RE: [PATCH v2] Porting barebox to a new SoC

[Lior Weintraub <liorw@pliops.com>]

Hi Ahmad,

Thanks again for your great support and the patch.
I've checked it and it works perfectly!
The UART issue was solved after fixing the device tree per your recommendations.
Now I can write into barbox terminal :-)

When I type "cpuinfo" on the terminal I am getting:
implementer: ARM
architecture: v8
core: Cortex-A53 r0p4
exception level: 3
cache: no cache
Control register: P D Z DT IT U XP

Notice that it say "no cache".
I tried to add cache to cpu0 but it didn't help.

.
.
   d-cache-size = <0x8000>;
   d-cache-line-size = <64>;
   d-cache-sets = <128>; // 32KiB(size)/64(line-size)=512ways/4-way set
   i-cache-size = <0x8000>;
   i-cache-line-size = <64>;
   i-cache-sets = <256>; // 32KiB(size)/64(line-size)=512ways/2-way set
   next-level-cache = <&l2>;
};

l2: l2-cache0 {
   compatible = "cache";
   cache-unified;
   cache-size = <0x80000>;
   cache-line-size = <64>;
   cache-sets = <512>; // 512KiB(size)/64(line-size)=8192ways/16-way set
   cache-level = <2>;
}

 
Regarding Linux kernel:
This would be the next step but I assume that it would be a bit more complicated.
I guess we will have to integrate the interrupt controlled (GIC-600) into QEMU and into the device tree for it to work.
Is that a valid assumption?

Thanks,
Lior.




> -----Original Message-----
> From: Ahmad Fatoum <a.fatoum@pengutronix.de>
> Sent: Wednesday, May 31, 2023 8:55 PM
> To: Lior Weintraub <liorw@pliops.com>; Ahmad Fatoum <ahmad@a3f.at>;
> barebox@lists.infradead.org
> Subject: Re: [PATCH v2] Porting barebox to a new SoC
> 
> CAUTION: External Sender
> 
> Hi Lior,
> 
> On 31.05.23 18:13, Lior Weintraub wrote:
> > Hi Ahmad,
> >
> > Using end of SRAM as PBL stack is currently not working because we need
> 40bit address (0xC0_0020_0000).
> > This needs a fix to ENTRY_FUNCTION_WITHSTACK macro.
> 
> Ah, right. I just sent an (untested) patch. Would be cool if you could
> try it out.
> 
> > I tried just to change const u32 __stack_top = (stack_top); to const u64
> __stack_top = (stack_top); but there were linking errors caused by:
> > ASSERT(. - __pbl_board_stack_top <= 8, "Only One PBL per Image allowed")
> 
> The easy way would have been using a __attribute__((naked)) function, but
> those are only supported for arm32, not arm64. The alternative is thus
> writing the entry point in assembly and to make board authors life easier
> the linker script ensures that the stack setup entry point is invoked prior
> to the board entry.
> 
> > Regarding the arm timer:
> > Adding the timer entry to DT solved the issue.
> >
> > Regarding the UART:
> > Indeed CONFIG_SERIAL_AMBA_PL011 was set on spider_defconfig (also
> verified it generated the correct entry on .config).
> > I also noticed that if I remove the putc_ll implementation there is no Tx at all
> from Barebox.
> 
> I've led you astray. Indeed:
> 
> >>> of_platform_bus_create() - skipping /soc, no compatible prop
> 
> points at the issue.
> 
> Try adding into /soc
> 
>   compatible = "simple,bus";
>   ranges;
>   dma-ranges;
> 
> This matches /soc with the simple bus driver which just instantiates devices
> for the
> contained children. Those in turn should be matched by the drivers.
> 
> The ranges stuff just tells that memory and SoC peripherals exist in the same
> address space.
> 
> When it probes you may need to describe the clock in the DT. Eventually, you
> will
> want to have a clock driver for your hardware (good news: barebox and Linux
> have
> basically the same API, so you only need to write it once). But for now, you
> can
> fake it using fixed-clock in the DT. Take a look at:
> 
> snps,dw-apb-uart in arch/riscv/dts/jh7100.dtsi and compare with
> dts/src/arm/imx28.dtsi
> to see how to map that to PL011.
> 
> > Could it be a hint?
> 
> DEBUG_LL bridges the gap until a driver registers a console that's enabled. If
> this
> never happens, you are left with a non-interactive shell.
> 
> Cheers,
> Ahmad
> 
> >
> > Thanks,
> > Lior.
> >
> >> -----Original Message-----
> >> From: Ahmad Fatoum <a.fatoum@pengutronix.de>
> >> Sent: Wednesday, May 31, 2023 11:40 AM
> >> To: Lior Weintraub <liorw@pliops.com>; Ahmad Fatoum <ahmad@a3f.at>;
> >> barebox@lists.infradead.org
> >> Subject: Re: [PATCH v2] Porting barebox to a new SoC
> >>
> >> CAUTION: External Sender
> >>
> >> Hi Lior,
> >>
> >> On 31.05.23 10:05, Lior Weintraub wrote:
> >>> Hi Ahmad,
> >>>
> >>> Thanks again for your prompt reply and accurate tips!
> >>> Took the following changes:
> >>> 1. Increasing the DRAM size to 128MB (let barebox start from 0).
> >>> 2. Set PBL stack to offset 2MB from DRAM
> >>
> >> Just use end of SRAM, so you are completely independent of DRAM
> >> until you call barebox_arm_entry.
> >>
> >>> 3. Fix the device tree "memory" entry to have 128MB.
> >>
> >> (y)
> >>
> >>> 4. Load barebox-spider-mk1-evk.img to SRAM and run from there.
> >>>
> >>> Now I can see the following logs:
> >>> uncompress.c: memory at 0x00000000, size 0x08000000
> >>> uncompress.c: uncompressing barebox binary at 0x000000c0000021c0
> >> (size 0x0001e3a4) to 0x07e00000 (uncompressed size: 0x000390d0)
> >>> uncompress.c: jumping to uncompressed image at
> 0x0000000007e00000
> >>> start.c: memory at 0x00000000, size 0x08000000
> >>> start.c: found DTB in boarddata, copying to 0x07dffcc0
> >>> start.c: initializing malloc pool at 0x079ffcc0 (size 0x00400000)
> >>> start.c: starting barebox...
