Problems running Guix System initrd on an i.MX6 ARM board

[Maxim Cournoyer]

Hi Guix!

I've been trying for some time to run Guix System on an ARM board (a
TS-7970 with an i.MX6 Cortex A9 CPU).  I wanted to cross-compile the
image for speed and efficiency, and stumbled upon some problems on the
way, such as https://issues.guix.gnu.org/44924, fixed on core-updates.

Then it took me some time to figure out that Guile 3.0.7 was segfaulting
when running the initrd's init script, which would cause the following
kernel panic and backtrace:

--8<---------------cut here---------------start------------->8---
[    5.913371] ALSA device list:
[    5.913374]   #0: On-board Codec
[    5.913376]   #1: imx-hdmi-soc
[    5.921483] sdhci-esdhc-imx 2190000.usdhc: card claims to support voltages 
below defined range
[    5.938332] mmc0: new SDIO card at address 0001
[    5.987225] mmc2: new DDR MMC card at address 0001
[    5.998025] mmcblk2: mmc2:0001 MMC04G 3.60 GiB
[    6.009623] mmcblk2boot0: mmc2:0001 MMC04G partition 1 16.0 MiB
[    6.020181] mmcblk2boot1: mmc2:0001 MMC04G partition 2 16.0 MiB
[    6.031772] mmcblk2rpmb: mmc2:0001 MMC04G partition 3 128 KiB
[    6.957080] Freeing unused kernel memory: 1024K (80e00000 - 80f00000)
[    6.967865] Kernel panic - not syncing: Attempted to kill init! 
exitcode=0x00008b00
[    6.967865]
[    6.977015] CPU3: stopping
[    6.979732] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 4.9.11-tsimx #1
[    6.986174] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[    6.992704] Backtrace:
[    6.995189] [<80111d48>] (dump_backtrace) from [<80111f38>] 
(show_stack+0x18/0x1c)
[    7.002765]  r7:00000000 r6:20000193 r5:00000000 r4:80f2fecc
[    7.008437] [<80111f20>] (show_stack) from [<8054d61c>] 
(dump_stack+0x80/0x9c)
[    7.015669] [<8054d59c>] (dump_stack) from [<8010d8dc>] 
(handle_IPI+0xe0/0x178)
[    7.022981]  r7:00000000 r6:d80b1f18 r5:00000003 r4:80e7f034
[    7.028648] [<8010d7fc>] (handle_IPI) from [<801014d8>] 
(gic_handle_irq+0x70/0x78)
[    7.036222]  r7:f4a01100 r6:80f0358c r5:f4a00100 r4:d80b1f18
[    7.041895] [<80101468>] (gic_handle_irq) from [<80a0a34c>] 
(__irq_svc+0x6c/0xa8)
[    7.049380] Exception stack(0xd80b1f18 to 0xd80b1f60)
[    7.054434] 1f00:                                                       
00000000 00000001
[    7.062617] 1f20: 59eaf000 dad2fec0 9fdcb41d 9f4ecbfd dad2f1a8 00000000 
00000001 00000000
[    7.070800] 1f40: 00000001 d80b1f9c d80b1f68 d80b1f68 80826350 80826374 
60000113 ffffffff
[    7.078981]  r7:d80b1f4c r6:ffffffff r5:60000113 r4:80826374
[    7.084651] [<80826284>] (cpuidle_enter_state) from [<80826488>] 
(cpuidle_enter+0x1c/0x20)
[    7.092921]  r10:d80b1fc0 r9:80e801a0 r8:80f030f4 r7:d80b0000 r6:00000003 
r5:80f08cd4
[    7.100752]  r4:dad2f1a8
[    7.103301] [<8082646c>] (cpuidle_enter) from [<80165ccc>] 
(call_cpuidle+0x3c/0x40)
[    7.110966] [<80165c90>] (call_cpuidle) from [<80165f48>] 
(cpu_startup_entry+0x188/0x1a8)
[    7.119149] [<80165dc0>] (cpu_startup_entry) from [<8010d5b8>] 
(secondary_start_kernel+0x134/0x164)
[    7.128196]  r7:80f8d320 r4:80f14490
[    7.131779] [<8010d484>] (secondary_start_kernel) from [<1010156c>] 
(0x1010156c)
[    7.139178]  r7:80f8d320 r6:10c03c7d r5:00000051 r4:6809806a
[    7.144839] CPU1: stopping
[    7.147554] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.9.11-tsimx #1
[    7.153996] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[    7.160524] Backtrace:
[    7.162999] [<80111d48>] (dump_backtrace) from [<80111f38>] 
(show_stack+0x18/0x1c)
[    7.170573]  r7:00000000 r6:20000193 r5:00000000 r4:80f2fecc
