misc: Converge with 5.x

PHILOSOPHY.md

@@ -21,6 +21,10 @@ way to modify its own EFI executable to bake in the BLAKE2B checksum of the conf
 a key added to the firmware's keychain. This prevents modifications to the config file (and in turn the checksums contained there)
 from going unnoticed.
 
+### What about ext2/3/4? Why is that supported then?
+
+This is explicitly against the philosophy, but it is a pragmatic compromise since a lot of Linux distros and setups expect it to "work that way".
+
 ### But I don't want to have a separate FAT boot partition! I don't want it!!!
 
 Well tough luck. It is `$year_following_2012` now and most PCs are equipped with UEFI and simply won't boot without a FAT EFI system partition

README.md

@@ -38,6 +38,7 @@ Donations welcome, but absolutely not mandatory!
 * Unpartitioned media
 
 ### Supported filesystems
+* ext2/3/4
 * FAT12/16/32
 * ISO9660 (CDs/DVDs)
 

common/fs/ext2.h

@@ -0,0 +1,13 @@
+#ifndef __FS__EXT2_H__
+#define __FS__EXT2_H__
+
+#include <stdbool.h>
+#include <lib/part.h>
+#include <fs/file.h>
+
+bool ext2_get_guid(struct guid *guid, struct volume *part);
+char *ext2_get_label(struct volume *part);
+
+struct file_handle *ext2_open(struct volume *part, const char *path);
+
+#endif