[Toybox] Fw: Building Linux with Toybox

Wed Sep 2 06:20:14 PDT 2020

On 8/28/20 11:56 AM, Porter, Jeremy wrote:
>> I have RISC-V based cross compiled Linux running busybox. I have a very simple
>> /etc/inittab file like this:
>>
>>   1 ::sysinit:/bin/busybox mount -t proc proc /proc
>>   2 ::sysinit:/bin/busybox mount -t tmpfs tmpfs /tmp
>>   3 ::sysinit:/bin/busybox mount -o remount,rw /dev/htifbd0 /
>>   4 ::sysinit:/bin/busybox --install -s
>>   5 /dev/console::sysinit:-/bin/ash
>>
>> How can I translate this to something toybox can use? I've tried this:
>>
>>   1 mount -t proc proc /proc
>   2 mount -t tmpfs tmpfs /tmp
>   3 mount -o remount,rw /dev/htifbd0 /
>   4 #::sysinit:/bin/toybox --install -s
>   5 #/dev/console::sysinit:-/bin/sh
>   6 exec toybox init

And when you tried it, you saw what output?

###Output below###
/work/qemu5/build/riscv64-softmmu/qemu-system-riscv64 --nographic -m 19000K --kernel /work/rocket-tools/riscv-pk/build/bbl
qemu-system-riscv64: warning: No -bios option specified. Not loading a firmware.
qemu-system-riscv64: warning: This default will change in a future QEMU release. Please use the -bios option to avoid breakages when this happens.
qemu-system-riscv64: warning: See QEMU's deprecation documentation for details.
bbl loader
OF: fdt: Ignoring memory range 0x80000000 - 0x80200000
Linux version 5.8.0 (porterjl at rdrydl0-044816) (riscv64-unknown-linux-gnu-gcc (GCC) 7.2.0, GNU ld (GNU Binutils) 2.29) #107 Fri Aug 28 07:12:33 EDT 2020
Zone ranges:
  DMA32    [mem 0x0000000080200000-0x000000008128dfff]
  Normal   empty
Movable zone start for each node
Early memory node ranges
  node   0: [mem 0x0000000080200000-0x000000008128dfff]
Initmem setup node 0 [mem 0x0000000080200000-0x000000008128dfff]
software IO TLB: Cannot allocate buffer
SBI specification v0.1 detected
riscv: ISA extensions acdfimsu
riscv: ELF capabilities acdfim
Built 1 zonelists, mobility grouping on.  Total pages: 4180
Kernel command line:
Dentry cache hash table entries: 4096 (order: 3, 32768 bytes, linear)
Inode-cache hash table entries: 2048 (order: 2, 16384 bytes, linear)
Sorting __ex_table...
mem auto-init: stack:off, heap alloc:off, heap free:off
Memory: 8040K/16952K available (823K kernel code, 3374K rwdata, 2048K rodata, 372K init, 201K bss, 8912K reserved, 0K cma-reserved)
NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0
riscv-intc: 64 local interrupts mapped
riscv_timer_init_dt: Registering clocksource cpuid [0] hartid [0]
clocksource: riscv_clocksource: mask: 0xffffffffffffffff max_cycles: 0x24e6a1710, max_idle_ns: 440795202120 ns
sched_clock: 64 bits at 10MHz, resolution 100ns, wraps every 4398046511100ns
printk: console [hvc0] enabled
Calibrating delay loop (skipped), value calculated using timer frequency.. 20.00 BogoMIPS (lpj=40000)
pid_max: default: 4096 minimum: 301
Mount-cache hash table entries: 512 (order: 0, 4096 bytes, linear)
Mountpoint-cache hash table entries: 512 (order: 0, 4096 bytes, linear)
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041785100000 ns
clocksource: Switched to clocksource riscv_clocksource
workingset: timestamp_bits=62 max_order=11 bucket_order=0
Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254)
random: get_random_bytes called from 0xffffffff802049bc with crng_init=0
Freeing unused kernel memory: 372K
Run /init as init process
Started init