[    7.176242] [<80111f20>] (show_stack) from [<8054d61c>] 
(dump_stack+0x80/0x9c)
[    7.183471] [<8054d59c>] (dump_stack) from [<8010d8dc>] 
(handle_IPI+0xe0/0x178)
[    7.190783]  r7:00000000 r6:d80adf18 r5:00000001 r4:80e7f034
[    7.196449] [<8010d7fc>] (handle_IPI) from [<801014d8>] 
(gic_handle_irq+0x70/0x78)
[    7.204022]  r7:f4a01100 r6:80f0358c r5:f4a00100 r4:d80adf18
[    7.209689] [<80101468>] (gic_handle_irq) from [<80a0a34c>] 
(__irq_svc+0x6c/0xa8)
[    7.217173] Exception stack(0xd80adf18 to 0xd80adf60)
[    7.222227] df00:                                                       
00000000 00000001
[    7.230410] df20: 59e93000 dad13ec0 9fdcb2cf 9f4ecbfd dad131a8 00000000 
00000001 00000000
[    7.238592] df40: 00000001 d80adf9c d80adf68 d80adf68 80826350 80826374 
60000013 ffffffff
[    7.246773]  r7:d80adf4c r6:ffffffff r5:60000013 r4:80826374
[    7.252439] [<80826284>] (cpuidle_enter_state) from [<80826488>] 
(cpuidle_enter+0x1c/0x20)
[    7.260709]  r10:d80adfc0 r9:80e801a0 r8:80f030f4 r7:d80ac000 r6:00000001 
r5:80f08cd4
[    7.268539]  r4:dad131a8
[    7.271082] [<8082646c>] (cpuidle_enter) from [<80165ccc>] 
(call_cpuidle+0x3c/0x40)
[    7.278746] [<80165c90>] (call_cpuidle) from [<80165f48>] 
(cpu_startup_entry+0x188/0x1a8)
[    7.286931] [<80165dc0>] (cpu_startup_entry) from [<8010d5b8>] 
(secondary_start_kernel+0x134/0x164)
[    7.295979]  r7:80f8d320 r4:80f14490
[    7.299560] [<8010d484>] (secondary_start_kernel) from [<1010156c>] 
(0x1010156c)
[    7.306959]  r7:80f8d320 r6:10c03c7d r5:00000051 r4:6809806a
[    7.312621] CPU2: stopping
[    7.315337] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.9.11-tsimx #1
[    7.321779] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[    7.328306] Backtrace:
[    7.330780] [<80111d48>] (dump_backtrace) from [<80111f38>] 
(show_stack+0x18/0x1c)
[    7.338355]  r7:00000000 r6:20000193 r5:00000000 r4:80f2fecc
[    7.344024] [<80111f20>] (show_stack) from [<8054d61c>] 
(dump_stack+0x80/0x9c)
[    7.351254] [<8054d59c>] (dump_stack) from [<8010d8dc>] 
(handle_IPI+0xe0/0x178)
[    7.358567]  r7:00000000 r6:d80aff18 r5:00000002 r4:80e7f034
[    7.364232] [<8010d7fc>] (handle_IPI) from [<801014d8>] 
(gic_handle_irq+0x70/0x78)
[    7.371806]  r7:f4a01100 r6:80f0358c r5:f4a00100 r4:d80aff18
[    7.377472] [<80101468>] (gic_handle_irq) from [<80a0a34c>] 
(__irq_svc+0x6c/0xa8)
[    7.384956] Exception stack(0xd80aff18 to 0xd80aff60)
[    7.390010] ff00:                                                       
00000000 dad24bc0
[    7.398192] ff20: 00000001 d80ae000 9fdcb6b7 9fca06dd dad211a8 00000001 
00000001 00000004
[    7.406375] ff40: 00000001 d80aff9c d80aff28 d80aff68 8018eb00 80826374 
20000013 ffffffff
[    7.414555]  r7:d80aff4c r6:ffffffff r5:20000013 r4:80826374
[    7.420222] [<80826284>] (cpuidle_enter_state) from [<80826488>] 
(cpuidle_enter+0x1c/0x20)
[    7.428493]  r10:d80affc0 r9:80e801a0 r8:80f030f4 r7:d80ae000 r6:00000002 
r5:80f08cd4
[    7.436323]  r4:dad211a8
[    7.438866] [<8082646c>] (cpuidle_enter) from [<80165ccc>] 
(call_cpuidle+0x3c/0x40)
[    7.446531] [<80165c90>] (call_cpuidle) from [<80165f48>] 
(cpu_startup_entry+0x188/0x1a8)
[    7.454714] [<80165dc0>] (cpu_startup_entry) from [<8010d5b8>] 
(secondary_start_kernel+0x134/0x164)
[    7.463761]  r7:80f8d320 r4:80f14490
[    7.467342] [<8010d484>] (secondary_start_kernel) from [<1010156c>] 
(0x1010156c)
[    7.474742]  r7:80f8d320 r6:10c03c7d r5:00000051 r4:6809806a
[    7.480414] ---[ end Kernel panic - not syncing: Attempted to kill init! 
exitcode=0x00008b00
[    7.480414]
--8<---------------cut here---------------end--------------->8---

