Files
wch-uf2-example/bootloader.c
T
2024-04-13 04:34:50 +01:00

427 lines
21 KiB
C

#include <stdint.h>
typedef struct USBD_descriptor {
uint32_t addr_tx;
uint32_t count_tx;
uint32_t addr_rx;
uint32_t count_rx;
} USBD_descriptor;
// USBD memory allocation:
// WARNING THIS IS A 16-bit MEMORY LMAO
// +0x00
// descriptors (two sets of two endpoints)
// +0x20
// EP 0 OUT (8 bytes)
// +0x30
// EP 0 IN (8 bytes)
// +0x40
// EP 1 OUT (64 bytes)
// +0xc0
// EP 1 IN (64 bytes)
// +0x140
// <unused>
// +0x200
// <256-byte flash page buffer>
const uint8_t USB_DEV_DESC[18] __attribute__((aligned(16))) = {
18, // bLength
1, // bDescriptorType
0x00, 0x02, // bcdUSB
0, // bDeviceClass
0, // bDeviceSubClass
0, // bDeviceProtocol
8, // bMaxPacketSize0
0x55, 0xf0, // idVendor
0x00, 0x00, // idProduct
0x00, 0x00, // bcdDevice
1, // iManufacturer
2, // iProduct
3, // iSerialNumber
1, // bNumConfigurations
};
const uint8_t USB_CONF_DESC[0x12] __attribute__((aligned(16))) = {
9, // bLength
2, // bDescriptorType
0x12, 0x00, // wTotalLength
1, // bNumInterfaces
1, // bConfigurationValue
0, // iConfiguration
0x80, // bmAttributes
250, // bMaxPower
9, // bLength
4, // bDescriptorType
0, // bInterfaceNumber
0, // bAlternateSetting
0, // bNumEndpoints
0xff, // bInterfaceClass
0xff, // bInterfaceSubClass
0xff, // bInterfaceProtocol
0, // iInterface
};
const uint8_t USB_MANUF[12] = "ArcaneNibble";
const uint8_t USB_PRODUCT[14] = "CH32V UF2 Boot";
const uint8_t HEXLUT[16] = "0123456789ABCDEF";
#define ESIG_UNIID(x) (*(volatile uint8_t*)(0x1FFFF7E8 + (x)))
// XXX manual claims 96 bits but only 64 bits seem to actually be programmed?
#define USB_DESCS ((volatile USBD_descriptor*)0x40006000)
#define USB_EP0_OUT(offs) (*(volatile uint32_t *)(0x40006020 + 2 * (offs)))
#define USB_EP0_IN(offs) (*(volatile uint32_t *)(0x40006030 + 2 * (offs)))
#define USB_EP1_OUT(offs) (*(volatile uint32_t *)(0x40006040 + 2 * (offs)))
#define USB_EP1_IN(offs) (*(volatile uint32_t *)(0x400060C0 + 2 * (offs)))
#define R32_RCC_CTLR (*(volatile uint32_t*)0x40021000)
#define R32_RCC_CFGR0 (*(volatile uint32_t*)0x40021004)
#define R32_RCC_APB2PCENR (*(volatile uint32_t*)0x40021018)
#define R32_RCC_APB1PCENR (*(volatile uint32_t*)0x4002101C)
#define R32_GPIOA_CFGLR (*(volatile uint32_t*)0x40010800)
#define R32_GPIOA_CFGHR (*(volatile uint32_t*)0x40010804)
#define R32_GPIOA_BSHR (*(volatile uint32_t*)0x40010810)
#define R16_USBD_EPR(n) (*(volatile uint16_t*)(0x40005C00 + 4 * (n)))
#define R16_USBD_CNTR (*(volatile uint16_t*)0x40005C40)
#define R16_USBD_ISTR (*(volatile uint16_t*)0x40005C44)
#define R16_USBD_DADDR (*(volatile uint16_t*)0x40005C4C)
#define R32_EXTEN_CTR (*(volatile uint32_t*)0x40023800)
// state[7:0] = addr
#define STATE_SET_ADDR 0x00
// state[15:8] = byte pos
