 5. In the overlaid segment, only symbols in the current overlay (c) are used in symbolic addresses. In order to find these overlay numbers, the new version of (ov)ld must be used. The reason for this is that the previous version of ovld put the overlay number only in symbols for thunks, not in local text symbols. 6. In order to support breakpoints in overlaid segments, the strategy used by adb has been changed slightly. Breakpoints are written into the subprocess immediately when a ":b" command is executed, and deleted immediately with ":d". Changes to support overlaid kernels: 1. The user's saved registers are in different places in the kernel stack. They are found relative to the entry u.u_ar0 in the core file if there is one, with offsets from and . If there is no core file,a default is used. This default is defined as UAR0 in defs.h. ******* UAR0 should be checked whenever the user structure changes. 2. There is a new command-line flag, -k, which sets things appropriately for the kernel. It sets the mapping of the core file appropriately for 407, 411 and 430 kernels, and changes the debugger's idea of saved register locations. Thus, $r will print the register values saved by dump, and $c will use the saved r5 from low core. In addition, a number of minor bugs have been fixed. Mike Karels ucbvax!virus!mike Department of Molecular Biology University of California, Berkeley