Re: [PATCH u-boot-marvell 00/13] Yet another kwboot improvements

Stefan Roese
2021-10-27T05:09:55Z

On 26.10.21 20:48, Pali Rohár wrote:
> On Tuesday 26 October 2021 16:21:02 Stefan Roese wrote:
>> On 26.10.21 14:40, Pali Rohár wrote:
>>> My another guess there could be a problem is usage of stack. Maybe it is
>>> possible that register with stack pointer is not initialized after the
>>> full transfer when going to execute main image. Same arm baudrate change
>>> code is used after the SPL and before main U-Boot, and the first
>>> instruction is "push". Maybe modifying the arm code to not use stack
>>> when switching the baudrate back to 115200 could also help. I will look
>>> at it.
>>
>> Thanks.
>
> Here is dirty hack patch which completely disable calling code for
> changing baudrate back to 115200 on ARM side:
>
> diff --git a/tools/kwboot.c b/tools/kwboot.c
> index 5f4ff673972e..00d58a239c71 100644
> --- a/tools/kwboot.c
> +++ b/tools/kwboot.c
> @@ -1070,17 +1070,17 @@ kwboot_xmodem(int tty, const void *_img, size_t size, int baudrate)
> return rc;
>
> if (baudrate) {
> - char buf[sizeof(kwb_baud_magic)];
> -
> - kwboot_printv("Waiting 1s for baudrate change magic\n");
> - rc = kwboot_tty_recv(tty, buf, sizeof(buf), 1000);
> - if (rc)
> - return rc;
> -
> - if (memcmp(buf, kwb_baud_magic, sizeof(buf))) {
> - errno = EPROTO;
> - return -1;
> - }
> +// char buf[sizeof(kwb_baud_magic)];
> +//
> +// kwboot_printv("Waiting 1s for baudrate change magic\n");
> +// rc = kwboot_tty_recv(tty, buf, sizeof(buf), 1000);
> +// if (rc)
> +// return rc;
> +//
> +// if (memcmp(buf, kwb_baud_magic, sizeof(buf))) {
> +// errno = EPROTO;
> +// return -1;
> +// }
>
> kwboot_printv("\nChanging baudrate back to 115200 Bd\n\n");
> rc = kwboot_tty_change_baudrate(tty, 115200);
> @@ -1551,8 +1551,8 @@ kwboot_img_patch(void *img, size_t *size, int baudrate)
> * This code is appended after the data part of the image and
> * execaddr is changed to execute this code before U-Boot proper.
> */
> - kwboot_printv("Injecting code for changing baudrate back\n");
> - _copy_baudrate_change_code(hdr, size, 1, baudrate, 115200);
> +// kwboot_printv("Injecting code for changing baudrate back\n");
> +// _copy_baudrate_change_code(hdr, size, 1, baudrate, 115200);

I do have this here in my version as well:

/* Update the 32-bit data checksum */
*kwboot_img_csum32_ptr(img) = kwboot_img_csum32(img);

/* recompute header size */
hdrsz = kwbheader_size(hdr);

So I'm using the newer version, just to be sure.

>
> /* recompute header size */
> hdrsz = kwbheader_size(hdr);
>
> As main U-Boot binary on ARM resets UART, it means that baudrate is
> properly set to 115200. Probably beginning of the U-Boot output could be
> lost but at least console should start.
>
> Could you try this patch if it starts working now?

Okay, applied this patch and and booting with different baudrates works
on this board again (tested with 230400):

96 %
[......................................................................]
98 %
[......................................................................]
99 % [................
]
Done
Finishing transfer

Changing baudrate back to 115200 Bd

[Type Ctrl-\ + c to quit]

U-Boot 2021.10-00908-gc129aa2f173a-dirty (Oct 27 2021 - 07:05:39 +0200)

SoC: MV78260-B0 at 1333 MHz
I2C: ready
DRAM: 2 GiB (667 MHz, 64-bit, ECC not enabled)
Loading Environment from SPIFlash... SF: Detected m25p128 with page size
256 Bytes, erase size 256 KiB, total 16 MiB
OK
Model: Marvell Armada XP theadorable
...

Thanks,
Stefan