> >>> initcall-> command_slice_init+0x0/0x3c
> >>> initcall-> globalvar_init+0x0/0x80
> >>> register_device: global
> >>> register_device: nv
> >>> initcall-> platform_init+0x0/0x1c
> >>> register_device: platform
> >>> initcall-> amba_bus_init+0x0/0x1c
> >>> register_device: amba
> >>> initcall-> spi_bus_init+0x0/0x1c
> >>> register_device: spi
> >>> initcall-> gpio_desc_alloc+0x0/0x24
> >>> initcall-> fs_bus_init+0x0/0x1c
> >>> register_device: fs
> >>> initcall-> aarch64_init_vectors+0x0/0x50
> >>> initcall-> gpio_gate_clock_driver_register+0x0/0x1c
> >>> register_driver: gpio-gate-clock
> >>> initcall-> of_arm_init+0x0/0x5c
> >>> start.c: barebox_arm_boot_dtb: using barebox_boarddata
> >>> using boarddata provided DTB
> >>> adding DT alias:serial0: stem=serial id=0 node=/soc/serial@d000307000
> >>> register_device: machine
> >>> of_platform_bus_create() - skipping /chosen, no compatible prop
> >>> of_platform_bus_create() - skipping /aliases, no compatible prop
> >>> of_platform_bus_create() - skipping /cpus, no compatible prop
> >>> of_platform_bus_create() - skipping /memory@0, no compatible prop
> >>> of_platform_bus_create() - skipping /soc, no compatible prop
> >>> initcall-> register_autoboot_vars+0x0/0x70
> >>> initcall-> arm_arch_timer_driver_register+0x0/0x1c
> >>> register_driver: arm-architected-timer
> >>> initcall-> of_timer_init+0x0/0x20
> >>> initcall-> init_fs+0x0/0x3c
> >>> initcall-> pl011_driver_register+0x0/0x1c
> >>> register_driver: uart-pl011
> >>> initcall-> of_stdoutpath_init+0x0/0x28
> >>> initcall-> of_probe_memory+0x0/0x60
> >>> __request_region ok: 0x00000000:0x07ffffff flags=0x0
> >>> initcall-> __bare_init_end+0x0/0x6c
> >>> register_device: mem0
> >>> initcall-> of_reserved_mem_walk+0x0/0x1ac
> >>> initcall-> mem_malloc_resource+0x0/0xa8
> >>> __request_region ok: 0x079ffcc0:0x07dffcbf flags=0x200
> >>> __request_region ok: 0x07e00000:0x07e2aeff flags=0x200
> >>> __request_region ok: 0x07e2af00:0x07e390cf flags=0x200
> >>> __request_region ok: 0x07e390d0:0x07e3adaf flags=0x200
> >>> initcall-> bootsource_init+0x0/0x40
> >>> initcall-> ramfs_init+0x0/0x1c
> >>> register_driver: ramfs
> >>> initcall-> devfs_init+0x0/0x1c
> >>> register_driver: devfs
> >>> initcall-> arm_request_stack+0x0/0x398
> >>> __request_region ok: 0x07ff0000:0x07ff7fff flags=0x200
> >>> initcall-> mount_root+0x0/0x7c
> >>> mount: none on / type ramfs, options=
> >>> register_device: ramfs0
> >>>     probe-> ramfs0
> >>> mount: none on /dev type devfs, options=
> >>> register_device: devfs0
> >>>     probe-> devfs0
> >>> initcall-> binfmt_sh_init+0x0/0x1c
> >>> initcall-> binfmt_uimage_init+0x0/0x1c
> >>> initcall-> console_common_init+0x0/0x48
> >>> initcall-> of_kernel_init+0x0/0x28
> >>> initcall-> console_ctrlc_init+0x0/0x30
> >>> initcall-> mem_init+0x0/0x90
> >>> register_device: mem1
> >>> register_driver: mem
> >>>     probe-> mem0
> >>>     probe-> mem1
> >>> initcall-> of_partition_init+0x0/0x48
> >>> initcall-> prng_init+0x0/0x40
> >>> initcall-> null_init+0x0/0x40
> >>> initcall-> full_init+0x0/0x40
> >>> initcall-> zero_init+0x0/0x40
> >>> initcall-> spider_board_driver_register+0x0/0x1c
> >>> register_driver: board-spider
> >>>     probe-> machine
> >>> initcall-> barebox_memory_areas_init+0x0/0x40
> >>> __request_region ok: 0x07dffcc0:0x07dfffce flags=0x200
> >>> initcall-> barebox_of_populate+0x0/0x28
> >>> initcall-> of_register_memory_fixup+0x0/0x20
> >>> initcall-> dummy_csrc_warn+0x0/0x44
> >>> WARNING: Warning: Using dummy clocksource
> >>
> >> Add a arm,armv8-timer node into your SoC device tree.
> >> This lets barebox and Linux know that you have the ARM
> >> architected timer available. Without that, you'll notice
> >> that timeouts are wrong.
> >>
> >>> initcall-> bootm_init+0x0/0xf4
> >>> initcall-> init_command_list+0x0/0x40
> >>> register command bootm
> >>> register command cat
> >>> register command cd
> >>> register command clear
> >>> register command cp
> >>> register command cpuinfo
> >>> register command devinfo
> >>> register command drvinfo
> >>> register command echo
> >>> register command exit
> >>> register command false
> >>> register command help
> >>> register command ?
> >>> register command ll
> >>> register command ls
> >>> register command md
> >>> register command memcmp
> >>> register command memcpy
> >>> register command memset
> >>> register command mkdir
> >>> register command mount
> >>> register command mw
> >>> register command pwd
> >>> register command rm
> >>> register command rmdir
> >>> register command setenv
> >>> register command sh
> >>> register command source
> >>> register command .
> >>> register command test
> >>> register command [
> >>> register command true
> >>> register command :
> >>> register command umount
> >>> register command version
> >>> initcall-> display_meminfo+0x0/0xa8
> >>> barebox code: 0x7e00000 -> 0x7e2aeff
> >>> bss segment:  0x7e390d0 -> 0x7e3adaf
> >>> malloc space: 0x079ffcc0 -> 0x07dffcbf (size 4 MiB)
> >>> initcall-> of_register_bootargs_fixup+0x0/0x3c
> >>> initcall-> device_probe_deferred+0x0/0x14c
> >>> initcall-> of_init_hostname+0x0/0x28
> >>> initcall-> aarch64_register_image_handler+0x0/0x2c
> >>> initcall-> load_environment+0x0/0x4c
> >>> loading defaultenv
> >>> environment load /dev/env0: No such file or directory
> >>> Maybe you have to create the partition.
> >>> initcalls done
> >>>
> >>> Hit any to stop autoboot:    0
> >>> boot: No such file or directory
> >>> barebox:/
> >>>
> >>>
> >>> Few questions:
> >>> 1. The serial input doesn't work. i.e. I cannot type anything hence cannot
> >> interact with barebox terminal.
> >>
> >> DEBUG_LL only does otuput. For input, you will want to load the driver.
> >> Do you have CONFIG_SERIAL_AMBA_PL011 enabled?
> >>
> >>>      Does it require GIC and setting interrupts for it to work?
> >>
> >> No interrupts needed. barebox runs with interrupts disabled and
> everything
> >> is done cooperatively.
> >>
> >>> 2. What does "of_platform_bus_create() - skipping" means? Do I need to
> fix
> >> that?
> >>
> >> That's normal debugging output. Some device tree nodes are busses, which
> >> have
> >> children. These entries are skipped because they have no compatible. This is
> >> expected. I'd suggest you remove your VERBOSED_DEBUG define, so you
> are
> >> not
> >> spammed by too much debugging output.
> >>
> >>> 3. Looks like I am still missing some stuff (rootfs? Environment?
> Mounting?
> >> Partitions?)
> >>
> >> Take multi_v8_defconfig, open menuconfig and enable your SoC and use
> that.
> >> That will be quicker than enabling everything yourself. If it doesn't work
> >> out of the box, try imx_v8_defconfig.
> >>
> >> Once you get around to upstreaming your SoC, I'd suggest you just add it
> >> to multi_v8_defconfig. Not all ARMv8 SoCs are supported there, but those
> >> that are make development easier, because we don't need to build as many
> >> different configs..
> >>
> >> Cheers,
> >> Ahmad
> >>
> >>>
> >>> Thanks,
> >>> Have a great day,
> >>> Lior.
> >>>
> >>>
> >>>> -----Original Message-----
> >>>> From: Ahmad Fatoum <a.fatoum@pengutronix.de>
> >>>> Sent: Wednesday, May 31, 2023 9:11 AM
> >>>> To: Lior Weintraub <liorw@pliops.com>; Ahmad Fatoum
> <ahmad@a3f.at>;
> >>>> barebox@lists.infradead.org
> >>>> Subject: Re: [PATCH v2] Porting barebox to a new SoC
> >>>>
> >>>> CAUTION: External Sender
> >>>>
> >>>> Hi Lior,
> >>>>
> >>>> On 30.05.23 22:10, Lior Weintraub wrote:
> >>>>> Hello Ahmad,
> >>>>>
> >>>>> Thanks again for your kind support!
> >>>>> Your comments helped me progress and the current situation is as
> >> follows:
> >>>>> Our QEMU Spider machine is running a BL1.elf file using the following
> >>>> command:
> >>>>> QEMU_AUDIO_DRV=none qemu-system-aarch64 -M spider-soc -smp 1
> -
> >> m
> >>>> 128M -nographic \
> >>>>>       -device loader,file=BL1.elf -cpu cortex-a53,rvbar=0xC004000000 \
> >>>>>       -d unimp -semihosting-config enable=on,target=native \
> >>>>>       -monitor telnet:localhost:1235,server,nowait \
> >>>>>       -gdb tcp::1236
> >>>>>
> >>>>> The BL1.elf is our BootROM application that runs from ROM address
> >>>> 0xC004000000.
