On x86, when both CONFIG_GRUB_CONSOLE and CONFIG_GRUB_SERIAL are set (as
they are by default), the kernel command line will have two console=
entries, such as
console=tty0 console=ttyS0,115200n8
Failsafe was only running a shell on the first defined console, the VGA
console. This is a problem for devices like apu2, where there is only a
serial console and it appears on ttyS0.
Moreover, the console prompt to enter failsafe during boot was delivered
to, and its input read from, the last console= on the kernel command
line. So while the failsafe shell was on the first defined console, only
the last defined console could be used to enter failsafe during boot.
In contrast, the x86 bootloader (GRUB) operates on both the serial
console and the VGA console by virtue of "terminal_{input,output}
console serial". GRUB also provided an alternate means to enter failsafe
from either console. The presence of two console= kernel command line
parameters causes kernel messages to be delivered to both. Under normal
operation (not failsafe), procd runs login in accordance with inittab,
which on x86 specifies ttyS0, hvc0, and tty1, allowing login through any
of serial, hypervisor, or VGA console. Thus, serial access was
consistently available on x86 devices with serial consoles under normal
operation, except for shell access in failsafe mode (without editing the
kernel command line).
By presenting the failsafe prompt, reading failsafe prompt input, and
running failsafe shells on all consoles listed in /proc/cmdline,
failsafe mode will work correctly on devices with a serial console (like
apu2), and the same image without any need for reconfiguration can be
shared by devices with the more traditional (for x86) VGA console. This
improvement should benefit any system with multiple console= arguments,
including x86 and bcm27xx (Raspberry Pi).
Signed-off-by: Mark Mentovai <mark at moxienet.com>
This drops the shebang from another bunch of files in various /lib
folders, as these are sourced and the shebang is useless.
Fix execute bit in one case, too.
This should cover almost all trivial cases now, i.e. where /lib is
actually used for library files.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
This replaces deprecated backticks by more versatile $(...) syntax.
This does not touch lib/upgrade/nand.sh, as there replacement is
not trivial.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
The preinit network initialisation and failsafe informational message
are inherently racy as the interface takes some time to become
functional after "ip link set $pi_ifname up" command.
Consider this timing:
[ 12.002713] IPv6: ADDRCONF(NETDEV_UP): eth1: link is not ready
[ 12.008819] IPv6: ADDRCONF(NETDEV_UP): eth1.1: link is not ready
[ 12.118877] random: procd: uninitialized urandom read (4 bytes read)
[ 13.068614] eth1: link up (1000Mbps/Full duplex)
[ 13.073309] IPv6: ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready
[ 13.080445] IPv6: ADDRCONF(NETDEV_CHANGE): eth1.1: link becomes ready
Since the UDP message was sent prior to link becoming ready, it was
never seen on the wire.
The default failsafe timeout is set to 2 seconds, so with this patch
there are two attempts to send the message, one spent in vain, and the
other visible in tcpdump on an attached host. Of course, in cases when
the interface is brought up faster it leads to two messages, however it
should be harmless. This patch (almost) doesn't affect normal boot time
while still allowing to enter failsafe reliably with a single button
press, matching the official "generic failsafe" documentation.
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
