From: Pragnesh Sampat The file initramfs_data.cpio is slightly different when generated on cygwin, compared to linux, which causes the kernel to panic with the message "no cpio magic" (See Documentation/early-userspace/README). The problem in cpio generation is due to the difference in sprintf modifiers on cygwin. The code uses "%08ZX" for strlen of a device node. printf man pages discourages "Z" and has 'z' instead. Both of these are not available on cygwin sprintf (at least some versions of cygwin). The net result of all of this is that the generated file literally contains "ZX" and then the strlen after that and messes up that 110 offset etc. The file is 516 bytes long on the system that I tested and on linux it is 512 bytes. The fix below just uses "%08X" for that field. --- 25-akpm/usr/gen_init_cpio.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-) diff -puN usr/gen_init_cpio.c~cygwin-cpio-fix usr/gen_init_cpio.c --- 25/usr/gen_init_cpio.c~cygwin-cpio-fix Tue Feb 17 16:42:36 2004 +++ 25-akpm/usr/gen_init_cpio.c Tue Feb 17 16:43:49 2004 @@ -56,7 +56,7 @@ static void cpio_trailer(void) const char name[] = "TRAILER!!!"; sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX" - "%08X%08X%08X%08X%08X%08ZX%08X", + "%08X%08X%08X%08X%08X%08X%08X", "070701", /* magic */ 0, /* ino */ 0, /* mode */ @@ -69,7 +69,7 @@ static void cpio_trailer(void) 0, /* minor */ 0, /* rmajor */ 0, /* rminor */ - strlen(name) + 1, /* namesize */ + (unsigned)strlen(name) + 1, /* namesize */ 0); /* chksum */ push_hdr(s); push_rest(name); @@ -87,7 +87,7 @@ static void cpio_mkdir(const char *name, time_t mtime = time(NULL); sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX" - "%08X%08X%08X%08X%08X%08ZX%08X", + "%08X%08X%08X%08X%08X%08X%08X", "070701", /* magic */ ino++, /* ino */ S_IFDIR | mode, /* mode */ @@ -100,7 +100,7 @@ static void cpio_mkdir(const char *name, 1, /* minor */ 0, /* rmajor */ 0, /* rminor */ - strlen(name) + 1, /* namesize */ + (unsigned)strlen(name) + 1,/* namesize */ 0); /* chksum */ push_hdr(s); push_rest(name); @@ -119,7 +119,7 @@ static void cpio_mknod(const char *name, mode |= S_IFCHR; sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX" - "%08X%08X%08X%08X%08X%08ZX%08X", + "%08X%08X%08X%08X%08X%08X%08X", "070701", /* magic */ ino++, /* ino */ mode, /* mode */ @@ -132,7 +132,7 @@ static void cpio_mknod(const char *name, 1, /* minor */ maj, /* rmajor */ min, /* rminor */ - strlen(name) + 1, /* namesize */ + (unsigned)strlen(name) + 1,/* namesize */ 0); /* chksum */ push_hdr(s); push_rest(name); @@ -176,7 +176,7 @@ void cpio_mkfile(const char *filename, c } sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX" - "%08X%08X%08X%08X%08X%08ZX%08X", + "%08X%08X%08X%08X%08X%08X%08X", "070701", /* magic */ ino++, /* ino */ mode, /* mode */ @@ -189,7 +189,7 @@ void cpio_mkfile(const char *filename, c 1, /* minor */ 0, /* rmajor */ 0, /* rminor */ - strlen(location) + 1, /* namesize */ + (unsigned)strlen(location) + 1,/* namesize */ 0); /* chksum */ push_hdr(s); push_string(location); _