On 11:23 Mon 25 Mar , Douglas Gilbert wrote: > On 13-03-25 10:31 AM, Jean-Christophe PLAGNIOL-VILLARD wrote: > >On 09:48 Mon 25 Mar , Douglas Gilbert wrote: > >>On 13-03-25 08:22 AM, Jean-Christophe PLAGNIOL-VILLARD wrote: > >>>On 09:49 Mon 25 Mar , Nicolas Ferre wrote: > >>>>From: Douglas Gilbert <[email protected]> > >>>> > >>>>Signed-off-by: Douglas Gilbert <[email protected]> > >>>>Signed-off-by: Nicolas Ferre <[email protected]> > >>>>--- > >>>> arch/arm/boot/dts/ariag25.dts | 168 > >>>> ++++++++++++++++++++++++++++++++++++++++++ > >>>> 1 file changed, 168 insertions(+) > >>>> create mode 100644 arch/arm/boot/dts/ariag25.dts > >>>> > >>>>diff --git a/arch/arm/boot/dts/ariag25.dts b/arch/arm/boot/dts/ariag25.dts > >>>>new file mode 100644 > >>>>index 0000000..d18ef50 > >>>>--- /dev/null > >>>>+++ b/arch/arm/boot/dts/ariag25.dts > >>>>@@ -0,0 +1,168 @@ > >>>>+/* > >>>>+ * ariag25.dts - Device Tree file for Acme Systems Aria G25 (AT91SAM9G25 > >>>>based) > >>>>+ * > >>>>+ * Copyright (C) 2013 Douglas Gilbert <[email protected]>, > >>>>+ * Robert Nelson <[email protected]> > >>>>+ * > >>>>+ * Licensed under GPLv2 or later. > >>>>+ */ > >>>>+/dts-v1/; > >>>>+/include/ "at91sam9g25.dtsi" > >>>>+ > >>>>+/ { > >>>>+ model = "Acme Systems Aria G25"; > >>>>+ compatible = "acme,ariag25", "atmel,at91sam9g25ek", > >>>>"atmel,at91sam9x5ek", > >>>>+ "atmel,at91sam9x5", "atmel,at91sam9"; > >>>I doube the code is compatible with the 9g25ek > >>> > >>>specially when you do not include it > >>>>+ > >>>>+ aliases { > >>>>+ serial4 = &usart3; > >>>>+ serial5 = &uart0; > >>>>+ }; > >>>you need to specify all > >>>>+ > >>>>+ chosen { > >>>>+ bootargs = "console=ttyS0,115200 root=/dev/mmcblk0p2 rw > >>>>rootwait"; > >>>>+ }; > >>>>+ > >>>>+ memory { > >>>>+ /* 128 MB, change this for 256 MB revision */ > >>>>+ reg = <0x20000000 0x8000000>; > >>>>+ }; > >>>>+ > >>>>+ clocks { > >>>>+ #address-cells = <1>; > >>>>+ #size-cells = <1>; > >>>>+ ranges; > >>>>+ > >>>>+ main_clock: clock@0 { > >>>>+ compatible = "atmel,osc", "fixed-clock"; > >>>>+ clock-frequency = <12000000>; > >>>>+ }; > >>>>+ }; > >>>>+ > >>>>+ ahb { > >>>>+ apb { > >>>>+ mmc0: mmc@f0008000 { > >>>>+ /* N.B. Aria has no SD card detect (CD), > >>>>assumed present */ > >>>>+ > >>>>+ pinctrl-0 = < > >>>>+ &pinctrl_mmc0_slot0_clk_cmd_dat0 > >>>>+ &pinctrl_mmc0_slot0_dat1_3>; > >>>>+ status = "okay"; > >>>>+ slot@0 { > >>>>+ reg = <0>; > >>>>+ bus-width = <4>; > >>>>+ }; > >>>>+ }; > >>>>+ > >>>>+ i2c0: i2c@f8010000 { > >>>>+ status = "okay"; > >>>>+ }; > >>>>+ > >>>>+ i2c1: i2c@f8014000 { > >>>>+ status = "okay"; > >>>>+ }; > >>>>+ > >>>>+ /* TWD2+TCLK2 hidden behind ethernet, so no i2c2 */ > >>>>+ > >>>>+ usart0: serial@f801c000 { > >>>>+ pinctrl-0 = <&pinctrl_usart0 > >>>>+ &pinctrl_usart0_rts > >>>>+ &pinctrl_usart0_cts>; > >>>>+ status = "okay"; > >>>>+ }; > >>>>+ > >>>>+ usart1: serial@f8020000 { > >>>>+ pinctrl-0 = <&pinctrl_usart1 > >>>>+ /* &pinctrl_usart1_rts */ > >>>>+ /* &pinctrl_usart1_cts */ > >>>>+ >; > >>>>+ status = "okay"; > >>>>+ }; > >>>>+ > >>>>+ usart2: serial@f8024000 { > >>>>+ /* cannot activate RTS2+CTS2, clash with > >>>>+ * ethernet on PB0 and PB1 */ > >>>>+ pinctrl-0 = <&pinctrl_usart2>; > >>>>+ status = "okay"; > >>>>+ }; > >>>>+ > >>>>+ usart3: serial@f8028000 { > >>>>+ compatible = "atmel,at91sam9260-usart"; > >>>>+ reg = <0xf8028000 0x200>; > >>>>+ interrupts = <8 4 5>; > >>>>+ pinctrl-names = "default"; > >>>>+ pinctrl-0 = <&pinctrl_usart3 > >>>>+ /* &pinctrl_usart3_rts */ > >>>>+ /* &pinctrl_usart3_cts */ > >>>>+ >; > >>>>+ status = "okay"; > >>>>+ }; > >>>>+ > >>>>+ macb0: ethernet@f802c000 { > >>>>+ phy-mode = "rmii"; > >>>>+ /* following can be overwritten by uboot 'ftd > >>>>set' command */ > >>>>+ local-mac-address = [00 04 25 dd 10 01]; > >>>drop this, this is board specific > >>>>+ status = "okay"; > >> > >>Also the local-mac-address line is needed since it is edited > >>by u-boot via this line: > >> > >>mod_dtb=fdt addr 0x27FF0000 ; fdt set ${eth0_dt_path} > >>local-mac-address [ ${my_ethaddr} ] > >> > >>Interesting technique that: editing the dtb from u-boot prior to the > >>Linux kernel using it ... > >> > >>So the u-boot environment file actually sets the MAC address. The Aria > >>G25 has no NAND, flash or switches for setting a quasi unique MAC > >>address. There seems to be no way to pass the MAC address on the > >>kernel boot line (there was in the past). That leaves the microSD card > >>and IMO u-boot is the best place to set that MAC address. My guess > >>is that the Aria G25 is not the only board that has this "setting the > >>MAC address" challenge. > >> > >>Finally of course that line is "board specific", that is why the > >>file is called ariag25.dts :-) > >The mac address is board (hw) uniq so no default in the dts, if none present > >the kernel will generate one (private class). > > Since when have MAC addresses been hw uniq? since EVER this is why you can resolve the IP <=> MAC on public network That's why when you buy a mac address range, you need to prouve how you handle it to buy a second range.
> My guess is > a huge majority of MAC addresses are set in firmware. > Since many embedded systems with wired ethernet face > this problem, is it the job of Linux to make this more > difficult than it already is? yes but NEVER set the same mac address for every board (hw) in a DT or in C > > >If the mac is specifued in the register the kernel re-use it. > > Unless u-boot (or whatever) edits the dtb file before the > Linux kernel sees it. > > >This is the job of the booloader to set one. The dts in the kernel will be > >used for every Aria not one board in particular > > It is the job of someone to set it. A MAC address can be > compiled into u-boot but that is about as useful as > compiling it into Linux kernel. no default one in the kernel dt on some server we flash a dtb with a mac inside but this handle at production level and the dts in the kernel does not have ANY default mac address > > >if you keep the mac addres in the dts NACK > > Seems strange to object to setting > local-mac-address = [00 00 00 00 00 00]; > when if the kernel sees that line it will do exactly the > same thing as without that line? But the advantage of that > line is that it gives the u-boot environment file the > ability to edit the ariag25.dtb before the kernel sees it. > And if the u-boot environment file is properly configured > by the board manufacturer, then a quasi uniq, stable MAC > address is generated. in you patch you put a mac address not 00 00 00 00 00 00 and if u-boot is not able to add a property fix it > > For more information about this technique see: > http://www.petalogix.com/support/kb/mac_addr_update I known how dt work and how to handle it at bootloader level for more than 6 years Best Regards, J. > > > Doug Gilbert > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