> >>>>> Just for debugging purpose we've increased the ROM size so it can
> include
> >>>> the images/barebox-spider-mk1-evk.img (as a const array).
> >>>>> BL1 then copy it (using memcpy) to address 0 and jumps there for
> >>>> execution.
> >>>>
> >>>> Sounds ok.
> >>>>
> >>>>> On the real ASIC this address will be the DRAM and indeed will need to
> be
> >>>> initialized before the copy but here on QEMU it is not required.
> >>>>
> >>>> I see. You could still have your bootrom move barebox into SRAM and
> then
> >>>>
> >>>>   barebox_arm_entry(DRAM_ADDR, SZ_128M,
> >> __dtb_spider_mk1_evk_start);
> >>>>
> >>>> To have PBL extract barebox to DRAM. Even if you don't need need
> DRAM
> >>>> setup in QEMU, the flow would be similar to what you will have on actual
> >>>> silicon.
> >>>>
> >>>>> The lowlevel.c of spider-evk was modified to use DRAM_ADDR
> 0x400000
> >>>> (4MB from start) and MY_STACK_TOP was set to 0x8000000 (128M).
> >>>>
> >>>> That's not needed. While you don't have control where barebox PBL will
> be
> >>>> located
> >>>> (depends on BootROM), barebox will extract itself to the end of DRAM
> >>>> without
> >>>> overwriting itself, so you can just use DRAM_ADDR 0 normally.
> Eventually,
> >>>> stack
> >>>> top should go into SRAM, but anywhere that works is ok.
> >>>>
> >>>>> In addition, I implemented putc_ll (currently hard-coded in
> >>>> include/debug_ll.h) and opened log level to VERBOSE_DEBUG (currently
> >> just
> >>>> hard-coded in printk.h).
> >>>>
> >>>> There's CONFIG_DEBUG_PBL you can enable to get all these messages by
> >>>> default.
> >>>>
> >>>>> I see the following (which makes sense) logs on QEMU terminal:
> >>>>> uncompress.c: memory at 0x00400000, size 0x00200000
> >>>>> uncompress.c: uncompressing barebox binary at
> 0x0000000000002200
> >>>> (size 0x0001d3b2) to 0x00400000 (uncompressed size: 0x000373d0)
> >>>>
> >>>> Why pass only 2M to barebox_arm_entry? While this need not be the
> >> whole
> >>>> of RAM, this
> >>>> initial memory is what barebox will use for itself including its final stack
> and
> >>>> malloc area. barebox will also not place itself into the last 1M AFAIK, so
> 2M
> >>>> may not work ok. You should use the minimum possible RAM here or if
> you
> >>>> can detect
> >>>> in PBL how much RAM you have or just the whole RAM bank. I am not
> sure
> >>>> anything lower
> >>>> than SZ_4M would work ok. (Note this is DRAM size, not SRAM. barebox
> >> PBL
> >>>> is fine being
> >>>> called from 64K SRAMs, it just needs DRAM to extract to).
> >>>>
> >>>>> I then connect with aarch64-none-elf-gdb, load the barebox symbols
> (to
> >>>> 0x400000) and check the current execution state (program counter and
> >>>> stack).
> >>>>> Looks like the code is stuck on function register_autoboot_vars:
> >>>>> sp             0x5f7e60            0x5f7e60
> >>>>> pc             0x401264            0x401264 <register_autoboot_vars+24>
> >>>>>
> >>>>> Few observations:
> >>>>> 1. The PBL was using stack top located on 0x8000000 (which is
> >>>> MY_STACK_TOP). Found it be causing a breakpoint on the PBL.
> >>>>> 2. Barebox uses a stack top on 0x600000 which is probably calculated
> >> from
> >>>> my new DRAM_ADDR and SZ_2M given to the function call:
> >>>>>     barebox_arm_entry(DRAM_ADDR, SZ_2M,
> >> __dtb_spider_mk1_evk_start);
> >>>>>
> >>>>> This is great! I am starting to find my way.
> >>>>
> >>>> :) Ye, the ENTRY_FUNCTION_WITHSTACK is only when the BootROM
> >> doesn't
> >>>> enter
> >>>> with a valid stack pointer. It's overwritten as soon as barebox is told
> >>>> about the initial memory layout (with barebox_arm_entry).
> >>>>
> >>>>> When the barebox execution didn't print anything to the terminal I
> >>>> remembered that we used a place holder on the dtsi for the uart.
> >>>>> So now I changed it to:
> >>>>> uart0: serial@d000307000 {
> >>>>>        compatible = "arm,pl011", "arm,primecell";
> >>>>>        reg = <0xd0 0x307000 0 0x1000>;
> >>>>> }
> >>>>> (Our QEMU UART is currently using pl011 device.)
> >>>>
> >>>> Looks ok. Don't forget to enable the driver (via make menuconfig).
> >>>>
> >>>>> After some time (trying to debug by enabling MMU but then reverted
> the
> >>>> code back), I got to a point that when I try to run again I am getting an
> >>>> exception.
> >>>>> I can swear all code changes were reverted back to the point where I
> saw
> >> the
> >>>> barebox stuck on register_autoboot_vars but now it just cases an
> >> exception.
> >>>>> The exception vector code is located on our ROM (part of BL1 code) and
> >> the
> >>>> logs shows that the link register has the value 0x401218 which suggest
> the
> >>>> following code:
> >>>>> 0000000000001200 <load_environment>:
> >>>>> 1200: a9be7bfd        stp     x29, x30, [sp, #-32]!
> >>>>> 1204: 910003fd        mov     x29, sp
> >>>>> 1208: a90153f3        stp     x19, x20, [sp, #16]
> >>>>> 120c: 94000a07        bl      3a28 <default_environment_path_get>
> >>>>> 1210: d00000f3        adrp    x19, 1f000 <do_cpuinfo+0x1f0>
> >>>>> 1214: 912a7273        add     x19, x19, #0xa9c
> >>>>> 1218: aa0003f4        mov     x20, x0
> >>>>>
> >>>>> Any ideas or suggestions how to proceed with the debugging?
> >>>>
> >>>> You shouldn't need to touch the MMU code. If your initial memory setup
> >>>> is wonky, you may end up overwriting stuff. Try again with bigger
> memory.
> >>>>
> >>>>> BTW, to answer your questions:
> >>>>> The SRAM of 4MB is the only one we have because we assumed it is
> only
> >> for
> >>>> BootROM to load a PBL
> >>>>
> >>>> Ok. Sometimes there are SRAMs for use with DMA. I asked, because a
> >> SRAM
> >>>> in the first 4M
> >>>> would lend itself nicely as stack, but if there is none, we can adjust
> >>>> ENTRY_FUNCTION_WITHSTACK to accept a 64-bit parameter.
> >>>>
> >>>> Cheers,
> >>>> Ahmad
> >>>>
> >>>>> Thank you very much,
> >>>>> Cheers,
> >>>>> Lior.
