Re: kwboot: Testing latest kwboot with Kirkwood SoC boards

[Tony Dinh <mibodhi@gmail.com>]

Hi Pali,

On Sat, Nov 6, 2021 at 3:57 AM Pali Rohár <pali@kernel.org> wrote:
>
> Hello!
>
> On Friday 05 November 2021 20:50:18 Tony Dinh wrote:
> > Hi Pali,
> >
> > On Fri, Nov 5, 2021 at 5:10 PM Pali Rohár <pali@kernel.org> wrote:
> > >
> > > On Friday 05 November 2021 16:36:47 Tony Dinh wrote:
> > > > Hi Pali,
> > > >
> > > > On Fri, Nov 5, 2021 at 3:15 PM Pali Rohár <pali@kernel.org> wrote:
> > > > >
> > > > > On Friday 05 November 2021 15:07:17 Tony Dinh wrote:
> > > > > > > > Also, I have several Kirkwood boards (with various old BootROM
> > > > > > > > versions) that I can run the kwboot tests on. Will keep you posted.
> > > > > > >
> > > > > > > Ok! Do you have some Kirkwood board with PCIe slot? If yes, I would like
> > > > > > > to see dumps from config space of Kirkwood PCIe Root Port, see:
> > > > > > > https://lore.kernel.org/u-boot/20211104154921.b6zxjpczj7t6qlct@pali/
> > > > > >
> > > > > > I have these Kirwood boards with PCI:
> > > > > > - No slot (host bus for USB 3.0): Pogoplug V4 (6192), Zyxel NSA325v2
> > > > > > (6282). These 2 boards can be kwboot.
> > > > > > - Iomega iConnect (6281), with PCIe slot for Wifi card. This board
> > > > > > does not have kwboot booting support.
> > > > >
> > > > > What do you mean that it 'does not have kwboot booting support'?
> > > > > 88F6281 is also Kirkwood and UART booting with kwboot should work.
> > > >
> > > > Most of the Kirkwood boards do have UART booting support. However, in
> > > > my past experience, some Kirkwood boxes did not work with kwboot
> > > > booting. It was observed experimentally that certain BootROM versions
> > > > (depending on the time of manufacturing) on the 88F6281 SoC have
> > > > problems with UART booting. But we have not proven this to be the real
> > > > reason. These boards failed UART booting (the behavior is like the
> > > > UART magic string handshake never occur):
> > > >
> > > > Seagate Dockstar (all), Iomega iConnect (all), Sheevaplug (some models
> > > > probably do work), Seagate GoFlex Net (most boxes work, but a few
> > > > models don't, and they have a different BootROM version from ones that
> > > > do work).
> > >
> > > Hmm... ok. Maybe some bootrom versions have broken UART booting.
> > >
> > > During experiment with A385 I observed that it is needed to send
> > > continuous stream of boot pattern without delay, so bootrom can properly
> > > detect it and enter UART booting. But after bootrom is in UART booting
> > > mode, it responds only when do not transmitting anything for some few
> > > milliseconds.
> > > So it is needed to solve two timing issues. First with upper bound (you
> > > cannot use large delay as bootrom does not detect boot pattern) and
> > > second with lower bound (you cannot use small delay as bootrom does not
> > > answer). Plus another issue that linux kernel does provide asynchronous
> > > tty API which could tell when output buffer was transmitted via UART.
> >
> > That's exactly what I've found trying to boot the Thecus N2350 (Armada
> > 385). I've tried various -q -s parameters but could not find the right
> > combination! OTOH, the Zyxel NAS326 (Armada 380) is OK with just the
> > default timing (still more work on my part in the u-boot image, but
> > kwboot started OK).
> >
> > >
> > > If some bootrom versions are too much timing sensitive and you do not
> > > know exact characteristic of it (and also of UART HW on the host) then
> > > it could be hard or impossible to enter that UART boot mode.
> >
> > I've always suspected the box UART HW is the reason for failure to
> > handshake, not the BootROM. But I'll try testing the old Kirkwood
> > boxes again with the new kwboot to be sure.
> >
> > > I'm planning to rewrite kwboot code which is sending boot pattern to be
> > > more precise on timings... So if you are interested in testing it, I
> > > could do it in a way with more configurable delays... once I would have
> > > some time for it.
> >
> > I'll be glad to test any new kwboot code you will have. My main
> > interest is the Armada 38x and all Kirkwood boards.
> >
> > >
> > > You could try to use tools/mrvl_uart.sh instead of kwboot. It implements
> > > also code for sending boot pattern. But it requires valid image with
> > > UART signature, it does not support on-the-fly patching like kwboot.
> >
> > That's what I did to boot the stock Thecus N2350 u-boot UART version.
> > An old version of this mrvl_uart.sh script has been on the net for
> > quite some time. But kwboot is more robust in the timing setup and
> > allows us to boot the final version that will be flashed.
>
> What could be interested is to try to use tools/mrvl_uart.sh script for
> booting those Kirkwood boards which was said that have broken UART
> booting. If tools/mrvl_uart.sh is able to trigger bootrom to switch to
> UART or not. Last version of tools/mrvl_uart.sh is still in U-Boot
> repository.

