Determining build source files for a specific target (ar71xx/ath79)

For Developers
1

Hi all,

I'm rather new to the OpenWrt build system and in kernel dev as a whole, so still the learning curve is steep.

As a vehicle, I chose to upgrade a WR940NDv1.2 (that's the label on the router itself).

router_board
router_board1530×2048 631 KB

Looking into the forums and documentation, this board matches the WR941NDv4 so, I thought makes sense to configure build using that.
menuconfig
menuconfig529×559 5.11 KB

At some stage I wanted to experiment touching source files during kernel boot just for the sake of hello world experience. I tried adding printk() and pr_info() calls in arch/mips/ath79/tl-wr941nd.c files but whatever I did was not reflected in the bootlog. After some trials I noticed that the log file actually says board image is actually WR741ND!

OpenWrt kernel loader for AR7XXX/AR9XXX
Copyright (C) 2011 Gabor Juhos juhosg@openwrt.org
Looking for OpenWrt image... found at 0xbf022000
Decompressing kernel... done!
Starting kernel at 80060000...

[    0.000000] Linux version 4.14.180 () (gcc version 7.5.0 (OpenWrt GCC 7.5.0 r11063-85e04e9f46)) #0 Sat May 16 18:32:20 2020
[    0.000000] bootconsole [early0] enabled
[    0.000000] CPU0 revision is: 00019374 (MIPS 24Kc)
[    0.000000] SoC: Atheros AR7240 rev 2
[    0.000000] Determined physical RAM map:
[    0.000000]  memory: 02000000 @ 00000000 (usable)
[    0.000000] Initrd not found or empty - disabling initrd
[    0.000000] Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes.
[    0.000000] Primary data cache 32kB, 4-way, VIPT, cache aliases, linesize 32 bytes
[    0.000000] Zone ranges:
[    0.000000]   Normal   [mem 0x0000000000000000-0x0000000001ffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000000000000-0x0000000001ffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x0000000001ffffff]
[    0.000000] random: get_random_bytes called from 0x8042f6ec with crng_init=0
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 8128
[    0.000000] Kernel command line: board=**TL-WR741ND**  console=ttyS0,115200 rootfstype=squashfs noinitrd
[    0.000000] PID hash table entries: 128 (order: -3, 512 bytes)
[    0.000000] Dentry cache hash table entries: 4096 (order: 2, 16384 bytes)
[    0.000000] Inode-cache hash table entries: 2048 (order: 1, 8192 bytes)
[    0.000000] Writing ErrCtl register=00000000
[    0.000000] Readback ErrCtl register=00000000
[    0.000000] Memory: 27744K/32768K available (3280K kernel code, 168K rwdata, 444K rodata, 196K init, 199K bss, 5024K reserved, 0K cma-reserved)
[    0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.000000] NR_IRQS: 51

Of course, when I modified the mach-tl-wr741nd.c file the changes were reflected in the log file as expected. So my question is why would there be a mismatch between menuconfig and the actual build and how could one predetermine which files are going to be built for a specific image?

Thanks,
Dimitar

2

But it looks like you are trying with the deprecated (= to be removed) ar71xx target, instead of the current ath79 target.

Kernel 4.14 support and ar71xx is to be removed soon.

1 Like
3

Thanks for the tip, indeed ath79 offers wr941nd-v4 build.
However, I am trying to find board-specific setup code for this router under /target/linux/ath79, like previously when I was using the the linux/ar71xx/files/arch/mips/ath79/mach-tl-wr941nd.c . Any ideas where could that be located?

4

It is now in the DTS definition... "Devicetree"

Device tl-wr941-v4:
https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob;f=target/linux/ath79/dts/ar7240_tplink_tl-wr941-v4.dts;h=c8fe835e7eb22d824ad9846fc7acf1db68d001de;hb=HEAD

Included family "ar7240_tplink_tl-wr":
https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob;f=target/linux/ath79/dts/ar7240_tplink_tl-wr.dtsi;h=5ceada8375622675f9b1e0b02960715da0d73a09;hb=HEAD

Included upper family "ar7240_tplink":
https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob;f=target/linux/ath79/dts/ar7240_tplink.dtsi;h=de0b36bbf8ea6bd7a2955d8ff494d8daf612ea63;hb=HEAD

Included chip "ar7240":
https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob;f=target/linux/ath79/dts/ar7240.dtsi;h=730c509d7bdf625e61bf8937ab7034e6b11881ee;hb=HEAD

As you see from those, you can piggyback on the common things, and only have a small file where the device-specific differences are.