> >>>>>
> >>>>>
> >>>>>> -----Original Message-----
> >>>>>> From: Ahmad Fatoum <a.fatoum@pengutronix.de>
> >>>>>> Sent: Monday, May 29, 2023 10:03 PM
> >>>>>> To: Lior Weintraub <liorw@pliops.com>; Ahmad Fatoum
> >> <ahmad@a3f.at>;
> >>>>>> barebox@lists.infradead.org
> >>>>>> Subject: Re: [PATCH v2] Porting barebox to a new SoC
> >>>>>>
> >>>>>> CAUTION: External Sender
> >>>>>>
> >>>>>> Hello Lior,
> >>>>>>
> >>>>>> On 29.05.23 15:34, Lior Weintraub wrote:
> >>>>>>> Hi Ahmad,
> >>>>>>>
> >>>>>>> I have revised the addresses and used DRAM address @ 0 instead:
> >>>>>>> #define UARTBASE        (0xD000307000)
> >>>>>>> #define DRAM_ADDR       (0x00000000)
> >>>>>>> #define MY_STACK_TOP    (0x00000000 + SZ_2M) // Set the stack
> 2MB
> >>>> from
> >>>>>> DRAM start
> >>>>>>
> >>>>>> Is DRAM configured by the time barebox runs? If not, you should keep
> >>>> stack
> >>>>>> top
> >>>>>> in SRAM, until you have setup memory in prebootloader (PBL). Is the
> 4M
> >>>>>> SRAM
> >>>>>> the only on-chip SRAM you have?
> >>>>>>
> >>>>>>> static inline void spider_serial_putc(void *base, int c)
> >>>>>>> {
> >>>>>>>     *((volatile unsigned *)base) = c;
> >>>>>>
> >>>>>> There's a helper for that: writel(c, base); In barebox, it's equivalent
> >>>>>> to the volatile access, but in Linux it involves a write memory barrier.
> >>>>>> We try to write code in barebox, so it's easily reusable in Linux (and
> >>>>>> the other way round).
> >>>>>>
> >>>>>>> }
> >>>>>>>
> >>>>>>> I will try to test it on QEMU using an initial QEMU machine we made
> for
> >>>>>> Spider.
> >>>>>>> In this machine we only have 3 memory regions and a PL011 UART:
> >>>>>>> spider_soc_memories soc_memories[] = {
> >>>>>>>     {.name = "SPIDER_GPRAM",   .add = 0xC000000000ULL, .size = 4 *
> >> MiB},
> >>>>>>>     {.name = "SPIDER_ROM",     .add = 0xC004000000ULL, .size = 128 *
> >>>> KiB},
> >>>>>>>     {.name = "SPIDER_DRAM",    .add = 0x0000000000ULL, .size = 1 *
> >> GiB},
> >>>>>>> };
> >>>>>>>
> >>>>>>> This special QEMU machine can run our BL1 code from "ROM"
> address
> >>>> (we
> >>>>>> set the RVBAR to point there).
> >>>>>>> So my idea is to test the barebox image by the following steps:
> >>>>>>> 1. Modify the QEMU code to have a "ROM" with the size of 128M.
> >>>>>>> 2. Compile our BL1 code to include the barebox.bin as a const array,
> >> copy
> >>>> it
> >>>>>> to "DRAM" @ address 0 and jump there.
> >>>>>>
> >>>>>> Why not map QEMU -bios option to SRAM? (Or DRAM directly, if it
> >> needs
> >>>> no
> >>>>>> special setup from
> >>>>>> barebox side).
> >>>>>>
> >>>>>>> For this to work I wanted to understand how to call (i.e. what
> >> arguments
> >>>> to
> >>>>>> pass) to barebox.
> >>>>>>
> >>>>>> barebox doesn't expect any arguments, because most BootROMs
> don't
> >>>> pass
> >>>>>> anything useful.
> >>>>>> Some pass information about bootsource though, so that's why the
> >>>>>> ENTRY_FUNCTION has
> >>>>>> r0, r1 and r2 as parameters, but you need not use them.
> >>>>>>
> >>>>>>> So I checked the barebox.map and found the function "start" on
> >> address
> >>>> 0.
> >>>>>>
> >>>>>> You may know that Linux on some platforms comes with a
> decompressor
> >>>> that
> >>>>>> is glued to the
> >>>>>> front of the kernel image and extracts the compressed kernel image.
> >>>> barebox
> >>>>>> has the same
> >>>>>> concept. The prebootloader is uncompressed and runs (starting from
> >>>>>> ENTRY_FUNCTION) and
> >>>>>> then does some early setup (e.g. enable clocks, configure PMIC, setup
> >>>> DRAM,
> >>>>>> load secure
> >>>>>> monitor (BL31), ...etc.) and then it decompresses barebox proper into
> >>>> DRAM.
> >>>>>>
> >>>>>> barebox.bin <- barebox proper. You don't usually need that.
> >>>>>> barebox.elf <- ELF binary for the above (for gdb)
> >>>>>> barebox.map <- map file of the above
> >>>>>>
> >>>>>> images/barebox-spider-mk1-evk.img   <- complete barebox image (PBL
> +
> >>>>>> barebox proper)
> >>>>>> images/start_spider_mk1_evk.pbl     <- ELF image for the above
> >>>>>> images/start_spider_mk1_evk.pbl.map <- map file of the above
> >>>>>>
> >>>>>> If you want to follow barbeox from the start, begin at
> >>>> start_spider_mk1_evk.
> >>>>>>
> >>>>>>> Then I went to arch/arm/cpu/start.c and realized that the code is
> >> compiled
> >>>>>> with CONFIG_PBL_IMAGE.
> >>>>>>> In that case I assume I need to pass 3 arguments and use this
> function
> >>>>>> prototype:
> >>>>>>> void start(unsigned long membase, unsigned long memsize, void
> >>>>>> *boarddata);
> >>>>>>
> >>>>>> barebox prebootloader takes care of this, so you don't need to do
> >> anything.
> >>>>>>
> >>>>>>> Few questions:
> >>>>>>> 1. Will that call work:
> >>>>>>>     typedef void (*barebox_start)(unsigned long , unsigned long , void
> *);
> >>>>>>>     #define DRAM_START  (0)
> >>>>>>>     barebox_start p_barebox = (barebox_start)DRAM_START;
> >>>>>>>     p_barebox(DRAM_START, DRAM_START+SZ_2M, (void
> >>>>>> *)(DRAM_START+SZ_4M));
> >>>>>>>     This assumes that my BL1 code also copied the device tree
> (barebox-
> >> dt-
> >>>>>> 2nd.img? start_dt_2nd.pblb? start_spider_mk1_evk.pblb?)
> >>>>>>
> >>>>>> The device tree is built into the PBL and passed to barebox proper. This
> >>>>>> allows us to use the same barebox proper binary and link it with a
> >> different
> >>>>>> prebootloader for each SoC/board, all in the same build.
> >>>>>>
> >>>>>> barebox-dt-2nd.img is a special image that looks exactly like a Linux
> >> kernel:
> >>>>>>
> >>>>>>   images/barebox-dt-2nd.img: Linux kernel ARM64 boot executable
> >> Image,
> >>>>>> little-endian, 4K pages
> >>>>>>
> >>>>>> and can thus be used for booting for easy chainloading from other
> >>>>>> bootloaders or for running
> >>>>>> with QEMU -kernel. You shouldn't need it right now.
> >>>>>>
> >>>>>>> 2. Do I want to have my code compiled with CONFIG_PBL_IMAGE?
> >>>>>>>     If I understand correctly, it means that my code will provide a PBL
> >> (a.k.a
> >>>>>> BL2) which will set the DRAM and STACK among other things (MMU?).
> >>>>>>
> >>>>>> The patch I sent already builds a PBL. You will need to fill out
> >>>>>> start_spider_mk1_evk
> >>>>>> to do all the other early initialization you need. Then you call
> >>>>>> barebox_arm_entry
> >>>>>> with device tree and memory size and it will take care to do stack setup
> in
> >>>> new
> >>>>>> memory region, MMU setup (if enabled) and chainloading barebox
> >> proper.
> >>>>>>
> >>>>>> Note that PBL isn't necessary BL2. You can chainload barebox from
> within
> >>>>>> barebox (i.e.
> >>>>>> in EL2 or EL1), which is useful for debugging. You will thus often find
> PBL
> >>>> code
> >>>>>> that
> >>>>>> does
> >>>>>>
> >>>>>>   if (current_el() == 3) {
> >>>>>>         /* Do BL2 setup */
> >>>>>>         chainload();
> >>>>>>         __builtin_unreachable();
> >>>>>>   }
> >>>>>>
> >>>>>>   barebox_arm_entry(...)
