system: expose if system was booted from initramfs

It can be good for UI to show to the user that the system was booted
from initramfs ie. no writable permanent storage is available.
I imagine LuCI only serving applications which are explicitely marked
as being shown even in initramfs mode, ie. nothing but status,
network->interfaces, network->wireless, system->upgrade,
system->backup, system->backuprestore tabs.
Also sysupgrade could take into account we are running on initramfs
and perform offline backup/restore of whatever is in the flash.
In that way OpenWrt-generated initramfs-images can serve as recovery
OS on devices with dual-boot in a meaningful way.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

diff --git a/initd/preinit.c b/initd/preinit.c
index 9dfe5c17576fbd2fcb19ee887e054e3ee24c6464..46411aa413a2a65614cfc765d3d6a42dee200532 100644 (file)
--- a/initd/preinit.c
+++ b/initd/preinit.c
@@ -97,7 +97,6 @@ spawn_procd(struct uloop_process *proc, int ret)
        if (plugd_proc.pid > 0)
                kill(plugd_proc.pid, SIGKILL);
 
-       unsetenv("INITRAMFS");
        unsetenv("PREINIT");
        unlink("/tmp/.preinit");
 

diff --git a/system.c b/system.c
index 7855659d79710c9e742b1fd00d8c674f10cf738f..83aea423ec6aaceedca54e42aea18ce90d7ddfa1 100644 (file)
--- a/system.c
+++ b/system.c
@@ -36,6 +36,7 @@
 static struct blob_buf b;
 static int notify;
 static struct ubus_context *_ctx;
+static int initramfs;
 
 enum vjson_state {
        VJSON_ERROR,
@@ -55,6 +56,9 @@ static int system_board(struct ubus_context *ctx, struct ubus_object *obj,
 
        blob_buf_init(&b, 0);
 
+       if (initramfs)
+               blobmsg_add_u8(&b, "initramfs", 1);
+
        if (uname(&utsname) >= 0)
        {
                blobmsg_add_string(&b, "kernel", utsname.release);
@@ -759,6 +763,11 @@ void ubus_init_system(struct ubus_context *ctx)
        int ret;
 
        _ctx = ctx;
+
+       initramfs = !!getenv("INITRAMFS");
+       if (initramfs)
+               unsetenv("INITRAMFS");
+
        ret = ubus_add_object(ctx, &system_object);
        if (ret)
                ERROR("Failed to add object: %s\n", ubus_strerror(ret));