Example of recent devices:

"TP-Link TL-WR710N v2.1"
https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=eb531337a779a48a2d17bc66f0d222325d6c1563

"TP-Link TL-WA801ND v3/v4"
https://git.openwrt.org/?p=openwrt/openwrt.git;a=commitdiff;h=9a477b833ab2aea96b9eee55acb5f9e7b01b36d8;hp=583b3e40254076693eb5227a9d9ae49eb2b0bcbf

You might read the discussions in the ar71xx-->ath79 porting guide thread:

1 Like
5

I guess that's exactly what I was looking for, thanks for the flash response!

6

So I've reached the point in migrating the WR941NDv4 to ath79 where I'm a bit stuck. You see, for this board I have replaced the flash chip with 8M and attached USB receptacle, where I was able to mount external usb stick and use it as storage.

For what I understood, in the ath79 platform I need to touch the spi0 section to accomodate larger flash and adjust art partition location and also enable the usb.
So to ar7240_tplink_tl-wr941-v4.dts I added

&spi {
	flash@0 {
		partitions {
			firmware: partition@20000 {
				reg = <0x20000 0x7d0000>;
			};
			art: partition@3f0000 {
				reg = <0x7f0000 0x10000>;
			};
		};
	};
};

and also modified the status field in ar7240.dtsi

/ {
	usb_phy: usb-phy {
....
		status = "enabled";
	};
};

&ahb {
	usb: usb@1b000000 {
....
		status = "enabled";
	};
};

Now, the router boots up, the kernel log shows that USB drivers are loaded, but there is no activity on the usb stick and no device appears as /dev/sd*.

From the menuconfig I've added usb-core, usb2, storage and some filesystem support, but no matter the device I plug in there is no driver response. In the ar71xx I used to register the usb driver via ath79_register_usb() call, but this now should be avoided by use of dts, right?

Has someone had similar issues?

7

To enable usb you should only reference the node which you wanna modify like:

&usb {
    status = "okay";
};

&usb_phy {
    status = "okay";
};

And there is no "enabled", this is achieved by setting it to "okay".

For further assistance, please post your bootlog from the dmesg command...

8

Hi,

USB drivers do get registered now

U-Boot 1.1.4 (Mar  8 2010 - 10:35:18)

AP93 (ar7240) U-boot
DRAM:
sri
#### TAP VALUE 1 = 7, 2 = 8
32 MB
id read 0x100000ff
flash size 4194304, sector count = 64
Flash:  4 MB
Using default environment

In:    serial
Out:   serial
Err:   serial
Net:   ag7240_enet_initialize...
No valid address in Flash. Using fixed address
: cfg1 0xf cfg2 0x7014
eth0: 00:03:7f:09:0b:ad
eth0 up
No valid address in Flash. Using fixed address
: cfg1 0xf cfg2 0x7214
eth1: 00:03:7f:09:0b:ad
ATHRS26: resetting s26
ATHRS26: s26 reset done
eth1 up
eth0, eth1
Autobooting in 1 seconds
## Booting image at 9f020000 ...
   Uncompressing Kernel Image ... OK

Starting kernel ...



OpenWrt kernel loader for AR7XXX/AR9XXX
Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
Looking for OpenWrt image... found at 0xbf022000
Decompressing kernel... done!
Starting kernel at 80060000...

