[archiso] Add archiso_pxe_curl hook

Its add support for downloading the ISO image via HTTP/FTP with curl or download *.sfs files.
The files are downloaded on /run/archiso/curlspace (tmpfs) and setup a loop dev from it
(like in archiso_loop_mnt) in the ISO case, or just do a bind mount to
/run/archiso/bootmnt in the other case.

This hook must be located after archiso_pxe_nbd in mkinitcpio.conf, in that way
NBD is the default.

New bootparm:
* archiso_curl_url=(first form)
    archiso_curl_url=http://192.168.0.7/archlinux/iso/archlinux.iso (absolute form)
        Use an absolute URL. Fetch the entire ISO
    archiso_curl_url=ftp://${pxeserver}/archlinux/iso/archlinux.iso (relative form)
        Use the as IP the same server where PXE reside.  Fetch the entire ISO

* archiso_curl_url=(second form)
    archiso_curl_url=http://192.168.0.7/archlinux/iso/unpacked (absolute form)
        Use an absolute URL. Where unpacked (an example name) is a directory where
        ${archisobasedir} ("arch" by default) is located with all *.sfs.
        This fetch only needed files.
    archiso_curl_url=ftp://${pxeserver}/archlinux/iso/unpacked (relative form)
        Use the as IP the same server where PXE reside. Where unpacked (an example name)
        is a directory where ${archisobasedir} ("arch" by default)
        is located with all *.sfs. This fetch only needed files.

* curlspace_size= Set a size for a tmpfs filesystem where files are downloaded.

Signed-off-by: Gerardo Exequiel Pozzi <vmlinuz386@yahoo.com.ar>

1 files changed, 15 insertions, 0 deletions

diff --git a/README b/README
index 0dd2179..dede082 100644
--- a/README
+++ b/README
@@ -74,6 +74,7 @@ INDEX
                     BOOTIF=<hardware-address-of-boot-interface>
                     Default: (set via PXELINUX)
 
+
 ** hooks/archiso_pxe_nbd
 
 * archiso_nbd_name= Set NBD export name used by the server.
@@ -82,6 +83,18 @@ INDEX
                     Default: "${pxeserver}" (The <boot-server-ip from ip=)
 
 
+** hooks/archiso_pxe_curl
+
+* archiso_curl_url= Set an HTTP/FTP URL of an ISO file (first form),
+                    or a path (must end with /) where ${archisobasedir}
+                    is found with all *.sfs files (second form).
+                    In the IP part if ${pxeserver} is used, PXE IP will be used.
+                    Default: (unset)
+* curlspace_size=   Set the size of tmpfs of "curlspace" where the specified
+                    ISO image or *.sfs files are downloaded.
+                    Default: "75%"
+
+
 ** hooks/archiso_loop_mnt
 
 * img_label=        Set the filesystem label where archiso-image.iso.
@@ -127,6 +140,8 @@ if nothing is specified on command line.
  + mkinitcpio-nfs-utils    for ipconfig
 * archiso_pxe_nbd
  + nbd                     for nbd-client
+* archiso_pxe_curl
+ + curl                    for curl
 * archiso_shutdown
  + (none)