Multi-level menus via COMBOOT rely on the COMBOOT program being able
to exit and invoke a new COMBOOT program (the next menu). This works,
but rapidly (within about five iterations) runs out of space in gPXE's
internal stack, since each new image is executed in a new function
context.
Fix by allowing tail recursion between images; an image can now
specify a replacement image for itself, and image_exec() will perform
the necessary tail recursion.
Clearing the LOADED flag actually prevents users from doing clever things
such as loading an image, then loading a patch image, then executing the
first image. (image_exec() checks for IMAGE_LOADED, so this sequence of
operations will fail if the LOADED flag gets cleared.)
This reverts commit 14c080020f.
Loading an image may overwrite part or all of any previously-loaded
images, so we should clear the LOADED flag for all images prior to
attempting to load a new image.
took out the contract to eventually call efree() when it called fetch().
Maintain the most recently loaded image at the start of the list, so that
imgautoselect() will pick it.
refer to them by name from the command line, or build them into a
multiboot module list.
Use setting image->type to disambiguate between "not my image" and "bad
image"; this avoids relying on specific values of the error code.
for use by malloc().
This breaks the image-loading code (which previously used the heap to
allocate the buffer for downloading the image), but that's not a major
concern since I'm going to tear out all the image formats within the next
couple of days anyway. Byebye, NBI! :)
Michael Brown