[    0.000000] Linux version 4.14.180 () (gcc version 7.5.0 (OpenWrt GCC 7.5.0 r11063-85e04e9f46)) #0 Sat May 16 18:32:20 2020
[    0.000000] bootconsole [early0] enabled
[    0.000000] CPU0 revision is: 00019374 (MIPS 24Kc)
[    0.000000] MIPS: machine is TP-Link TL-WR941N/ND v4
[    0.000000] SoC: Atheros AR7240 rev 2
[    0.000000] Determined physical RAM map:
[    0.000000]  memory: 02000000 @ 00000000 (usable)
[    0.000000] Initrd not found or empty - disabling initrd
[    0.000000] Printing from dt init call
[    0.000000] Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes.
[    0.000000] Primary data cache 32kB, 4-way, VIPT, cache aliases, linesize 32 bytes
[    0.000000] Zone ranges:
[    0.000000]   Normal   [mem 0x0000000000000000-0x0000000001ffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000000000000-0x0000000001ffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x0000000001ffffff]
[    0.000000] random: get_random_bytes called from 0x804456ec with crng_init=0
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 8128
[    0.000000] Kernel command line: console=ttyS0,115200 rootfstype=squashfs,jffs2
[    0.000000] PID hash table entries: 128 (order: -3, 512 bytes)
[    0.000000] Dentry cache hash table entries: 4096 (order: 2, 16384 bytes)
[    0.000000] Inode-cache hash table entries: 2048 (order: 1, 8192 bytes)
[    0.000000] Writing ErrCtl register=00000000
[    0.000000] Readback ErrCtl register=00000000
[    0.000000] Memory: 26636K/32768K available (3371K kernel code, 133K rwdata, 476K rodata, 1196K init, 195K bss, 6132K reserved, 0K cma-reserved)
[    0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.000000] NR_IRQS: 51
[    0.000000] CPU clock: 400.000 MHz
[    0.000000] clocksource: MIPS: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 9556302233 ns
[    0.000014] sched_clock: 32 bits at 200MHz, resolution 5ns, wraps every 10737418237ns
[    0.007908] Calibrating delay loop... 265.42 BogoMIPS (lpj=1327104)
[    0.094159] pid_max: default: 32768 minimum: 301
[    0.099074] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[    0.105683] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[    0.118827] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[    0.128699] futex hash table entries: 256 (order: -1, 3072 bytes)
[    0.134895] pinctrl core: initialized pinctrl subsystem
[    0.141520] NET: Registered protocol family 16
[    0.149745] PCI host bridge /ahb/apb/pcie-controller@180c0000 ranges:
[    0.156259]  MEM 0x0000000010000000..0x0000000013ffffff
[    0.161473]   IO 0x0000000000000000..0x0000000000000000
[    0.192622] PCI host bridge to bus 0000:00
[    0.196736] pci_bus 0000:00: root bus resource [mem 0x10000000-0x13ffffff]
[    0.203657] pci_bus 0000:00: root bus resource [io  0x0000]
[    0.209218] pci_bus 0000:00: root bus resource [??? 0x00000000 flags 0x0]
[    0.215995] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff]
[    0.224640] pci 0000:00:00.0: BAR 0: assigned [mem 0x10000000-0x1000ffff 64bit]
[    0.232892] clocksource: Switched to clocksource MIPS
[    0.239504] NET: Registered protocol family 2
[    0.245105] TCP established hash table entries: 1024 (order: 0, 4096 bytes)
[    0.252082] TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
[    0.258506] TCP: Hash tables configured (established 1024 bind 1024)
[    0.265078] UDP hash table entries: 256 (order: 0, 4096 bytes)
[    0.270937] UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
[    0.277593] NET: Registered protocol family 1
[    0.288715] Crashlog allocated RAM at address 0x1f00000
[    0.295936] workingset: timestamp_bits=30 max_order=13 bucket_order=0
[    0.310638] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[    0.316512] jffs2: version 2.2 (NAND) (SUMMARY) (LZMA) (RTIME) (CMODE_PRIORITY) (c) 2001-2006 Red Hat, Inc.
[    0.339989] io scheduler noop registered
