Re: [RFC PATCH v2 00/14] hw/arm: add TI AM64x SoC and am64-virt machine

On 2026-08-22 13:22, Bin Meng wrote:

> Hi Wadim,
>
> On Thu, Aug 20, 2026 at 8:48 PM Wadim Mueller <[email protected]> wrote:
>>
>> Add support for the TI AM64x (Sitara AM6442) SoC and a board around it,
>> ``am64-virt``. The model is complete enough to run the stock TI boot chain
>> end to end:
>
> Should the machine be named as something that matches an existing
> board from TI, instead of `am64-virt`, which makes me think it's just
> something we created just for emulation purpose?
>

Yeah, the name is misleading, and it also undersells what is
there.

The SoC side is not really virt-like: it is the real AM64x memory map,
GICv3 at the silicon addresses, the real UART / I2C / timer /
secure-proxy offsets, and it boots stock unmodified vendor firmware
through the complete chain ROM -> R5 SPL -> TF-A/OP-TEE -> U-Boot ->
Linux.

What I did not mention in the cover letter is that my development tree
already models the board identity as well: an M24C32 at i3c address 0x50,
preloaded with a valid PHYTEC api-v2 identity blob
with the correct size and CRC so that
mainline u-boot's accepts it. This is what the vendor
U-Boot reads to detect the SoM. I left it out of v2 because I was not
sure if board specific identity data is wanted upstream, but I think
now this was the wrong decision, because it is exactly the proof that
this is a board model and not something synthetic.

So IMHO the options are:

  a) am64-phycore, which matches the phyCORE-AM64x SoM that I boot and
     test every day, and the identity EEPROM moves from the SoC model
     into the board file, where it belongs anyway
  b) am64-evm or am64-sk, after TMDS64GPEVM or SK-AM64B, which means
     doing the board identity again against TI's EEPROM format and
     getting that firmware

I would prefer a), because this is the configuration I have hardware
for and which I can keep testing for regressions, so the maintenance
story is realistic.

One caveat: not every peripheral is modelled. CPSW
is only an unimplemented-device stub and there is no ethernet node in
the DT. For booting this does not matter, because the whole chain runs
from SD/eMMC, but a machine with a board name should probably document
what is there and what is not. docs/system/arm/am64.rst does this
already, and in v3 I will make the name and the documented scope match.

So my question back: does a non-TI board around the SoC (a SoM from
PHYTEC) fulfill your "matches an existing board", or would you rather
see a TI branded one?