###End Output###

>Toybox init is still in pending, and thus isn't in the defconfig build. It
>hasn't undergone the full https://urldefense.com/v3/__https://landley.net/toybox/cleanup.html__;!!KGKeukY!l7f45aEjunFct2lAgh4PDXhjANSCxgr8ttibt-bfdygS30JJiBTR4QnjWXtLgD9rdq9bWHVPI8jHzw$  review yet, so
>I couldn't tell you what it does. (I'm told it worked for the people who
>submitted it...)
>
>Toybox has a built-in system builder:
>
  https://urldefense.com/v3/__https://landley.net/toybox/faq.html*mkroot__;Iw!!KGKeukY!l7f45aEjunFct2lAgh4PDXhjANSCxgr8ttibt-bfdygS30JJiBTR4QnjWXtLgD9rdq9bWHWy5UZWrw$
>

I've been trying to get this working but I get:

./scripts/mkroot.sh
Building natively
/usr/bin/ld: cannot find -lc
collect2: error: ld returned 1 exit status
Warning: host compiler can't create static binaries.
cleaned
gcc -o kconfig/conf kconfig/conf.c kconfig/zconf.tab.c -DKBUILD_NO_NLS=1 \
        -DPROJECT_NAME=\"ToyBox\"
scripts/genconfig.sh
yes '' | kconfig/conf -o Config.in > /dev/null
scripts/make.sh
Generate headers from toys/*/*.c...
generated/newtoys.h Library probe...........
Make generated/config.h from .config.
generated/flags.h generated/globals.h generated/tags.h generated/help.h
Compile toybox....................../usr/bin/ld: cannot find -lc
collect2: error: ld returned 1 exit status
make: *** [toybox] Error 1

I'm also using RISC-V so I'd have to add a target to the script. I don't mind doing that, but I want to get something simple working first.

>And the init script it uses starts at:

  https://urldefense.com/v3/__https://github.com/landley/toybox/blob/master/scripts/mkroot.sh*L73__;Iw!!KGKeukY!l7f45aEjunFct2lAgh4PDXhjANSCxgr8ttibt-bfdygS30JJiBTR4QnjWXtLgD9rdq9bWHXm0BlkZQ$

>Which ends by calling "oneit", a very simple init program that runs a single
>child process (with /dev/console pointing to a proper tty with signal support),
>and reboots the system when that child exits.
>
>Unfortunately the systems created by that system builder use 2 commands out of
>pending (sh and route), and sh is under active development which means I broke
>it recently. I added proper ${var:thingy} parsing, but haven't implemented
>${var/search/replace} yet, which that init script uses. The current shell parses
>it properly, but throws an error when it tries to _do_ it, because:
>
https://urldefense.com/v3/__https://github.com/landley/toybox/blob/master/toys/pending/sh.c*L1205__;Iw!!KGKeukY!l7f45aEjunFct2lAgh4PDXhjANSCxgr8ttibt-bfdygS30JJiBTR4QnjWXtLgD9rdq9bWHWyB268bA$
>
>Which means the make root init script won't currently work as is, but I plan to
>fix it up before cutting the next release. At the moment implementing "case"
>statements and wildcard support, need to cycle back around to finishing the
>variable expansion...
>
>The downside of the project not being to 1.0 yet. :)

I actually don't need route or sh. My system is a very minimal. I suppose sh could be useful to get something happening in toybox init or oneit, but I don't have any specific requirements for it. I can put it in to get it working--it's still smaller than busybox.

>> It's starting partially (I think) but I'm not quite sure how to troubleshoot
>> this.

>Without seeing what it produced, I can't either.

> My goal is to have a very small Linux. It's around 3 MB file size right
> now and takes about 5 MB of memory when booted. It looks like toybox might go a
> little smaller if I can get it working.

>Try running /bin/sh as pid 1, and run your statements from the command line to
> see what they do?

I don't have sh, but I can put it in to do this.

>You can also stick in "echo" statements to see what's being output, although if
>your initramfs hasn't got a /dev/console entry you won't have a stdout until you
>mount devtmpfs and redirect it yourself, but it looks like you're using
>/dev/htifbd0 as your root so presumably you're using the root= fallback logic
>which creates a temporary /dev/console node to attach PID 1's stdin/out/err to,
>so this doesn't apply to that case...

Again, I don't have echo, but I can put it in and try this. I gave it a try, but I'm having some issues with the build (I suspect).

>Rob
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