[    0.343981] io scheduler deadline registered (default)
[    0.349607] ar7200-usb-phy usb-phy: phy reset is missing
[    0.355600] pinctrl-single 18040028.pinmux: 64 pins at pa b8040028 size 8
[    0.363852] Serial: 8250/16550 driver, 1 ports, IRQ sharing disabled
[    0.371184] console [ttyS0] disabled
[    0.374882] 18020000.uart: ttyS0 at MMIO 0x18020000 (irq = 9, base_baud = 12500000) is a 16550A
[    0.383602] console [ttyS0] enabled
[    0.383602] console [ttyS0] enabled
[    0.390609] bootconsole [early0] disabled
[    0.390609] bootconsole [early0] disabled
[    0.416632] m25p80 spi0.0: s25fl064k (8192 Kbytes)
[    0.421513] 3 fixed-partitions partitions found on MTD device spi0.0
[    0.427926] Creating 3 MTD partitions on "spi0.0":
[    0.432764] 0x000000000000-0x000000020000 : "u-boot"
[    0.439019] 0x000000020000-0x0000007f0000 : "firmware"
[    0.445614] 2 tplink-fw partitions found on MTD device firmware
[    0.451580] Creating 2 MTD partitions on "firmware":
[    0.456649] 0x000000000000-0x00000014e364 : "kernel"
[    0.462739] 0x00000014e364-0x0000007d0000 : "rootfs"
[    0.468889] mtd: device 3 (rootfs) set to be root filesystem
[    0.474693] 1 squashfs-split partitions found on MTD device rootfs
[    0.480924] 0x000000420000-0x0000007d0000 : "rootfs_data"
[    0.487494] 0x0000007f0000-0x000000800000 : "art"
[    0.494402] libphy: Fixed MDIO Bus: probed
[    0.834897] libphy: ag71xx_mdio: probed
[    0.839738] libphy: ar8xxx-mdio: probed
[    0.846798] switch0: Atheros AR724X/AR933X built-in rev. 2 switch registered on mdio-bus.0
[    0.898344] ag71xx 19000000.eth: connected to PHY at mdio-bus.0:1f:04 [uid=004dd041, driver=Generic PHY]
[    0.908944] eth0: Atheros AG71xx at 0xb9000000, irq 4, mode: mii
[    1.254815] ag71xx 1a000000.eth: connected to PHY at fixed-0:00 [uid=00000000, driver=Generic PHY]
[    1.264830] eth1: Atheros AG71xx at 0xba000000, irq 5, mode: gmii
[    1.275056] NET: Registered protocol family 10
[    1.287349] Segment Routing with IPv6
[    1.291180] NET: Registered protocol family 17
[    1.296606] 8021q: 802.1Q VLAN Support v1.8
[    1.310586] VFS: Mounted root (squashfs filesystem) readonly on device 31:3.
[    1.327739] Freeing unused kernel memory: 1196K
[    1.332299] This architecture does not have kernel memory protection.
[    2.562915] random: fast init done
[    3.997861] init: Console is alive
[    4.001593] init: - watchdog -
[    6.170286] kmodloader: loading kernel modules from /etc/modules-boot.d/*
[    6.562444] usbcore: registered new interface driver usbfs
[    6.568176] usbcore: registered new interface driver hub
[    6.573699] usbcore: registered new device driver usb
[    6.623068] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[    6.641596] SCSI subsystem initialized
[    6.652164] ehci-platform: EHCI generic platform driver
[    6.660075] ehci-pci: EHCI PCI platform driver
[    6.668322] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[    6.676456] ohci-platform: OHCI generic platform driver
[    6.682029] ohci-platform 1b000000.usb: Generic Platform OHCI controller
[    6.688897] ohci-platform 1b000000.usb: new USB bus registered, assigned bus number 1
[    6.696911] ohci-platform 1b000000.usb: irq 3, io mem 0x1b000000
[    6.778111] hub 1-0:1.0: USB hub found
[    6.782392] hub 1-0:1.0: 1 port detected
[    6.790567] uhci_hcd: USB Universal Host Controller Interface driver
[    6.799612] ohci-pci: OHCI PCI platform driver
[    6.810086] usbcore: registered new interface driver usb-storage
[    6.819700] usbcore: registered new interface driver uas
[    6.825802] kmodloader: done loading kernel modules from /etc/modules-boot.d/*
[    6.843729] init: - preinit -
[    9.196700] random: jshn: uninitialized urandom read (4 bytes read)
[    9.657164] random: jshn: uninitialized urandom read (4 bytes read)
[    9.978254] random: jshn: uninitialized urandom read (4 bytes read)