> >>>>>>
> >>>>>> See for example arch/arm/boards/innocomm-imx8mm-
> wb15/lowlevel.c
> >>>>>>
> >>>>>> to see a real-world example of another Cortex-A53.
> >>>>>>
> >>>>>>>     In that case I assume it is OK.
> >>>>>>> 3. If I try to remove it by having CONFIG_PBL_IMAGE=n on
> >>>> spider_defconfig
> >>>>>> this doesn't do anything
> >>>>>>>     The build (make spider_defconfig) ignores it and say that " No
> change
> >> to
> >>>>>> .config ".
> >>>>>>
> >>>>>> Another symbol forces it to be enabled. If you are curious, run make
> >>>>>> menuconfig
> >>>>>> and then search (/) for the symbol and it will list, whether it's enabled
> >> and
> >>>>>> why:
> >>>>>>
> >>>>>>   Selected by [y]:
> >>>>>>     - PBL_MULTI_IMAGES [=y] && HAVE_PBL_MULTI_IMAGES [=y]
> >>>>>>
> >>>>>> I'd suggest you avoid modifying the .config file manually. always use
> >>>>>> menuconfig.
> >>>>>>
> >>>>>>> 4. I also tried to understand how to implement PUTC_LL but not sure
> I
> >>>>>> understand.
> >>>>>>>    4.1 When I set "CONFIG_DEBUG_LL=y" on spider_defconfig it is
> again
> >>>> not
> >>>>>> written to .config and I get " No change to .config " message.
> >>>>>>
> >>>>>> You must:
> >>>>>>
> >>>>>>   - select HAS_DEBUG_LL from MACH_SPIDER
> >>>>>>   - Add your arch to arch/arm/include/asm/debug_ll.h
> >>>>>>   - Then implement PUTC_LL in e.g. mach/spider/debug_ll.h
> >>>>>>
> >>>>>>>    4.2 Do I need to have my own debug_ll.h file?
> >>>>>>
> >>>>>> Yes. See above.
> >>>>>>
> >>>>>>> 5. When I make changes to spider_defconfig and try to regenerate
> the
> >>>>>> .config and I get " No change to .config " message, does it mean that
> >> those
> >>>>>> macros are "hidden" symbols like you said about the
> CONFIG_CPU_V8?
> >>>>>>
> >>>>>> Yes. Just check menuconfig to see how symbols relate to each other.
> >>>>>> This is 1:1 like it's in Linux, so it'll come in handy when you do
> >>>>>> the kernel port too ;)
> >>>>>>
> >>>>>>> Apologize for so many questions :-)
> >>>>>>
> >>>>>> No problem. Looking forward to your patches ;)
> >>>>>>
> >>>>>>
> >>>>>> Cheers,
> >>>>>> Ahmad
> >>>>>>
> >>>>>>> Cheers,
> >>>>>>> Lior.
> >>>>>>>
> >>>>>>> -----Original Message-----
> >>>>>>> From: Lior Weintraub
> >>>>>>> Sent: Sunday, May 28, 2023 11:16 PM
> >>>>>>> To: Ahmad Fatoum <ahmad@a3f.at>; barebox@lists.infradead.org
> >>>>>>> Subject: RE: [PATCH v2] Porting barebox to a new SoC
> >>>>>>>
> >>>>>>> Hi Ahmad,
> >>>>>>>
> >>>>>>> Thank you so much for your kind support!
> >>>>>>>
> >>>>>>> Indeed we also have a 16GB DRAM that starts from address 0
> (though
> >>>>>> currently we don't have the controller settings (under development)).
> >>>>>>>
> >>>>>>> I also wrote the BootROM (BL1) for this SoC (128KB ROM @ address
> >>>>>> 0xC004000000).
> >>>>>>> I understand now that it would be best for me to develop BL2 that
> will
> >> run
> >>>>>> from our SRAM.
> >>>>>>>
> >>>>>>> As this BL2 code is bare-metal I have no problem or limitations with
> the
> >> 40
> >>>>>> bit addresses.
> >>>>>>> The BL2 code will initialize the DRAM controller and then copy
> Barebox
> >>>> image
> >>>>>> from NOR Flash to address 0 of the DRAM.
> >>>>>>> Our NOR Flash is 128MB in size and it is accessed via QSPI controller.
> >>>>>>>
> >>>>>>> I tried applying your suggested patch but got an error while doing so:
> >>>>>>> $git apply 0002-Ahmad.patch
> >>>>>>> 0002-Ahmad.patch:115: trailing whitespace.
> >>>>>>>       .of_compatible = spider_board_of_match, };
> >>>>>>> error: corrupt patch at line 117
> >>>>>>>
> >>>>>>> After some digging I found that my Outlook probably messed with
> the
> >>>> patch
> >>>>>> format (even though I am using text only and no HTML format).
> >>>>>>> When I went to the web and copied the patch from there (mailing list
> >>>>>> archive) it was working well (i.e. no compilation error).
> >>>>>>>
> >>>>>>> Cheers,
> >>>>>>> Lior.
> >>>>>>>
> >>>>>>> -----Original Message-----
> >>>>>>> From: Ahmad Fatoum <ahmad@a3f.at>
> >>>>>>> Sent: Sunday, May 28, 2023 6:38 PM
> >>>>>>> To: barebox@lists.infradead.org
> >>>>>>> Cc: Lior Weintraub <liorw@pliops.com>
> >>>>>>> Subject: [PATCH v2] Porting barebox to a new SoC
> >>>>>>>
> >>>>>>> CAUTION: External Sender
> >>>>>>>
> >>>>>>> From: Lior Weintraub <liorw@pliops.com>
> >>>>>>>
> >>>>>>> Hi,
> >>>>>>>
> >>>>>>> I tried to follow the porting guide on https://ddec1-0-en-
> >>>>>>
> >>>>
> >>
> ctp.trendmicro.com:443/wis/clicktime/v1/query?url=https%3a%2f%2fwww.
> >>>>>>
> >>>>
> >>
> barebox.org%2fdoc%2flatest%2fdevel%2fporting.html%23&umid=60097eda
> >>>>>> -f136-45a1-9c8e-
> >>>>>>
> cf6a76e45cf8&auth=860a7ebb9feba264acc79b6e38eb59582349362c-
> >>>>>> 480ae23736add41c88ab8d30c090a75517ca7f9e but couldn't follow
> >> the
> >>>>>> instructions.
> >>>>>>> I would like to port barebox to a new SoC (which is not a derivative of
> >> any
> >>>>>> known SoC).
> >>>>>>> It has the following:
> >>>>>>> * Single Cortex A53
> >>>>>>> * SRAM (4MB) located on address 0xC000000000
> >>>>>>>
> >>>>>>> The below patch shows my initial test to try and have a starting point.