I found that guile would segfault and return an exit code of 139
(perhaps ETXTBSY, per guile sources), by adding bash-static to the
initrd and invoking guile from there during the early boot.

Luckily, Guile 3.0.8 doesn't have this problem, so the following fixed
it:

--8<---------------cut here---------------start------------->8---
modified   gnu/packages/make-bootstrap.scm
@@ -797,7 +797,7 @@ (define %guile-static-stripped
   ;; A stripped static Guile 3.0 binary, for use in initrds
   ;; and during bootstrap.
   (make-guile-static-stripped
-   (make-guile-static guile-3.0
+   (make-guile-static guile-3.0-latest
                       '("guile-2.2-default-utf8.patch"
                         "guile-3.0-linux-syscalls.patch"
                         "guile-3.0-relocatable.patch"))))
--8<---------------cut here---------------end--------------->8---

The initrd now runs, but it fails with the following error:

--8<---------------cut here---------------start------------->8---
[    8.448448] ALSA device list:
[    8.451472]   #0: On-board Codec
[    8.454768]   #1: imx-hdmi-soc
[    8.461095] Freeing unused kernel memory: 1024K (80e00000 - 80f00000)
GC Warning: pthread_getattr_np or pthread_attr_getstack failed for main thread
GC Warning: Couldn't read /proc/stat
[    8.481168] mmc0: new SDIO card at address 0001
Welcome, this is GNU's early boot Guile.
Use 'gnu.repl' for an initrd REPL.

ice-9/boot-9.scm:1685:16: In procedure raise-exception:
Throw to key `record-abi-mismatch-error' with args `(abi-check "~a: record ABI 
mismatch; recompilation needed" (#<record-type <file-system>>) ())'.

Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
GNU Guile 3.0.8
Copyright (C) 1995-2021 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guile-user)>
--8<---------------cut here---------------end--------------->8---

The .go modules appear to be correctly cross-compiled for
arm-linux-gnueabihf (they run fine on the same target using a different
OS that I can boot with).

Ideas?

-- 
Thanks,
Maxim