From: Julian Stecklina <julian.stecklina@xxxxxxxxxxxxxxxxxxxxx>
Add erofs detection to the initrd mount code. This allows systems to
boot from an erofs-based initrd in the same way as they can boot from
a squashfs initrd.
Just as squashfs initrds, erofs images as initrds are a good option
for systems that are memory-constrained.
Signed-off-by: Julian Stecklina <julian.stecklina@xxxxxxxxxxxxxxxxxxxxx>
---
init/do_mounts_rd.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c
index ac021ae6e6fa78c7b7828a78ab2fa3af3611bef3..7c3f8b45b5ed2eea3c534d7f2e65608542009df5 100644
--- a/init/do_mounts_rd.c
+++ b/init/do_mounts_rd.c
@@ -11,6 +11,7 @@
#include "do_mounts.h"
#include "../fs/squashfs/squashfs_fs.h"
+#include "../fs/erofs/erofs_fs.h"
#include <linux/decompress/generic.h>
@@ -47,6 +48,7 @@ static int __init crd_load(decompress_fn deco);
* romfs
* cramfs
* squashfs
+ * erofs
* gzip
* bzip2
* lzma
@@ -63,6 +65,7 @@ identify_ramdisk_image(struct file *file, loff_t pos,
struct romfs_super_block *romfsb;
struct cramfs_super *cramfsb;
struct squashfs_super_block *squashfsb;
+ struct erofs_super_block *erofsb;
int nblocks = -1;
unsigned char *buf;
const char *compress_name;
@@ -77,6 +80,7 @@ identify_ramdisk_image(struct file *file, loff_t pos,
romfsb = (struct romfs_super_block *) buf;
cramfsb = (struct cramfs_super *) buf;
squashfsb = (struct squashfs_super_block *) buf;
+ erofsb = (struct erofs_super_block *) buf;
memset(buf, 0xe5, size);
/*
@@ -165,6 +169,21 @@ identify_ramdisk_image(struct file *file, loff_t pos,
goto done;
}
+ /* Try erofs */
+ pos = (start_block * BLOCK_SIZE) + EROFS_SUPER_OFFSET;
+ kernel_read(file, buf, size, &pos);
+
+ if (erofsb->magic == EROFS_SUPER_MAGIC_V1) {
+ printk(KERN_NOTICE
+ "RAMDISK: erofs filesystem found at block %d\n",
+ start_block);
+
+ nblocks = ((erofsb->blocks << erofsb->blkszbits) + BLOCK_SIZE - 1)
+ >> BLOCK_SIZE_BITS;
+
+ goto done;
+ }
+
printk(KERN_NOTICE
"RAMDISK: Couldn't find valid RAM disk image starting at %d.\n",
start_block);
---
base-commit: 5fc31936081919a8572a3d644f3fbb258038f337
change-id: 20250320-initrd-erofs-76e925fdf68c
Best regards,
--
Julian Stecklina <julian.stecklina@xxxxxxxxxxxxxxxxxxxxx>