Good point. I will try that script to boot the iConnect and other boards.

>
> But as you said, kwboot is more robust and once kwboot would be to
> transfer all images which tools/mrvl_uart.sh is able then I send request
> to removal of tools/mrvl_uart.sh from U-Boot. As in U-Boot there is no
> need to have two different tools which implements same functionality.
>
> > > > > > I'll take a look at your link above and get back to you about the
> > > > > > config space dumps.
> > > > > >
> > > > > > By the way, I'm starting to look at the driver/pci/pci_mvebu.c to see
> > > > > > if it can be made to work with Kirkwood SoCs. I think there are many
> > > > > > differences in the addresses and memory space. I would appreciate it
> > > > > > if you have a general assessment whether I can use that driver for
> > > > > > Kirkwood.
> > > > >
> > > > > pci_mvebu.c should work with Kirkwood SoCs and also with all these
> > > > > 32-bit Marvell SoCs: Orion, Discovery, Kirkwood, Dove, A370, AXP, A375,
> > > > > A38x and A39x. According to Functional Specifications all these SoCs
> > > > > have common PCIe register set.
> > > >
> > > > That's great to hear!
> > > >
> > > > >
> > > > > If there is any issue with it, I could try to look at it.
> > > >
> > > > At the moment, pci_mvebu.c is not included in the build for Kirkwood
> > > > boards because ./drivers/pci/Kconfig excludes it:
> > > >
> > > > config PCI_MVEBU
> > > > bool "Enable Armada XP/38x PCIe driver"
> > > > depends on ARCH_MVEBU
> > > >
> > > > When I removed the above  dependency, the build had errors. Because
> > > > different soc.h and cpu.h are brought into pci_mvebu.c when
> > > > ARCH_KIRWOOD is enabled and ARCH_MVEBU is disabled.
> > > >
> > > > #include <asm/arch/cpu.h>
> > > > #include <asm/arch/soc.h>
> > >
> > > So, it it needed to do some adjustment of SoC related code and defines.
> > > I think the relevant parts are mapping of mbus windows.
> >
> > I did look a bit at the mbus windows. There are some differences from
> > MVEBU, such as in arch/arm/dts/kirkwood.dtsi
> >
> > pcie-mem-aperture = <0xe0000000 0x10000000>; /* 256 MiB memory space */
> > pcie-io-aperture  = <0xf2000000 0x100000>;   /*   1 MiB    I/O space */
> >
> > But my knowledge in PCI drivers is practically nothing, just hacking
> > it :) So if you plan to make this driver work for Kirkwood, I'd be
> > happy to volunteer to be a tester.
>
> I do not have Kirkwood hardware for testing. But it looks like that
> mach-kirkwood has just different names for mbus window constants.
>
> Here is simple (untested) patch which allows me to compile pci_mvebu.c
> for ARCH_KIRKWOOD:
>
> diff --git a/arch/arm/mach-kirkwood/cpu.c b/arch/arm/mach-kirkwood/cpu.c
> index e9571298a824..80f893ab369a 100644
> --- a/arch/arm/mach-kirkwood/cpu.c
> +++ b/arch/arm/mach-kirkwood/cpu.c
> @@ -54,11 +54,11 @@ unsigned int kw_winctrl_calcsize(unsigned int sizeval)
>
>  static struct mbus_win windows[] = {
>         /* Window 0: PCIE MEM address space */
> -       { KW_DEFADR_PCI_MEM, 1024 * 1024 * 256,
> +       { KW_DEFADR_PCI_MEM, KW_DEFADR_PCI_MEM_SIZE,
>           KWCPU_TARGET_PCIE, KWCPU_ATTR_PCIE_MEM },
>
>         /* Window 1: PCIE IO address space */
> -       { KW_DEFADR_PCI_IO, 1024 * 64,
> +       { KW_DEFADR_PCI_IO, KW_DEFADR_PCI_IO_SIZE,
>           KWCPU_TARGET_PCIE, KWCPU_ATTR_PCIE_IO },
>
>         /* Window 2: NAND Flash address space */
> diff --git a/arch/arm/mach-kirkwood/include/mach/cpu.h b/arch/arm/mach-kirkwood/include/mach/cpu.h
> index ea42182cf9c6..71c546f9acf6 100644
> --- a/arch/arm/mach-kirkwood/include/mach/cpu.h
> +++ b/arch/arm/mach-kirkwood/include/mach/cpu.h
> @@ -68,6 +68,9 @@ enum kwcpu_attrib {