Best regards,
Wadim


>>
>>   ROM boot (tiboot3.bin) -> R5 SPL -> TF-A/OP-TEE -> U-Boot -> Linux SMP
>>
>> This is a resend: I posted a first RFC back in May [1] but got no feedback
>> on it. Since then was the series rebased onto actual master, reworked for
>> style and split into reviewable pieces, so I send it out again in the hope
>> of getting some review.
>>
>> RFC because I would like feedback on the overall approach before polishing
>> further; see the open questions at the end.
>>
>> [1] https://lore.kernel.org/qemu-devel/[email protected]/
>>
>> What is modelled
>> ================
>>
>> The SoC is heterogeneous, and the model reflects that: a Cortex-A53
>> cluster behind a GICv3 (GIC-500) at the real addresses, the Cortex-R5F
>> MCU boot core, and the Cortex-M4F, each with their own RAT (region
>> address translation) view of the memory map.
>>
>> The interesting part is the DMSC. On real silicon it is a hidden core
>> running TI's system firmware (SYSFW) which answers TI-SCI requests for
>> clocks, power, firewalls and processor boot control from every other core.
>> Rather than trying to execute the vendor blob, patch 10 models the DMSC
>> as a TI-SCI endpoint sitting on top of the secure proxy model (patch 9).
>> That is what actually starts the A53 and M4F cores when the R5 SPL asks
>> for it, and what TF-A, OP-TEE, U-Boot and Linux talk to for clock/power
>> management.
>>
>> The remaining devices (patches 4-8) are the supporting cast: the UART,
>> the K3 DMTimer, mailboxes, and register-level stubs for CTRL_MMR
>> (including the DEVSTAT boot pins), GTC, DDRSS, the SDHCI PHY wrapper and
>> the TRNG. The
>> stubs implement the handshakes, which firmware polls for, not the
>> underlying hardware.
>>
>> Patches 1-3 are prerequisites that touch existing code:
>>
>>   1-2  give the OMAP I2C model its own Kconfig symbol so it can be reused
>>        outside the OMAP1 SoC, and implement soft reset and NACK reporting
>>   3    fixes SDHCI ADMA chain processing; without it, transfer rate
>>        depends from the virtual clock instead of on the guest's
>>        programming. Patch 14 contains a qtest that fails without it.
>>
>> To patch 3: it is only needed as long as Bin Meng's SDHCI series [2] (on
>> top of the SDMA boundary fix [3]) is not merged. I posted the same fix
>> standalone in August, Bin showed then, that his series already covers
>> the AM64x case, and I have withdrawn it there [4]. It is kept here only
>> so that this series works on actual master - please drop patch 3
>> together with the pacing qtest in patch 14 as soon as [2] lands. A
>> version of that qtest for the Icicle Kit was posted separately [5].
>>
>> [2] https://patchwork.ozlabs.org/project/qemu-devel/list/?series=515264
>> [3] https://patchwork.ozlabs.org/project/qemu-devel/list/?series=513930
>> [4] https://lore.kernel.org/qemu-devel/[email protected]/
>> [5] https://lore.kernel.org/qemu-devel/[email protected]/
>>
>> Testing
>> =======
>>
>> Patch 14 adds:
>>
>>   * a unit test for the combined-boot-image parser
>>   * qtests for the machine topology, GICv3 layout, SMP handling and the
>>     DMSC TI-SCI request/response path
>>   * an I2C qtest (soft reset, NACK, and a read from an at24c EEPROM which
>>     the test attaches with -device)
>>   * the SDHCI ADMA pacing reproducer
>>   * a functional test that builds a synthetic tiboot3.bin containing a
>>     bare-metal R5 payload and checks it runs from the certified entry
>>     point. Setting QEMU_TEST_TIBOOT3 boots a real image instead.
>>
>> Migration is not supported yet: none of the new devices has a VMState.
>> I left it out for the RFC, but can add it if you want it before merge.
>>
>> The series was built and tested on top of ae4f344320. Every patch builds
>> on its own, and checkpatch reports no errors.
>>
>> Open questions
>> ==============
>>
>>   * pc-bios/dtb/am64-virt.dtb: patch 13 checks in a generated DTB (with
>>     its source) for convenience. I am not sure a machine-specific blob
>>     belongs in pc-bios; happy to drop it and have the functional test
>>     generate it with dtc instead, or drop the Linux-boot part of the test.
>>
>>   * Splitting the DMSC: hw/misc/ti-dmsc.c is large because TI-SCI is
>>     large. It could be split per message class (clocks / devices /
>>     processor boot / security) if reviewers prefer, at the cost of a
>>     non-functional intermediate state.
>>
>>   * Only one of the four R5F cores is modelled. mc->max_cpus reserves
>>     room for the rest. Because the SoC realizes M4F/R5F vCPUs in addition
>>     to the A53s and every vCPU needs a TCG context slot inside
>>     smp.max_cpus, the machine defaults to the full vCPU budget. I would
>>     appreciate a better idea than the actual "fail early with an
>>     explanatory message" handling when the user passes a too-small -smp.
>>
>>   * The register-level stubs (DDRSS in particular) fake success rather
>>     than modelling the hardware. That is deliberate, but tell me if you
>>     would rather see them as plain unimplemented-device windows plus
>>     firmware quirks elsewhere.
>>
>> Wadim Mueller (14):
>>   hw/i2c/omap_i2c: add a dedicated CONFIG_OMAP_I2C symbol
>>   hw/i2c/omap_i2c: implement soft reset and NACK reporting
>>   hw/sd/sdhci: complete non-interrupt ADMA descriptor chains in one pass
>>   hw/char: add TI AM64x UART model
>>   hw/timer: add TI K3 DMTimer model
>>   hw/misc: add TI K3 CTRL_MMR, GTC, DDRSS, SDHCI PHY and TRNG models
>>   hw/misc: add TI RAT (region address translation) model
>>   hw/misc: add TI mailbox (IPC) model
