Update the documentation with regards to the new IPF code

doc/authors.txt

@@ -241,3 +241,6 @@ projects which we would like to acknowledge here:
 - The MMU emulation for the 68030 has been taken from the NeXT emulator
   Previous (thanks to Andreas Grabher!). Since Hatari 1.9, this is now
   taken from WinUAE which uses the same code base.
+
+- The internal IPF disk support uses code from the IPF decoder from MAME,
+  originally written by Olivier Galibert.

doc/release-notes.txt

@@ -41,6 +41,11 @@ Build / dependency changes:
 - More fine-grained build debug options
 
 Emulation improvements:
+- Floppy disks:
+  - Built-in support for IPF images (based on the decoder code from MAME).
+    There is no support for CTR images, and the code might have problems
+    with certain disk images, i.e. it is recommended to still use the
+    original capslib in case of problems.
 
 Emulator improvements:
 - CLI options:

readme.txt

@@ -86,7 +86,8 @@ Optional:
 - The PortMidi library required for MIDI device support on macOS and Windows
   (http://portmedia.sourceforge.net/)
 - The udev library for NatFeats SCSI driver media change detection
-- The IPF support library (http://www.softpres.org/download)
+- The IPF support library
+  (http://www.softpres.org/download & https://www.kryoflux.com/?page=download)
 - The Capstone library (version >= 4.0) for traditional disassembly output
   in the debugger (https://www.capstone-engine.org/)
 
@@ -158,6 +159,8 @@ webserver for testing it locally.
 
  3.3) IPF support using capsimage library
 
+While Hatari has built-in support for IPF images, the related code is
+still experimental and cannot load all types of IPF images. Thus
 Hatari can use the optional capsimage library to access IPF and CTR
 files. Those files are created using the Kryoflux board and allow to
 record MFM exact copies of original games, including the protection.
@@ -165,8 +168,9 @@ record MFM exact copies of original games, including the protection.
 Hatari supports version 5.1 of the library (previous support for older
 version 4.2 was removed as it is not used anymore)
 
-Refer to http://softpres.org/download and get the corresponding file
-from the "User Distribution" section that matches your OS.
+Refer to the "User Distribution" section on http://softpres.org/download or
+the "SPS Decoder Library" section on https://www.kryoflux.com/?page=download
+and get the corresponding file that matches your OS.
 
 For version 5.1, you should have the following files in your include path :
 /usr/local/include/caps/

src/floppies/ipf_dsk.c

@@ -1,5 +1,13 @@
-// license:BSD-3-Clause
-// copyright-holders:Olivier Galibert
+/*
+ * IPF (Interchangeable Preservation Format) disk image support.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ * Original copyright by: Olivier Galibert (from MAME project)
+ *
+ * IPF files are decoded natively into per-track flux transition lists, then
+ * processed by Hatari's WD1772 FDC through the shared mfm_stream flux path
+ * (same approach as SCP / Kryoflux streams).
+ */
 
 #include <string.h>
 #include <errno.h>

src/includes/floppy.h

@@ -23,7 +23,7 @@
 #define	FLOPPY_IMAGE_TYPE_ST			1
 #define	FLOPPY_IMAGE_TYPE_MSA			2
 #define	FLOPPY_IMAGE_TYPE_DIM			3
-#define	FLOPPY_IMAGE_TYPE_IPF			4		/* handled by capsimage library */
+#define	FLOPPY_IMAGE_TYPE_IPF			4
 #define	FLOPPY_IMAGE_TYPE_STX			5
 #define	FLOPPY_IMAGE_TYPE_SCP			6
 #define	FLOPPY_IMAGE_TYPE_KFS			7		/* Kryoflux stream raw */