>  #define KW_DEFADR_SPIF         0xE8000000
>  #define KW_DEFADR_BOOTROM      0xF8000000
>
> +#define KW_DEFADR_PCI_MEM_SIZE (1024 * 1024 * 256)
> +#define KW_DEFADR_PCI_IO_SIZE  (1024 * 64)
> +
>  struct mbus_win {
>         u32 base;
>         u32 size;
> diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
> index cc139af6cb57..71fac12257ad 100644
> --- a/drivers/pci/Kconfig
> +++ b/drivers/pci/Kconfig
> @@ -256,12 +256,12 @@ config PCIE_IPROC
>           Say Y here if you want to enable Broadcom iProc PCIe controller,
>
>  config PCI_MVEBU
> -       bool "Enable Armada XP/38x PCIe driver"
> -       depends on ARCH_MVEBU
> +       bool "Enable Kirkwood / Armada 370/XP/375/38x PCIe driver"
> +       depends on (ARCH_KIRKWOOD || ARCH_MVEBU)
>         select MISC
>         help
>           Say Y here if you want to enable PCIe controller support on
> -         Armada XP/38x SoCs.
> +         Kirkwood and Armada 370/XP/375/38x SoCs.
>
>  config PCIE_DW_COMMON
>         bool
> diff --git a/drivers/pci/pci_mvebu.c b/drivers/pci/pci_mvebu.c
> index c575e9412b2a..4cc8d2014052 100644
> --- a/drivers/pci/pci_mvebu.c
> +++ b/drivers/pci/pci_mvebu.c
> @@ -26,6 +26,14 @@
>  #include <linux/ioport.h>
>  #include <linux/mbus.h>
>
> +#ifdef CONFIG_ARCH_KIRKWOOD
> +#define SOC_REGS_PHY_BASE KW_REGS_PHY_BASE
> +#define MBUS_PCI_MEM_BASE KW_DEFADR_PCI_MEM
> +#define MBUS_PCI_IO_BASE KW_DEFADR_PCI_IO
> +#define MBUS_PCI_MEM_SIZE KW_DEFADR_PCI_MEM_SIZE
> +#define MBUS_PCI_IO_SIZE KW_DEFADR_PCI_IO_SIZE
> +#endif
> +
>  DECLARE_GLOBAL_DATA_PTR;
>
>  /* PCIe unit register offsets */
> @@ -97,7 +105,6 @@ struct mvebu_pcie {
>   * and 64K of I/O space when registered.
>   */
>  static void __iomem *mvebu_pcie_membase = (void __iomem *)MBUS_PCI_MEM_BASE;
> -#define PCIE_MEM_SIZE  (128 << 20)
>  static void __iomem *mvebu_pcie_iobase = (void __iomem *)MBUS_PCI_IO_BASE;
>
>  static inline bool mvebu_pcie_link_up(struct mvebu_pcie *pcie)
> @@ -433,14 +440,14 @@ static int mvebu_pcie_probe(struct udevice *dev)
>         mvebu_pcie_set_local_dev_nr(pcie, 1);
>
>         pcie->mem.start = (u32)mvebu_pcie_membase;
> -       pcie->mem.end = pcie->mem.start + PCIE_MEM_SIZE - 1;
> -       mvebu_pcie_membase += PCIE_MEM_SIZE;
> +       pcie->mem.end = pcie->mem.start + MBUS_PCI_MEM_SIZE - 1;
> +       mvebu_pcie_membase += MBUS_PCI_MEM_SIZE;
>
>         if (mvebu_mbus_add_window_by_id(pcie->mem_target, pcie->mem_attr,
>                                         (phys_addr_t)pcie->mem.start,
> -                                       PCIE_MEM_SIZE)) {
> +                                       MBUS_PCI_MEM_SIZE)) {
>                 printf("PCIe unable to add mbus window for mem at %08x+%08x\n",
> -                      (u32)pcie->mem.start, PCIE_MEM_SIZE);
> +                      (u32)pcie->mem.start, MBUS_PCI_MEM_SIZE);
>         }
>
>         pcie->io.start = (u32)mvebu_pcie_iobase;
> @@ -459,7 +466,7 @@ static int mvebu_pcie_probe(struct udevice *dev)
>
>         /* PCI memory space */
>         pci_set_region(hose->regions + 0, pcie->mem.start,
> -                      pcie->mem.start, PCIE_MEM_SIZE, PCI_REGION_MEM);
> +                      pcie->mem.start, MBUS_PCI_MEM_SIZE, PCI_REGION_MEM);
>         pci_set_region(hose->regions + 1,
>                        0, 0,
>                        gd->ram_size,
> @@ -659,6 +666,7 @@ static int mvebu_pcie_bind(struct udevice *parent)
>  static const struct udevice_id mvebu_pcie_ids[] = {
>         { .compatible = "marvell,armada-xp-pcie" },
>         { .compatible = "marvell,armada-370-pcie" },
> +       { .compatible = "marvell,kirkwood-pcie" },
>         { }
>  };
>

Cool! I will give it a try and let you know.

Thanks,
Tony