Extracting (boardvendor and) boardtype

Rafał Miłecki zajec5 at gmail.com
Tue Mar 19 07:37:55 EDT 2013

2013/3/19 Arend van Spriel <arend at broadcom.com>:
> On 03/19/2013 12:18 PM, Rafał Miłecki wrote:
>> 2013/3/19 Jonas Gorski <jogo at openwrt.org>:
>>> On 19 March 2013 11:36, Rafał Miłecki <zajec5 at gmail.com> wrote:
>>>> However take a look at siutils.c you're using internally at Broadcom.
>>>> I've found it in:
>>>> GPL_RT_AC66U_3004270/asuswrt/release/src-rt-6.x/shared/siutils.c
>>>> This file contains si_nvram_process. This function calls that
>>>> si_getdevpathintvar and getintvar I'm not sure about. Does
>>>> si_nvram_process prefer SPROM's boardtype (offset SROM_SSID==0x2 or
>>>> offset SSB_SPROM1_SPID==0x4) if it's available (not 0xFFFF)?
>>> The getdevpathintvar and getintvar are for extracting these values
>>> from nvram instead of SPROM - remember that embedded bcm47xx devices
>>> are "sprom"-less and have these values stored in nvram. Since there is
>>> only one global nvram, you need to prefix these values with the
>>> "pci/sb" device path to differentiate if you have more than one wifi
>>> chip (e.g. "sb/1/boardflags" or "pci/1/boardflags"). But this isn't
>>> necessarily done for single wifi devices, hence the getdevpathintvar
>>> -> getinvar path (as the fall back).
>> So what function does Broadcom use to extract something from SPROM?
> srom_var_init()

OK, so for PCI:
1) srom_var_init calls initvars_srom_pci
2) initvars_srom_pci calls _initvars_srom_pci
3) _initvars_srom_pci calls varbuf_append for every entry

After all we end up with varbuf_t variable filled like an NVRAM

So AFAIU getdevpathintvar and getintvar are still used to access SPROM
(just in a form common for NVRAM), is that right?

If the above is right, in si_nvram_process we access SPROM (with the
use of getdevpathintvar/getintvar). So it seems in si_nvram_process we
always prefer "boardtype", no matter if it comes from SPROM of NVRAM.
Is that correct?


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