[block] Provide abstraction to allow system to be quiesced
When performing a SAN boot via INT 13, there is no way for the
operating system to indicate that it has finished using the INT 13 SAN
device. We therefore have no opportunity to clean up state before the
loaded operating system's native drivers take over. This can cause
problems when booting Windows, which tends not to be forgiving of
unexpected system state.
Windows will typically write a flag to the SAN device as the last
action before transferring control to the native drivers. We can use
this as a heuristic to bring the system to a quiescent state (without
performing a full shutdown); this provides us an opportunity to
temporarily clean up state that could otherwise prevent a successful
Windows boot.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[script] Allow for DOS-style line endings in scripts
Windows text editors such as Notepad tend to use CRLF line endings,
which breaks gPXE's signature detection for script images. Since
scripts are usually very small, they end up falling back to being
detected as valid PXE executable images (since there are no signature
checks for PXE executables). Executing text files as x86 machine code
tends not to work well.
Fix by allowing for any isspace() character to terminate the "#!gpxe"
signature, and by ensuring that CR characters get stripped during
command line parsing.
Suggested-by: Shao Miller <Shao.Miller@yrdsb.edu.on.ca>
Strip down i386 PCI configuration space I/O to the bare minimum. A
typical build will now include 880 bytes of PCI support code, compared to
2327 bytes in Etherboot 5.4.
(There is a slight cost of around 5 extra bytes per access to a
non-constant config space address; this should be an overall win.
Driver-specific accesses will usually be to constant addresses, for
which there is no additional cost.)
Michael Brown