u-boot.git/tools/kwboot.c, branch v2022.01

tools: kwboot: Always print kwboot version

2021-11-10T11:08:06+00:00

It is useful to see kwboot version in the boot log output for debugging
purposes.

Signed-off-by: Pali Rohár 
Reviewed-by: Stefan Roese

tools: kwboot: Fix sending Kirkwood v0 images

2021-11-10T11:08:05+00:00

Properly calculate and align image header size to xmodem block size.

Kirkwood v0 images do not have stored total size of header in header
structure itself like it is for v1 images. So kwbheader_size() calculates
size by traversing image structure itself. Aligning is done in kwboot by
putting zero padding bytes between the header and data part.

Signed-off-by: Pali Rohár 
Tested-by: Tony Dinh 
Reviewed-by: Stefan Roese

tools: kwboot: Do not send magic seq when changing baudrate back to 115200

2021-11-03T05:45:34+00:00

After successful transfer of whole image only two things can happen:
- BootROM starts execution of data block, which changes UART baudrate
  back to 115200 Bd,
- board crashes and causes CPU reset

In both cases UART baudrate is reset to the default speed. So there is
no need to send special magic sequence to inform kwboot that baudrate is
going to be reset and kwboot does not need to wait for this event and
can do it immediately after BootROM acknowledges end of xmodem transfer.

Move ARM code for sending magic sequence from main baudrate change
section to binhdr_pre section which is executed only before changing
baudrate from the default value of 115200 Bd to some new value. Remove
kwboot code waiting for magic sequence after successful xmodem transfer.

Rationale: sometimes when using very high UART speeds, magic sequence is
damaged and kwboot fails at this last stage. Removal of this magic
sequence makes booting more stable.

Data transfer protocol (xmodem) is using checksums and retransmit, so it
already deals with possible errors on transfer line.

Signed-off-by: Pali Rohár 
Signed-off-by: Marek Behún 
Reviewed-by: Stefan Roese

tools: kwboot: Do not use stack when setting baudrate back to default value

2021-11-03T05:45:27+00:00

The ARM code we inject into the image to change baudrate back to the
default value of 115200 Baud, which is run after successful UART transfer
of the whole image, cannot use stack as at this stage stack pointer is not
initialized yet.

Stack can only be used when BootROM is executing binary header, to
preserve state of registers, since BootROM expects that.

Change the ARM baudrate code to not use stack at all and put binary
header specific pre + post code (which stores and restores registers) into
separate arrays.

The baudrate change code now jumps at it's end and expects that there is
either code which returns to the BootROM or jumps to the original exec
address.

Signed-off-by: Pali Rohár 
Reviewed-by: Marek Behún 
Reviewed-by: Stefan Roese

tools: kwboot: Replace ARM mov + movt instruction pair by mov + orr

2021-11-03T05:45:27+00:00

Older Armada SoCs have custom ARMv5te compatible core which does not
support movt instruction. So replace mov + movt instruction pair used for
immediate move construction by mov + orr instructions which are supported
also by ARMv5te.

After this change kwboot ARM code should be compatible with any 32-bit ARM
core compatible by ARMv2 or new. At least GNU AS does not throw any error
or warning.

Signed-off-by: Pali Rohár 
Reviewed-by: Marek Behún 
Reviewed-by: Stefan Roese

tools: kwboot: Increase delay after changing baudrate in ARM code

2021-11-03T05:45:27+00:00

Increase loop cycles from 600000 to 2998272, which should increase delay
from 1ms to about 5ms on 1200 MHz CPU.

The Number 2998272 was chosen as the nearest value around 3000000 which can
be encoded into one ARM mov instruction. It avoids usage of movt instruction
which is not supported by ARMv5te cores.

Signed-off-by: Pali Rohár 
Reviewed-by: Marek Behún 
Reviewed-by: Stefan Roese

tools: kwboot: Do not call tcdrain() after each sent packet

2021-11-03T05:45:27+00:00

Kwboot puts each xmodem packet to kernel queue, then waits until all bytes
of that packet are transmitted over UART and then waits for xmodem reply
until it is received into kernel queue.

If some reply is received during the time we are waiting until all bytes
are transmitted, then kernel puts them into the queue and returns it to
kwboot in next read() call.

So there is no need to wait (with tcdrain() function) until all bytes from
xmodem packet are transmitted over UART, since any reply received either
during that time or after is returned to kwboot with the next read().

Therefore do not call tcdrain() after each xmodem packet sent. Instead
directly wait for any reply after putting xmodem packet into write kernel
queue.

This change could speed up xmodem transfer in case tcdrain() function waits
for a longer time.

Signed-off-by: Pali Rohár 
Reviewed-by: Marek Behún 
Reviewed-by: Stefan Roese

tools: kwboot: Fix sending retry of last header packet

2021-11-03T05:45:27+00:00

After the trasfer of last header packet, it is possible that baudrate
change pattern is received, and also that NAK byte is received so that
the packet should be sent again.

Thus we should not clear the baudrate change state when sending retry
of that packet.

Move code for initializing state variables from kwboot_xm_recv_reply()
to kwboot_xm_sendblock().

Signed-off-by: Pali Rohár 
Reviewed-by: Marek Behún 
Reviewed-by: Stefan Roese

tools: kwboot: Resend first 3 xmodem retry packets immediately

2021-11-03T05:45:27+00:00

Currently when kwboot receive some garbage reply which does not understand,
it waits 1s before it tries to resend packet again.

The most common error on UART is that receiver sees some bit flipped which
results in invalid reply.

This behavior slows down xmodem transfer over UART as basically on every
error kwboot is waiting one second.

To fix this, try to resend xmodem packet for first 3 attempts immediately
without any delay. If broken reply is received also after the 3 attempts,
continue retrying with 1s delay like it was before.

Signed-off-by: Pali Rohár 
Reviewed-by: Marek Behún 
Reviewed-by: Stefan Roese

tools: kwboot: Change retry loop from decreasing to increasing

2021-11-03T05:45:27+00:00

This patch does not change behavior of the code, just allows to implement
new changes more easily.

Signed-off-by: Pali Rohár 
Reviewed-by: Marek Behún 
Reviewed-by: Stefan Roese