> >>>>>>> I am setting env variables:
> >>>>>>> export ARCH=arm64
> >>>>>>> export CROSS_COMPILE=/home/pliops/workspace/ARM/arm-gnu-
> >>>>>> toolchain/bin/aarch64-none-elf-
> >>>>>>>
> >>>>>>> Then I build with:
> >>>>>>> make spider_defconfig && make
> >>>>>>>
> >>>>>>> This gives an error:
> >>>>>>> aarch64-none-elf-gcc: error: unrecognized argument in option '-
> >>>> mabi=apcs-
> >>>>>> gnu'
> >>>>>>> aarch64-none-elf-gcc: note: valid arguments to '-mabi=' are: ilp32
> lp64
> >>>>>>> aarch64-none-elf-gcc: error: unrecognized command-line option '-
> >> msoft-
> >>>>>> float'
> >>>>>>> aarch64-none-elf-gcc: error: unrecognized command-line option '-
> mno-
> >>>>>> unaligned-access'
> >>>>>>> /home/pliops/workspace/simplest-linux-
> >>>>>> demo/barebox/scripts/Makefile.build:140: recipe for target
> >>>>>> 'scripts/mod/empty.o' failed
> >>>>>>> make[2]: *** [scripts/mod/empty.o] Error 1
> >>>>>>>
> >>>>>>> Not sure why the compiler flags get -mabi=apcs-gnu when I explicitly
> set
> >>>>>> CONFIG_CPU_V8 and the arch/arm/Makefile has:
> >>>>>>> ifeq ($(CONFIG_CPU_V8), y)
> >>>>>>> CFLAGS_ABI      :=-mabi=lp64
> >>>>>>>
> >>>>>>> The changes I did:
> >>>>>>> >From 848b5f9b18bb1bb96d197cbc1b368ee0a729d581 Mon Sep
> 17
> >>>>>> 00:00:00 2001
> >>>>>>> ---
> >>>>>>>  arch/arm/Kconfig                      | 13 ++++++++
> >>>>>>>  arch/arm/Makefile                     |  1 +
> >>>>>>>  arch/arm/boards/Makefile              |  1 +
> >>>>>>>  arch/arm/boards/spider-evk/Makefile   |  4 +++
> >>>>>>>  arch/arm/boards/spider-evk/board.c    | 26 +++++++++++++++
> >>>>>>>  arch/arm/boards/spider-evk/lowlevel.c | 30 +++++++++++++++++
> >>>>>>>  arch/arm/configs/spider_defconfig     |  8 +++++
> >>>>>>>  arch/arm/dts/Makefile                 |  1 +
> >>>>>>>  arch/arm/dts/spider-mk1-evk.dts       | 10 ++++++
> >>>>>>>  arch/arm/dts/spider-mk1.dtsi          | 46
> >> +++++++++++++++++++++++++++
> >>>>>>>  arch/arm/mach-spider/Kconfig          | 16 ++++++++++
> >>>>>>>  arch/arm/mach-spider/Makefile         |  1 +
> >>>>>>>  arch/arm/mach-spider/lowlevel.c       | 14 ++++++++
> >>>>>>>  images/Makefile                       |  1 +
> >>>>>>>  images/Makefile.spider                |  5 +++
> >>>>>>>  include/mach/spider/lowlevel.h        |  7 ++++
> >>>>>>>  16 files changed, 184 insertions(+)
> >>>>>>>  create mode 100644 arch/arm/boards/spider-evk/Makefile
> >>>>>>>  create mode 100644 arch/arm/boards/spider-evk/board.c
> >>>>>>>  create mode 100644 arch/arm/boards/spider-evk/lowlevel.c
> >>>>>>>  create mode 100644 arch/arm/configs/spider_defconfig  create
> mode
> >>>>>> 100644 arch/arm/dts/spider-mk1-evk.dts  create mode 100644
> >>>>>> arch/arm/dts/spider-mk1.dtsi  create mode 100644 arch/arm/mach-
> >>>>>> spider/Kconfig  create mode 100644 arch/arm/mach-spider/Makefile
> >>>> create
> >>>>>> mode 100644 arch/arm/mach-spider/lowlevel.c  create mode 100644
> >>>>>> images/Makefile.spider  create mode 100644
> >>>> include/mach/spider/lowlevel.h
> >>>>>>>
> >>>>>>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index
> >>>>>> e76ee0f6dfe1..e5dcf128447e 100644
> >>>>>>> --- a/arch/arm/Kconfig
> >>>>>>> +++ b/arch/arm/Kconfig
> >>>>>>> @@ -255,6 +255,18 @@ config ARCH_ROCKCHIP
> >>>>>>>         select HAS_DEBUG_LL
> >>>>>>>         imply GPIO_ROCKCHIP
> >>>>>>>
> >>>>>>> +config ARCH_SPIDER
> >>>>>>> +       bool "Pliops Spider based"
> >>>>>>> +       depends on 64BIT
> >>>>>>> +       depends on ARCH_MULTIARCH
> >>>>>>> +       select GPIOLIB
> >>>>>>> +       select HAVE_PBL_MULTI_IMAGES
> >>>>>>> +       select COMMON_CLK
> >>>>>>> +       select CLKDEV_LOOKUP
> >>>>>>> +       select COMMON_CLK_OF_PROVIDER
> >>>>>>> +       select OFTREE
> >>>>>>> +       select OFDEVICE
> >>>>>>> +
> >>>>>>>  config ARCH_STM32MP
> >>>>>>>         bool "STMicroelectronics STM32MP"
> >>>>>>>         depends on 32BIT
> >>>>>>> @@ -331,6 +343,7 @@ source "arch/arm/mach-omap/Kconfig"
> >>>>>>>  source "arch/arm/mach-pxa/Kconfig"
> >>>>>>>  source "arch/arm/mach-rockchip/Kconfig"
> >>>>>>>  source "arch/arm/mach-socfpga/Kconfig"
> >>>>>>> +source "arch/arm/mach-spider/Kconfig"
> >>>>>>>  source "arch/arm/mach-stm32mp/Kconfig"
> >>>>>>>  source "arch/arm/mach-versatile/Kconfig"
> >>>>>>>  source "arch/arm/mach-vexpress/Kconfig"
> >>>>>>> diff --git a/arch/arm/Makefile b/arch/arm/Makefile index
> >>>>>> 35ebc70f44e2..4c63dfee48f4 100644
> >>>>>>> --- a/arch/arm/Makefile
> >>>>>>> +++ b/arch/arm/Makefile
> >>>>>>> @@ -101,6 +101,7 @@ machine-$(CONFIG_ARCH_MXS)          += mxs
> >>>>>>>  machine-$(CONFIG_ARCH_MVEBU)           += mvebu
> >>>>>>>  machine-$(CONFIG_ARCH_NOMADIK)         += nomadik
> >>>>>>>  machine-$(CONFIG_ARCH_OMAP)            += omap
> >>>>>>> +machine-$(CONFIG_ARCH_SPIDER)          += spider
> >>>>>>>  machine-$(CONFIG_ARCH_PXA)             += pxa
> >>>>>>>  machine-$(CONFIG_ARCH_ROCKCHIP)                += rockchip
> >>>>>>>  machine-$(CONFIG_ARCH_SAMSUNG)         += samsung
> >>>>>>> diff --git a/arch/arm/boards/Makefile b/arch/arm/boards/Makefile
> >> index
> >>>>>> 2877debad535..6fe0a90c81ea 100644
> >>>>>>> --- a/arch/arm/boards/Makefile
> >>>>>>> +++ b/arch/arm/boards/Makefile
> >>>>>>> @@ -135,6 +135,7 @@ obj-
> >>>>>> $(CONFIG_MACH_SOCFPGA_TERASIC_DE10_NANO)        += terasic-
> >> de10-
> >>>>>> nano/
> >>>>>>>  obj-$(CONFIG_MACH_SOCFPGA_TERASIC_SOCKIT)      += terasic-
> >> sockit/
> >>>>>>>  obj-$(CONFIG_MACH_SOLIDRUN_CUBOX)              += solidrun-cubox/
> >>>>>>>  obj-$(CONFIG_MACH_SOLIDRUN_MICROSOM)           += solidrun-
> >>>>>> microsom/
> >>>>>>> +obj-$(CONFIG_MACH_SPIDER_MK1_EVK)              += spider-evk/
> >>>>>>>  obj-$(CONFIG_MACH_STM32MP15XX_DKX)             +=
> stm32mp15xx-
> >>>> dkx/
> >>>>>>>  obj-$(CONFIG_MACH_STM32MP13XX_DK)              += stm32mp13xx-