[   10.245767] urandom_read: 1 callbacks suppressed
[   10.245779] random: jshn: uninitialized urandom read (4 bytes read)
[   10.341491] random: jshn: uninitialized urandom read (4 bytes read)
[   10.530252] random: jshn: uninitialized urandom read (4 bytes read)
[   11.243856] IPv6: ADDRCONF(NETDEV_UP): eth1: link is not ready
[   11.249830] IPv6: ADDRCONF(NETDEV_UP): eth1.1: link is not ready
Press the [f] key and hit [enter] to enter failsafe mode
Press the [1], [2], [3] or [4] key and hit [enter] to select the debug level
[   12.274069] eth1: link up (1000Mbps/Full duplex)
[   12.278767] IPv6: ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready
[   12.285852] IPv6: ADDRCONF(NETDEV_CHANGE): eth1.1: link becomes ready
[   14.931251] jffs2: notice: (436) jffs2_build_xattr_subsystem: complete building xattr subsystem, 8 of xdatum (2 unchecked, 6 orphan) and 96 of xref (6 dead, 0 orphan) found.
[   14.949694] mount_root: switching to jffs2 overlay
[   14.999714] overlayfs: upper fs does not support tmpfile.
[   15.014580] urandom-seed: Seeding with /etc/urandom.seed
[   15.479886] eth1: link down
[   15.511795] procd: - early -
[   15.514932] procd: - watchdog -
[   16.412965] procd: - watchdog -
[   16.416556] procd: - ubus -
[   16.699573] urandom_read: 1 callbacks suppressed
[   16.699585] random: ubusd: uninitialized urandom read (4 bytes read)
[   16.712446] random: ubusd: uninitialized urandom read (4 bytes read)
[   16.720797] procd: - init -
Please press Enter to activate this console.
[   18.501283] kmodloader: loading kernel modules from /etc/modules.d/*
[   18.526015] ntfs: driver 2.1.32 [Flags: R/O MODULE].
[   18.552369] ip6_tables: (C) 2000-2006 Netfilter Core Team
[   18.570773] Loading modules backported from Linux version v4.19.120-0-gfdc072324f3c
[   18.578563] Backport generated by backports.git v4.19.120-1-0-g60c3a249
[   18.589697] ip_tables: (C) 2000-2006 Netfilter Core Team
[   18.608236] nf_conntrack version 0.5.0 (1024 buckets, 4096 max)
[   18.707493] xt_time: kernel timezone is -0000
[   18.795837] PPP generic driver version 2.4.2
[   18.803922] NET: Registered protocol family 24
[   18.918182] ath: phy0: Ignoring endianness difference in EEPROM magic bytes.
[   18.948494] ieee80211 phy0: Atheros AR9280 Rev:2 mem=0xb0000000, irq=12
[   19.413515] kmodloader: done loading kernel modules from /etc/modules.d/*
[   20.708398] urngd: v1.0.2 started.
[   21.446474] random: crng init done
[   44.386041] IPv6: ADDRCONF(NETDEV_UP): eth1: link is not ready
[   44.393131] eth1: link up (1000Mbps/Full duplex)
[   44.398383] IPv6: ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready
[   44.438570] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[   47.998750] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[   52.174777] wlan0: authenticate with 00:27:19:d2:dc:c2
[   52.195342] wlan0: send auth to 00:27:19:d2:dc:c2 (try 1/3)
[   52.213267] wlan0: authenticated
[   52.243007] wlan0: associate with 00:27:19:d2:dc:c2 (try 1/3)
[   52.253333] wlan0: RX AssocResp from 00:27:19:d2:dc:c2 (capab=0x431 status=0 aid=3)
[   52.261505] wlan0: associated
[   52.283670] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[   58.698338] eth0: link up (10Mbps/Full duplex)
[   58.702963] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes

but when I plug in the USB stick I get the following event:

[   66.042927] usb 1-1: new full-speed USB device number 2 using ohci-platform
[   66.332908] ohci-platform 1b000000.usb: frame counter not updating; disabled
[   66.340023] ohci-platform 1b000000.usb: HC died; cleaning up
[   71.073062] usb usb1-port1: attempt power cycle

I've tried adding/removing kmod-usb* modules, but nothing really changed. What could I be missing?

9

I must admit after a week of tuning attempts I could not resolve this issue. For the time being, I switched back to ar71xx build. The USB driver seems to be stable there.