>>   hw/misc: add TI K3 secure proxy model
>>   hw/misc: add TI DMSC (TI-SCI system controller) model
>>   hw/arm: add TI K3 combined boot image parser
>>   hw/arm: add TI AM64x SoC model
>>   hw/arm: add the am64-virt machine
>>   tests: add AM64x unit, qtest and functional tests
>>
>>  MAINTAINERS                                   |   22 +
>>  docs/system/arm/am64.rst                      |   74 +
>>  docs/system/target-arm.rst                    |    1 +
>>  hw/arm/Kconfig                                |   26 +
>>  hw/arm/am64-virt.c                            |  347 ++++
>>  hw/arm/k3-bootrom-parse.c                     |  250 +++
>>  hw/arm/k3-bootrom.c                           |  125 ++
>>  hw/arm/meson.build                            |    4 +
>>  hw/arm/ti-am64x.c                             | 1223 ++++++++++++
>>  hw/arm/trace-events                           |    4 +
>>  hw/char/Kconfig                               |    4 +
>>  hw/char/meson.build                           |    1 +
>>  hw/char/ti-am64-uart.c                        |  109 ++
>>  hw/i2c/Kconfig                                |    4 +
>>  hw/i2c/meson.build                            |    2 +-
>>  hw/i2c/omap_i2c.c                             |  234 ++-
>>  hw/misc/Kconfig                               |   27 +
>>  hw/misc/meson.build                           |   10 +
>>  hw/misc/ti-dmsc.c                             | 1725 +++++++++++++++++
>>  hw/misc/ti-k3-ctrlmmr.c                       |  103 +
>>  hw/misc/ti-k3-ddrss.c                         |   98 +
>>  hw/misc/ti-k3-gtc.c                           |  100 +
>>  hw/misc/ti-k3-sdhci-phy.c                     |   91 +
>>  hw/misc/ti-k3-trng.c                          |  139 ++
>>  hw/misc/ti-mailbox.c                          |  566 ++++++
>>  hw/misc/ti-rat.c                              |  290 +++
>>  hw/misc/ti-sec-proxy.c                        |  446 +++++
>>  hw/misc/trace-events                          |   62 +
>>  hw/sd/sdhci-internal.h                        |    9 +
>>  hw/sd/sdhci.c                                 |   23 +-
>>  hw/timer/Kconfig                              |    3 +
>>  hw/timer/meson.build                          |    1 +
>>  hw/timer/ti-k3-dmtimer.c                      |  177 ++
>>  include/hw/arm/k3-bootrom.h                   |   43 +
>>  include/hw/arm/ti-am64x.h                     |   86 +
>>  include/hw/char/ti-am64-uart.h                |   28 +
>>  include/hw/misc/ti-dmsc.h                     |  661 +++++++
>>  include/hw/misc/ti-k3-ctrlmmr.h               |   26 +
>>  include/hw/misc/ti-k3-ddrss.h                 |   26 +
>>  include/hw/misc/ti-k3-gtc.h                   |   23 +
>>  include/hw/misc/ti-k3-sdhci-phy.h             |   26 +
>>  include/hw/misc/ti-k3-trng.h                  |   35 +
>>  include/hw/misc/ti-mailbox.h                  |   44 +
>>  include/hw/misc/ti-rat.h                      |   51 +
>>  include/hw/misc/ti-sec-proxy.h                |  108 ++
>>  include/hw/timer/ti-k3-dmtimer.h              |   30 +
>>  pc-bios/dtb/am64-virt.dtb                     |  Bin 0 -> 6116 bytes
>>  pc-bios/dtb/am64-virt.dts                     |  292 +++
>>  tests/functional/aarch64/meson.build          |    2 +
>>  tests/functional/aarch64/test_am64_bootrom.py |  137 ++
>>  tests/qtest/am64-adma-pacing-test.c           |  243 +++
>>  tests/qtest/am64-virt-test.c                  |  502 +++++
>>  tests/qtest/meson.build                       |    1 +
>>  tests/qtest/ti-am64-i2c-test.c                |  137 ++
>>  tests/unit/meson.build                        |    1 +
>>  tests/unit/test-k3-bootrom.c                  |  263 +++
>>  56 files changed, 9060 insertions(+), 5 deletions(-)
>>  create mode 100644 docs/system/arm/am64.rst
>>  create mode 100644 hw/arm/am64-virt.c
>>  create mode 100644 hw/arm/k3-bootrom-parse.c
>>  create mode 100644 hw/arm/k3-bootrom.c
>>  create mode 100644 hw/arm/ti-am64x.c
>>  create mode 100644 hw/char/ti-am64-uart.c
>>  create mode 100644 hw/misc/ti-dmsc.c
>>  create mode 100644 hw/misc/ti-k3-ctrlmmr.c
>>  create mode 100644 hw/misc/ti-k3-ddrss.c
>>  create mode 100644 hw/misc/ti-k3-gtc.c
>>  create mode 100644 hw/misc/ti-k3-sdhci-phy.c
>>  create mode 100644 hw/misc/ti-k3-trng.c
>>  create mode 100644 hw/misc/ti-mailbox.c
>>  create mode 100644 hw/misc/ti-rat.c
>>  create mode 100644 hw/misc/ti-sec-proxy.c
>>  create mode 100644 hw/timer/ti-k3-dmtimer.c
>>  create mode 100644 include/hw/arm/k3-bootrom.h
>>  create mode 100644 include/hw/arm/ti-am64x.h
>>  create mode 100644 include/hw/char/ti-am64-uart.h
>>  create mode 100644 include/hw/misc/ti-dmsc.h
>>  create mode 100644 include/hw/misc/ti-k3-ctrlmmr.h
>>  create mode 100644 include/hw/misc/ti-k3-ddrss.h
>>  create mode 100644 include/hw/misc/ti-k3-gtc.h
>>  create mode 100644 include/hw/misc/ti-k3-sdhci-phy.h
>>  create mode 100644 include/hw/misc/ti-k3-trng.h
>>  create mode 100644 include/hw/misc/ti-mailbox.h
>>  create mode 100644 include/hw/misc/ti-rat.h
>>  create mode 100644 include/hw/misc/ti-sec-proxy.h
>>  create mode 100644 include/hw/timer/ti-k3-dmtimer.h
>>  create mode 100644 pc-bios/dtb/am64-virt.dtb
>>  create mode 100644 pc-bios/dtb/am64-virt.dts
>>  create mode 100644 tests/functional/aarch64/test_am64_bootrom.py
>>  create mode 100644 tests/qtest/am64-adma-pacing-test.c
>>  create mode 100644 tests/qtest/am64-virt-test.c
>>  create mode 100644 tests/qtest/ti-am64-i2c-test.c
>>  create mode 100644 tests/unit/test-k3-bootrom.c
>>
>>
>> base-commit: ae4f3443209ab154b48b706a146e5f557ab147cb
>
> Regards,
> Bin