> >> dk/
> >>>>>>>  obj-$(CONFIG_MACH_LXA_MC1)                     += lxa-mc1/
> >>>>>>> diff --git a/arch/arm/boards/spider-evk/Makefile
> >>>>>> b/arch/arm/boards/spider-evk/Makefile
> >>>>>>> new file mode 100644
> >>>>>>> index 000000000000..da63d2625f7a
> >>>>>>> --- /dev/null
> >>>>>>> +++ b/arch/arm/boards/spider-evk/Makefile
> >>>>>>> @@ -0,0 +1,4 @@
> >>>>>>> +# SPDX-License-Identifier: GPL-2.0-only
> >>>>>>> +
> >>>>>>> +obj-y += board.o
> >>>>>>> +lwl-y += lowlevel.o
> >>>>>>> diff --git a/arch/arm/boards/spider-evk/board.c
> >>>> b/arch/arm/boards/spider-
> >>>>>> evk/board.c
> >>>>>>> new file mode 100644
> >>>>>>> index 000000000000..3920e83b457d
> >>>>>>> --- /dev/null
> >>>>>>> +++ b/arch/arm/boards/spider-evk/board.c
> >>>>>>> @@ -0,0 +1,26 @@
> >>>>>>> +#include <bbu.h>
> >>>>>>> +#include <boot.h>
> >>>>>>> +#include <bootm.h>
> >>>>>>> +#include <common.h>
> >>>>>>> +#include <deep-probe.h>
> >>>>>>> +#include <environment.h>
> >>>>>>> +#include <fcntl.h>
> >>>>>>> +#include <globalvar.h>
> >>>>>>> +
> >>>>>>> +static int spider_board_probe(struct device *dev) {
> >>>>>>> +      /* Do some board-specific setup */
> >>>>>>> +      return 0;
> >>>>>>> +}
> >>>>>>> +
> >>>>>>> +static const struct of_device_id spider_board_of_match[] = {
> >>>>>>> +      { .compatible = "pliops,spider-mk1-evk" },
> >>>>>>> +      { /* sentinel */ },
> >>>>>>> +};
> >>>>>>> +
> >>>>>>> +static struct driver spider_board_driver = {
> >>>>>>> +      .name = "board-spider",
> >>>>>>> +      .probe = spider_board_probe,
> >>>>>>> +      .of_compatible = spider_board_of_match, };
> >>>>>>> +device_platform_driver(spider_board_driver);
> >>>>>>> diff --git a/arch/arm/boards/spider-evk/lowlevel.c
> >>>>>> b/arch/arm/boards/spider-evk/lowlevel.c
> >>>>>>> new file mode 100644
> >>>>>>> index 000000000000..e36fcde4208e
> >>>>>>> --- /dev/null
> >>>>>>> +++ b/arch/arm/boards/spider-evk/lowlevel.c
> >>>>>>> @@ -0,0 +1,30 @@
> >>>>>>> +#include <common.h>
> >>>>>>> +#include <asm/barebox-arm.h>
> >>>>>>> +#include <mach/spider/lowlevel.h>
> >>>>>>> +
> >>>>>>> +#define BASE_ADDR       (0xD000307000)
> >>>>>>> +#define GPRAM_ADDR      (0xC000000000)
> >>>>>>> +#define MY_STACK_TOP    (0xC000000000 + SZ_2M) // Set the stack
> >>>> 2MB
> >>>>>> from GPRAM start (excatly in the middle)
> >>>>>>> +static inline void spider_serial_putc(void *base, int c) {
> >>>>>>> +//     if (!(readl(base + UCR1) & UCR1_UARTEN))
> >>>>>>> +//             return;
> >>>>>>> +//
> >>>>>>> +//     while (!(readl(base + USR2) & USR2_TXDC));
> >>>>>>> +//
> >>>>>>> +//     writel(c, base + URTX0);
> >>>>>>> +}
> >>>>>>> +
> >>>>>>> +ENTRY_FUNCTION_WITHSTACK(start_spider_mk1_evk,
> >> MY_STACK_TOP,
> >>>>>> r0, r1,
> >>>>>>> +r2) {
> >>>>>>> +       extern char __dtb_spider_mk1_evk_start[];
> >>>>>>> +
> >>>>>>> +       spider_lowlevel_init();
> >>>>>>> +
> >>>>>>> +       relocate_to_current_adr();
> >>>>>>> +       setup_c();
> >>>>>>> +
> >>>>>>> +       pbl_set_putc(spider_serial_putc, (void *)BASE_ADDR);
> >>>>>>> +
> >>>>>>> +       barebox_arm_entry(GPRAM_ADDR, SZ_2M,
> >>>>>>> +__dtb_spider_mk1_evk_start); }
> >>>>>>> diff --git a/arch/arm/configs/spider_defconfig
> >>>>>> b/arch/arm/configs/spider_defconfig
> >>>>>>> new file mode 100644
> >>>>>>> index 000000000000..c91bb889d97f
> >>>>>>> --- /dev/null
> >>>>>>> +++ b/arch/arm/configs/spider_defconfig
> >>>>>>> @@ -0,0 +1,8 @@
> >>>>>>> +CONFIG_ARCH_SPIDER=y
> >>>>>>> +CONFIG_MACH_SPIDER_MK1_EVK=y
> >>>>>>> +CONFIG_BOARD_ARM_GENERIC_DT=y
> >>>>>>> +CONFIG_MALLOC_TLSF=y
> >>>>>>> +CONFIG_KALLSYMS=y
> >>>>>>> +CONFIG_RELOCATABLE=y
> >>>>>>> +CONFIG_CONSOLE_ALLOW_COLOR=y
> >>>>>>> +CONFIG_PBL_CONSOLE=y
> >>>>>>> diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile index
> >>>>>> 98f4c4e0194b..94b304d4878f 100644
> >>>>>>> --- a/arch/arm/dts/Makefile
> >>>>>>> +++ b/arch/arm/dts/Makefile
> >>>>>>> @@ -134,6 +134,7 @@ lwl-$(CONFIG_MACH_SOLIDRUN_CUBOX)
> +=
> >>>> dove-
> >>>>>> cubox-bb.dtb.o
> >>>>>>>  lwl-$(CONFIG_MACH_SOLIDRUN_MICROSOM) += imx6dl-
> >>>>>> hummingboard.dtb.o imx6q-hummingboard.dtb.o \
> >>>>>>>                                 imx6dl-hummingboard2.dtb.o imx6q-
> >>>>>> hummingboard2.dtb.o \
> >>>>>>>                                 imx6q-h100.dtb.o
> >>>>>>> +lwl-$(CONFIG_MACH_SPIDER_MK1_EVK) += spider-mk1-evk.dtb.o
> >>>>>>>  lwl-$(CONFIG_MACH_SKOV_IMX6) += imx6s-skov-imx6.dtb.o
> imx6dl-
> >>>> skov-
> >>>>>> imx6.dtb.o imx6q-skov-imx6.dtb.o
> >>>>>>>  lwl-$(CONFIG_MACH_SKOV_ARM9CPU) += at91-skov-
> arm9cpu.dtb.o
> >>>>>>>  lwl-$(CONFIG_MACH_SEEED_ODYSSEY) += stm32mp157c-
> >> odyssey.dtb.o
> >>>>>> diff --git a/arch/arm/dts/spider-mk1-evk.dts b/arch/arm/dts/spider-
> >> mk1-
> >>>>>> evk.dts new file mode 100644 index 000000000000..b8081cb85bf8
> >>>>>>> --- /dev/null
> >>>>>>> +++ b/arch/arm/dts/spider-mk1-evk.dts
> >>>>>>> @@ -0,0 +1,10 @@
> >>>>>>> +// SPDX-License-Identifier: GPL-2.0 OR X11
> >>>>>>> +
> >>>>>>> +/dts-v1/;
> >>>>>>> +
> >>>>>>> +#include "spider-mk1.dtsi"
> >>>>>>> +
> >>>>>>> +/ {
> >>>>>>> +       model = "Pliops Spider MK-I EVK";
> >>>>>>> +       compatible = "pliops,spider-mk1-evk"; };
> >>>>>>> diff --git a/arch/arm/dts/spider-mk1.dtsi b/arch/arm/dts/spider-
> >> mk1.dtsi
> >>>>>> new file mode 100644 index 000000000000..d4613848169d
> >>>>>>> --- /dev/null
> >>>>>>> +++ b/arch/arm/dts/spider-mk1.dtsi
> >>>>>>> @@ -0,0 +1,46 @@
> >>>>>>> +// SPDX-License-Identifier: GPL-2.0 OR X11
> >>>>>>> +
> >>>>>>> +/ {
> >>>>>>> +       #address-cells = <2>;
> >>>>>>> +       #size-cells = <2>;
> >>>>>>> +
> >>>>>>> +       chosen {
> >>>>>>> +               stdout-path = &uart0;
> >>>>>>> +       };
> >>>>>>> +
> >>>>>>> +       aliases {
> >>>>>>> +               serial0 = &uart0;
