| 1 |
On Fri, Aug 5, 2011 at 10:37 PM, William Hubbs <williamh@g.o> wrote: |
| 2 |
> Hi Rich, |
| 3 |
> |
| 4 |
> On Fri, Aug 05, 2011 at 09:04:50PM -0400, Rich Freeman wrote: |
| 5 |
>> On Fri, Aug 5, 2011 at 8:42 PM, William Hubbs <williamh@g.o> wrote: |
| 6 |
>> > On Fri, Aug 05, 2011 at 10:06:48PM +0200, Sven Vermeulen wrote: |
| 7 |
>> >> How does the tool that creates an initramfs know which files to copy from |
| 8 |
>> >> /usr and /var anyhow? |
| 9 |
>> > |
| 10 |
>> > My understanding is that nothing gets copied from /usr and /var, and it |
| 11 |
>> > doesn't have to. |
| 12 |
>> > |
| 13 |
>> > Here is my basic understanding of how the boot sequence works: |
| 14 |
>> > |
| 15 |
>> > 1) rootfs is mounted on /. Rootfs contains the contents of the |
| 16 |
>> > initramfs. |
| 17 |
>> |
| 18 |
>> Ok, so the initfs is typically in /boot, though it need not be. It |
| 19 |
>> needs to be someplace the bootloader can find it, and with grub legacy |
| 20 |
>> that typically means on a bare hard drive partition, or one using md |
| 21 |
>> raid-1 with older metadata. The initramfs doesn't need to find itself |
| 22 |
>> - the bootloader loads it into ram and passes its address to the |
| 23 |
>> kernel when executing it. |
| 24 |
> |
| 25 |
> Not quite. It is actually inside the kernel binary. You are thinking of |
| 26 |
> an initrd. |
| 27 |
> |
| 28 |
> Look at these files: |
| 29 |
> |
| 30 |
> /usr/src/linux/Documentation/filesystems/ramfs-rootfs-initramfs.txt. |
| 31 |
> /usr/src/linux/Documentation/early-userspace/README |
| 32 |
> |
| 33 |
|
| 34 |
The initramfs cpio archive does not HAVE to be inside the kernel |
| 35 |
binary. It may be assembled as a separate file (perhaps in /boot), and |
| 36 |
passed to the kernel by the bootloader, just as Rich describes. |
| 37 |
|
| 38 |
See the section "External initramfs images" in ramfs-rootfs-initramfs.txt. |
Archives