# ch32-node fw
fw for a ch32v203 node w/ w5500 ethernet

## current

### SysTick IRQ and DMA issue
[Enabling](https://git.hye.su/mira/ch32-node/src/branch/master/src/main.c#L54) the SysTick IRQ leads to a permanent hang of the socket.
  - With a 1ms IRQ interval, the hang occurs at `DHCP_ACK` during the `check_DHCP_leasedIP` -> `sendto()` [ARP request](https://git.hye.su/mira/ch32-node/src/branch/master/lib/ioLibrary_Driver/socket.c#L563).
  - With a 100ms interval, the hang occurs during the DNS request.
  - With a 1s interval it works
  - [Disabling SPI DMA](https://git.hye.su/mira/ch32-node/src/branch/master/src/w5500.c#L62) solves it (just commenting out `reg_wizchip_spiburst_cbfunc`), so it's most likely DMA related?
  - SPI DMA only works with [prescalers](https://git.hye.su/mira/ch32-node/src/branch/master/src/spi_dma.c#L140) 8 and 64?
  - Also, for some reason it needs a ~50ms delay before configuring w5500 when compiled **with** `-O0`, not needed with `-Os`...

## Diff between SPI w/ and w/o DMA:
### SPI DMA
![SPI_DMA 1](notes/SPI_DMA_no_irq_1.png)
![SPI_DMA 2](notes/SPI_DMA_no_irq_2.png)
### SPI
![SPI 1](notes/SPI_1.png)
![SPI 2](notes/SPI_2.png)

00 09 04 C0 A8 66 01 02
00 09 04 C0 A8 66 01 02 02

## ~~previous (DNS Processing)~~
solved by [patching](https://git.hye.su/mira/ch32-node/commit/259d63197e06c1a92b979490d4cd8f0fdb98f8d0#diff-6ba50689ba55dac7cfe3e9b011e594098c931e21) the korean bloatlib (`dns_makequery` in DNS.c)

w/ ch32v003fun

> Partial DNS message: `11 23 81 82 00 01 00 00 00 00 00 00 03 68 79 65 00 00 00 02 73`
> **DNS_run() failed, res = 0**

w/ WCH HAL (none-os).. I get a full response

> Receive DNS message from 192.168.102.1(53). len = 56
> Partial DNS message: `11 23 81 80 00 01 00 02 00 00 00 00 03 68 79 65 02 73 75 00 00 01 00 01 C0 0C 00 01 00 01 00 00 01 2C 00 04 68 15 33 7F C0 0C 00 01 00 01 00 00 01 2C 00 04 AC 43 B4 9A `
> Result: 172.67.180.154

`RCC_CTLR`, GPIO Registers, `SPIx_CTLR1` registers are identical

## LA

### ch32v003fun

![ch32v003fun](notes/2024-10-10-191033_1876x540_scrot.png)

```
00 00 34 11 27 01 00 00 01 00 00 00 00 00 00 03 68 79 65 00 00 00 02 73 75 00 00 00 00 01 00 01
```

- 32 bytes long
- (Post `68 79 65`): `00 00 00 02 73 75 00 00 00 00 01 00 01`

### none-os

![none-os](notes/2024-10-10-191043_1891x525_scrot.png)

```
00 00 34 11 27 01 00 00 01 00 00 00 00 00 00 03 68 79 65 02 73 75 00 00 01 00 01
```

- 27 bytes long
- (Post `68 79 65`): `02 73 75 00 00 01 00 01`