> >>>>>>> +       };
> >>>>>>> +
> >>>>>>> +       cpus {
> >>>>>>> +               #address-cells = <1>;
> >>>>>>> +               #size-cells = <0>;
> >>>>>>> +
> >>>>>>> +               cpu0: cpu@0 {
> >>>>>>> +                       device_type = "cpu";
> >>>>>>> +                       compatible = "arm,cortex-a53";
> >>>>>>> +                       reg = <0x0>;
> >>>>>>> +               };
> >>>>>>> +       };
> >>>>>>> +
> >>>>>>> +       memory@1000000 {
> >>>>>>> +               reg = <0x0 0x1000000 0x0 0x400000>; /* 128M */
> >>>>>>> +               device_type = "memory";
> >>>>>>> +       };
> >>>>>>> +
> >>>>>>> +       soc {
> >>>>>>> +               #address-cells = <2>;
> >>>>>>> +               #size-cells = <2>;
> >>>>>>> +               ranges;
> >>>>>>> +
> >>>>>>> +               sram@c000000000 {
> >>>>>>> +                       compatible = "mmio-sram";
> >>>>>>> +                       reg = <0xc0 0x0 0x0 0x400000>;
> >>>>>>> +               };
> >>>>>>> +
> >>>>>>> +               uart0: serial@d000307000 {
> >>>>>>> +                       compatible = "pliops,spider-uart";
> >>>>>>> +                       reg = <0xd0 0x307000 0 0x1000>;
> >>>>>>> +               };
> >>>>>>> +       };
> >>>>>>> +};
> >>>>>>> diff --git a/arch/arm/mach-spider/Kconfig b/arch/arm/mach-
> >>>> spider/Kconfig
> >>>>>> new file mode 100644 index 000000000000..6d2f888a5fd8
> >>>>>>> --- /dev/null
> >>>>>>> +++ b/arch/arm/mach-spider/Kconfig
> >>>>>>> @@ -0,0 +1,16 @@
> >>>>>>> +# SPDX-License-Identifier: GPL-2.0-only
> >>>>>>> +
> >>>>>>> +if ARCH_SPIDER
> >>>>>>> +
> >>>>>>> +config ARCH_SPIDER_MK1
> >>>>>>> +       bool
> >>>>>>> +       select CPU_V8
> >>>>>>> +       help
> >>>>>>> +         The first Cortex-A53-based SoC of the spider family.
> >>>>>>> +         This symbol is invisble and select by boards
> >>>>>>> +
> >>>>>>> +config MACH_SPIDER_MK1_EVK
> >>>>>>> +       bool "Pliops Spider Reference Design Board"
> >>>>>>> +       select ARCH_SPIDER_MK1
> >>>>>>> +
> >>>>>>> +endif
> >>>>>>> diff --git a/arch/arm/mach-spider/Makefile b/arch/arm/mach-
> >>>>>> spider/Makefile new file mode 100644 index
> >>>> 000000000000..b08c4a93ca27
> >>>>>>> --- /dev/null
> >>>>>>> +++ b/arch/arm/mach-spider/Makefile
> >>>>>>> @@ -0,0 +1 @@
> >>>>>>> +lwl-y += lowlevel.o
> >>>>>>> diff --git a/arch/arm/mach-spider/lowlevel.c b/arch/arm/mach-
> >>>>>> spider/lowlevel.c new file mode 100644 index
> >>>>>> 000000000000..5d62ef0f39e5
> >>>>>>> --- /dev/null
> >>>>>>> +++ b/arch/arm/mach-spider/lowlevel.c
> >>>>>>> @@ -0,0 +1,14 @@
> >>>>>>> +// SPDX-License-Identifier:     GPL-2.0+
> >>>>>>> +
> >>>>>>> +#include <linux/types.h>
> >>>>>>> +#include <mach/spider/lowlevel.h>
> >>>>>>> +#include <asm/barebox-arm-head.h>
> >>>>>>> +
> >>>>>>> +void spider_lowlevel_init(void)
> >>>>>>> +{
> >>>>>>> +       arm_cpu_lowlevel_init();
> >>>>>>> +       /*
> >>>>>>> +        * not yet relocated, only do writel/readl for stuff that's
> >>>>>>> +        * critical to run early. No global variables allowed.
> >>>>>>> +        */
> >>>>>>> +}
> >>>>>>> diff --git a/images/Makefile b/images/Makefile index
> >>>>>> c93f9e268978..97521e713228 100644
> >>>>>>> --- a/images/Makefile
> >>>>>>> +++ b/images/Makefile
> >>>>>>> @@ -150,6 +150,7 @@ include $(srctree)/images/Makefile.mxs
> >> include
> >>>>>> $(srctree)/images/Makefile.omap3  include
> >>>>>> $(srctree)/images/Makefile.rockchip
> >>>>>>>  include $(srctree)/images/Makefile.socfpga
> >>>>>>> +include $(srctree)/images/Makefile.spider
> >>>>>>>  include $(srctree)/images/Makefile.stm32mp
> >>>>>>>  include $(srctree)/images/Makefile.tegra  include
> >>>>>> $(srctree)/images/Makefile.versatile
> >>>>>>> diff --git a/images/Makefile.spider b/images/Makefile.spider new file
> >>>> mode
> >>>>>> 100644 index 000000000000..c32f2762df04
> >>>>>>> --- /dev/null
> >>>>>>> +++ b/images/Makefile.spider
> >>>>>>> @@ -0,0 +1,5 @@
> >>>>>>> +# SPDX-License-Identifier: GPL-2.0-only
> >>>>>>> +
> >>>>>>> +pblb-$(CONFIG_MACH_SPIDER_MK1_EVK) +=
> start_spider_mk1_evk
> >>>>>>> +FILE_barebox-spider-mk1-evk.img = start_spider_mk1_evk.pblb
> >>>>>>> +image-$(CONFIG_MACH_SPIDER_MK1_EVK) += barebox-spider-
> mk1-
> >>>>>> evk.img
> >>>>>>> diff --git a/include/mach/spider/lowlevel.h
> >>>>>> b/include/mach/spider/lowlevel.h new file mode 100644 index
> >>>>>> 000000000000..6e0ce1c77f7e
> >>>>>>> --- /dev/null
> >>>>>>> +++ b/include/mach/spider/lowlevel.h
> >>>>>>> @@ -0,0 +1,7 @@
> >>>>>>> +/* SPDX-License-Identifier: GPL-2.0+ */ #ifndef __MACH_SPIDER_H_
> >>>>>>> +#define __MACH_SPIDER_H_
> >>>>>>> +
> >>>>>>> +void spider_lowlevel_init(void);
> >>>>>>> +
> >>>>>>> +#endif
> >>>>>>> --
> >>>>>>> 2.38.4
> >>>>>>>
> >>>>>>>
> >>>>>>
> >>>>>> --
> >>>>>> Pengutronix e.K.                           |                             |
> >>>>>> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
> >>>>>> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0
> |
> >>>>>> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-
> 5555
> >> |
> >>>>>
> >>>>
> >>>> --
> >>>> Pengutronix e.K.                           |                             |
> >>>> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
> >>>> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
> >>>> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555
> |
> >>>
> >>
> >> --
> >> Pengutronix e.K.                           |                             |
> >> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
> >> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
> >> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
> >
> 
> --
> Pengutronix e.K.                           |                             |
> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |