Re: FYI: RPi* firmware tagged 1.20210805 *is* the last to be bootable by FreeBSD via fdt use; sequence of 2 failure modes after that

[1.20210805 works if I avoid deleting a file that I should
not have deleted.]

On 2022-Apr-27, at 23:47, Mark Millard <[email protected]> wrote:

> [Just an FYI: I got ahold of the RPi3B and discovered that
> it was not bootable via RPi* firmware tagged 1.20210805 .

Turns out I had deleted a required firmware file
from 1.20210805 without noticing. I finally noticed
that I'd done so after ending up with a 1.20210727
also did not work in the RPi3B --for the same
stupid-operator-error reason.

> . . . (junk text removed) . . .
> 
> [I've not added to the below and have removed the long text
> block of RPi4B boot failure output.]
> 
> On 2022-Apr-24, at 05:36, Mark Millard <[email protected]> wrote:
> 
>> [I may have also found what leads to the extra messages for
>> the 2nd failure mode, an independent issue it turns out.]
>> 
>> On 2022-Apr-24, at 04:37, Mark Millard <[email protected]> wrote:
>> 
>>> [I think I found the reason for the boot crash that is
>>> a common failure to both failure modes. The 2nd mode
>>> has other issues I've not analyzed.]
>>> 
>>> On 2022-Apr-23, at 23:45, Mark Millard <[email protected]> wrote:
>>> 
>>>> The following is based on a microsd card with 13.1-RC4 on
>>>> it were I'd previously substituted my U-Boot 2022.04 build
>>>> and tested with the RPi* firmware that is in the 13.1-RC4
>>>> image. Here I've tried replacing the RPi* firmware and
>>>> holding the rest constant.
>>>> 
>>>> The boot tests are on a 8 GiByte RPi4B Rev 1.14 with the
>>>> B0T stepping. I've not been copying over the linux kernels,
>>>> which they also bundle with the firmware.
>>>> 
>>>> [13.1-RC4 is just what I happened to use. I doubt anything
>>>> here is special to 13.* or stable/13 or main [so: 14].
>>>> (I do not use 12.* or stable/12.)]
>>>> 
>>>> The observed status went like . . .
>>>> 
>>>> 
>>>> firmware-1.20210805/boot/
>>>> 
>>>> The RPi* release tagged 1.20210805 is the last version that
>>>> FreeBSD booted with. (Other than booting, logging in, and
>>>> shutting down, I've not been testing other aspects of
>>>> operation.)
>>>> 
>>>> From what I've read, firmware-1.20210805/boot/ should be
>>>> recent enough to handle the Rev 1.15 related PMIC variation.
>>>> 
>>>> [I'll note that firmware build dates need not be the same day
>>>> as the date encoded into the tag --in fact it is usually some
>>>> earlier day. On rare occasion it can be a lot earlier, and
>>>> there is an example of that below.]
>>>> 
>>>> 
>>>> After firmware-1.20210805 there are 2 major failure modes.
>>>> Both stop at the same sort of point in the messaging --but
>>>> there is a huge difference in the count of earlier error
>>>> messages. It looks to me like all the issues require
>>>> FreeBSD changes if modern RPi* firmware/dtb's are to be
>>>> usable via fdt.
>>> 
>>> I've noticed a difference between the working context and
>>> the failing ones (both failure modes).
>>> 
>>> Failing:
>>> 
>>> spi0: <BCM2708/2835 SPI controller> mem 0x7e204000-0x7e2041ff irq 18 on simplebus0
>>> spibus0: <OFW SPI bus> on spi0
>>> spibus0: <unknown card> at cs 0 mode 0
>>> spibus0: <unknown card> at cs 1 mode 0
>>> NOTE BELOW LINES MISSING HERE.
>>> sdhci_bcm0: <Broadcom 2708 SDHCI controller> mem 0x7e300000-0x7e3000ff irq 24 on simplebus0
>>> 
>>> Working:
>>> 
>>> spi0: <BCM2708/2835 SPI controller> mem 0x7e204000-0x7e2041ff irq 18 on simplebus0
>>> spibus0: <OFW SPI bus> on spi0
>>> spibus0: <unknown card> at cs 0 mode 0
>>> spibus0: <unknown card> at cs 1 mode 0
>>> START LINES MISSING ABOVE
>>> iichb0: <BCM2708/2835 BSC controller> mem 0x7e804000-0x7e804fff irq 26 on simplebus0
>>> bcm_dma0: <BCM2835 DMA Controller> mem 0x7e007000-0x7e007aff irq 30,31,32,33,34,35,36,37,38,39,40 on simplebus0
>>> bcmwd0: <BCM2708/2835 Watchdog> mem 0x7e100000-0x7e100113,0x7e00a000-0x7e00a023,0x7ec11000-0x7ec1101f on simplebus0
>>> bcmrng0: <Broadcom BCM2835/BCM2838 RNG> mem 0x7e104000-0x7e104027 on simplebus0
>>> gpioc1: <GPIO controller> on gpio1
>>> END LINES MISSING ABOVE
>>> sdhci_bcm0: <Broadcom 2708 SDHCI controller> mem 0x7e300000-0x7e3000ff irq 73 on simplebus0
>>> 
>>> In particular:
>>> 
>>> bcm_dma0: <BCM2835 DMA Controller> mem 0x7e007000-0x7e007aff irq 30,31,32,33,34,35,36,37,38,39,40 on simplebus0
>>> 
>>> being missing means no bcm_dma_attach and that in turn means
>>> that the static bcm_dma_sc == NULL still.
>>> 
>>> The panic was: panic: vm_fault failed: ffff000000862134
>>> 
>>> where:
>>> 
>>> ffff000000862134 <bcm_dma_allocate+0x88> ldaxr  x1, [x9]
>>> 
>>> which is part of:
>>> 
>>> int
>>> bcm_dma_allocate(int req_ch)
>>> {
>>>      struct bcm_dma_softc *sc = bcm_dma_sc;
>>>      int ch = BCM_DMA_CH_INVALID;
>>>      int i;
>>> 
>>>      if (req_ch >= BCM_DMA_CH_MAX)
>>>              return (BCM_DMA_CH_INVALID);
>>> 
>>>      /* Auto(req_ch < 0) or CH specified */
>>>      mtx_lock(&sc->sc_mtx);
>>> . . .
>>> 
>>> So the likes of &sc->sc_mtx end up being a small offset
>>> from address zero:
>>> 
>>> x9:               20
>>> 
>>> Thus the panic.
>>> 
>>> As to how bcm_dma_allocate happened without bcm_dma_attach
>>> happening first . . .
>>> 
>>> The working context's dtb has the ordering:
>>> (I also show mmcnr@ and the brcm,bcm2711-dma
>>> just for reference.)
>>> 
>>>              dma@7e007000 {
>>>                      compatible = "brcm,bcm2835-dma";
>>> . . .
>>>              mmc@7e300000 {
>>>                      compatible = "brcm,bcm2835-mmc", "brcm,bcm2835-sdhci";
>>> . . .
>>>              mmcnr@7e300000 {
>>>                      compatible = "brcm,bcm2835-mmc", "brcm,bcm2835-sdhci";
>>> . . .
>>>              dma@7e007b00 {
>>>                      compatible = "brcm,bcm2711-dma";
>>> 
>>> But the failing context's dtb has the ordering:
>>> (I also show mmcnr@ and the brcm,bcm2711-dma
>>> just for reference.)
>>> 
>>>              mmc@7e300000 {
>>>                      compatible = "brcm,bcm2835-mmc", "brcm,bcm2835-sdhci";
>>> . . .
>>>              dma@7e007000 {
>>>                      compatible = "brcm,bcm2835-dma";
>>> . . .
>>>              mmcnr@7e300000 {
>>>                      compatible = "brcm,bcm2835-mmc", "brcm,bcm2835-sdhci";
>>> . . .
>>>              dma@7e007b00 {
>>>                      compatible = "brcm,bcm2711-dma";
>>> 
>>> So, for sequential handling in the failing case, the dma@7e007000
>>> would use bcm_dma_allocate before the bcm_dma_probe/bcm_dma_attach
>>> sequence had happened, leading to the crash.
>>> 
>>> Note: I used "fdt print /" from U-Boot to get the dtb and its
>>> ordering. This was based on the address that the RPi* firmware
>>> reports when debugging output is enabled (0x4000 here).
>>> 
>>> 
>>>> The 1st mode happens for (I've added the -fails notation):
>>>> 
>>>> firmware-1.20210831-fails/boot/
>>>> firmware-1.20210928-fails/boot/
>>>> firmware-1.20211007-fails/boot/
>>>> firmware-1.20211029-fails/boot/
>>>> firmware-1.20211118-fails/boot/
>>>> firmware-1.20220308_buster-fails/boot/
>>>> (The _buster one has firmware from 2021-Dec-01, which
>>>> is before all the tagged releases listed below.
>>>> It looks like the switch to the new major kernel
>>>> version after buster came with other changes that
>>>> FreeBSD has not tracked.)
>>>> 
>>>> 
>>>> The 2nd mode happens for the following. (Again with extra
>>>> notation.) There are a lot more error messages before the
>>>> panic happens for these. The firmware builds for these
>>>> are more recent than for the above list.
>>>> 
>>>> 
>>>> firmware-1.20220118-fails/boot/
>>>> 
>>>> firmware-1.20220120-fails/boot/
>>>> firmware-1.20220308-fails-non-kernels-same-as-1.20220120/boot/
>>>> (I did not repeat the testing of the unchanged firmware.
>>>> I just did the "diff -r" to discover the lack of change.)
>>>> 
>>>> firmware-1.20220328-fails/boot/
>>>> firmware-1.20220331-fails-non-kernels-same-as-firmware-1.20220328-but-for-bcm2711-dtb-files/boot/
>>>> (Since the .dtb for the RPi4B was different, I did test this.)
>> 
>> It looks like the extra messages, blocks of:
>> 
>> clk_fixed4: <Fixed clock> disabled on ofwbus0
>> clk_fixed4: Cannot FDT parameters.
>> device_attach: clk_fixed4 attach returned 6
>> 
>> Are tied to new dtb content in 2022's dtb updates:
>> 
>>       cam1_clk {
>>               compatible = "fixed-clock";
>>               #clock-cells = <0x00000000>;
>>               status = "disabled";
>>               phandle = <0x000000e2>;
>>       };
>> . . .
>>       cam0_clk {
>>               compatible = "fixed-clock";
>>               #clock-cells = <0x00000000>;
>>               status = "disabled";
>>               phandle = <0x000000e4>;
>>       };
>> 
>> These 2 did not exist back when the 1st failure mode
>> started. They appear to be repeatedly processed from
>> not really being handled --leading to lots of
>> messages.
>> 
>> The messages may just be noise for activity that is
>> not contributing to boot failures at all. So fixing
>> what I called the 1st failure mode might actually fix
>> booting for all the firmware versions after the
>> version tagged 1.20210805 .
>> 
>>>> The failures look like (each test shown) . . .
>>>> 
>>>> 
>>>> . . .
>>> 
> 


===
Mark Millard
marklmi at yahoo.com