// state[7:0] = bytes left
#define STATE_GET_DEV_DESC 0x01
#define STATE_GET_CONF_DESC 0x02
// state[15:8] = str pos *ascii*
// state[7:0] = bytes left *unicode*
#define STATE_GET_STR_MANUF 0x03
#define STATE_GET_STR_PRODUCT 0x04
#define STATE_GET_STR_SERIAL 0x05
#define STATE_CTRL_STATUS_OUT 0x06
#define STATE_CTRL_SIMPLE_IN 0x07
__attribute__((always_inline)) static inline void set_ep_mode(uint8_t ep, uint8_t stat_rx, uint8_t stat_tx, uint16_t xtra) {
uint16_t val = R16_USBD_EPR(0);
uint8_t cur_stat_rx = (val >> 12) & 0b11;
uint8_t cur_stat_tx = (val >> 4) & 0b11;
R16_USBD_EPR(0) = (val & 0b0000011000001111) | xtra | ((stat_rx ^ cur_stat_rx) << 12) | ((stat_tx ^ cur_stat_tx) << 4);
}
__attribute__((always_inline)) static inline uint32_t min(uint32_t a, uint32_t b) {
if (a <= b)
return a;
return b;
}
__attribute__((naked)) int main(void) {
// PLL setup: system clock 96 MHz
R32_EXTEN_CTR |= (1 << 4); // sneaky div2
R32_RCC_CFGR0 = (R32_RCC_CFGR0 & ~0xff0000) | (0b01101000 << 16);
R32_RCC_CTLR |= (1 << 24);
while (!(R32_RCC_CTLR & (1 << 25))) {}
R32_RCC_CFGR0 = (R32_RCC_CFGR0 & ~0b11) | 0b10;
while ((R32_RCC_CFGR0 & 0b1100) != 0b1000) {}
// As recommended in the manual, output low on these pins before enabling USB
R32_RCC_APB2PCENR |= (1 << 2);
R32_GPIOA_CFGHR = (R32_GPIOA_CFGHR & ~(0xff << 12)) | (0b00100010 << 12);
R32_GPIOA_BSHR = (1 << 27) | (1 << 28);
// Enable USB
R32_RCC_APB1PCENR |= (1 << 23);
R16_USBD_CNTR &= ~(1 << 1);
USB_DESCS[0].addr_tx = 0x30 / 2;
USB_DESCS[0].addr_rx = 0x20 / 2;
USB_DESCS[0].count_rx = (8 << 10);
USB_DESCS[1].addr_tx = 0xc0 / 2;
USB_DESCS[1].addr_rx = 0x40 / 2;
USB_DESCS[1].count_rx = (2 << 10) | (1 << 15);
// XXX because the table is at offset 0 don't bother writing this
// Attach USB
R16_USBD_CNTR &= ~(1 << 0);
R32_EXTEN_CTR |= (1 << 1);
uint32_t master_state = 0;
uint32_t active_config = 0;
while (1) {
uint32_t usb_int_status = R16_USBD_ISTR;
if (usb_int_status & (1 << 10)) {
// RESET
// set all to STALL, SETUP will come in nonetheless
R16_USBD_EPR(0) = (0b01 << 12) | (0b01 << 9) | (0b01 << 4);
R16_USBD_DADDR = 0x80;
} else if (usb_int_status & (1 << 15)) {
if ((usb_int_status & 0x1f) == 0x10) {
uint32_t ep0_status = R16_USBD_EPR(0);
if (ep0_status & (1 << 11)) {
// setup, STAT_RX and STAT_TX both now NAK
uint16_t bRequest_bmRequestType = USB_EP0_OUT(0);
uint32_t wLength = USB_EP0_OUT(6);
if (bRequest_bmRequestType == 0x0080 || bRequest_bmRequestType == 0x0081) {
// GET_STATUS
USB_EP0_IN(0) = 0;
USB_DESCS[0].count_tx = min(2, wLength);
master_state = (STATE_CTRL_SIMPLE_IN << 24);
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
} else if (bRequest_bmRequestType == 0x0500) {
// SET_ADDRESS
master_state = (STATE_SET_ADDR << 24) | USB_EP0_OUT(2);
USB_DESCS[0].count_tx = 0;
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
} else if (bRequest_bmRequestType == 0x0680) {
// GET_DESCRIPTOR
uint32_t wValue = USB_EP0_OUT(2);
if (wValue == 0x0100) {
for (int i = 0; i < 8; i+=2)
USB_EP0_IN(i) = *((uint16_t*)(&USB_DEV_DESC[i]));
if (wLength < 8) {
USB_DESCS[0].count_tx = wLength;
master_state = (STATE_GET_DEV_DESC << 24);
} else {
USB_DESCS[0].count_tx = 8;
master_state = (STATE_GET_DEV_DESC << 24) | (8 << 8) | (wLength - 8);
}
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
} else if (wValue == 0x0200) {
for (int i = 0; i < 8; i+=2)
USB_EP0_IN(i) = *((uint16_t*)(&USB_CONF_DESC[i]));
if (wLength < 8) {
USB_DESCS[0].count_tx = wLength;
master_state = (STATE_GET_CONF_DESC << 24);
} else {
USB_DESCS[0].count_tx = 8;
master_state = (STATE_GET_CONF_DESC << 24) | (8 << 8) | (wLength - 8);
}
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
} else if (wValue == 0x0300) {
// string LANGIDs
USB_EP0_IN(0) = 0x0304;
USB_EP0_IN(2) = 0x0409;
USB_DESCS[0].count_tx = min(4, wLength);
master_state = (STATE_CTRL_SIMPLE_IN << 24);
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
} else if (wValue == 0x0301) {
USB_EP0_IN(0) = 0x0300 | (sizeof(USB_MANUF) * 2 + 2);
for (int i = 0; i < 3; i++)
USB_EP0_IN(i * 2 + 2) = USB_MANUF[i];
if (wLength < 8) {
USB_DESCS[0].count_tx = wLength;
master_state = (STATE_GET_STR_MANUF << 24);
} else {
USB_DESCS[0].count_tx = 8;
master_state = (STATE_GET_STR_MANUF << 24) | (3 << 8) | (wLength - 8);
}
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
} else if (wValue == 0x0302) {
USB_EP0_IN(0) = 0x0300 | (sizeof(USB_PRODUCT) * 2 + 2);
for (int i = 0; i < 3; i++)
USB_EP0_IN(i * 2 + 2) = USB_PRODUCT[i];
if (wLength < 8) {
USB_DESCS[0].count_tx = wLength;
master_state = (STATE_GET_STR_PRODUCT << 24);
} else {
USB_DESCS[0].count_tx = 8;
master_state = (STATE_GET_STR_PRODUCT << 24) | (3 << 8) | (wLength - 8);
}
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
} else if (wValue == 0x0303) {
USB_EP0_IN(0) = 0x0300 | (24 * 2 + 2);
USB_EP0_IN(2) = HEXLUT[ESIG_UNIID(0) >> 4];
USB_EP0_IN(4) = HEXLUT[ESIG_UNIID(0) & 0xf];
USB_EP0_IN(6) = HEXLUT[ESIG_UNIID(1) >> 4];
if (wLength < 8) {
USB_DESCS[0].count_tx = wLength;
master_state = (STATE_GET_STR_SERIAL << 24);
} else {
USB_DESCS[0].count_tx = 8;
master_state = (STATE_GET_STR_SERIAL << 24) | (3 << 8) | (wLength - 8);
}
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
} else {
// bad descriptor
set_ep_mode(0, 0b01, 0b01, 0); // STALL for both
}
} else if (bRequest_bmRequestType == 0x0880) {
// GET_CONFIGURATION
USB_EP0_IN(0) = active_config;
USB_DESCS[0].count_tx = min(1, wLength);
master_state = (STATE_CTRL_SIMPLE_IN << 24);
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
} else if (bRequest_bmRequestType == 0x0900) {
// SET_CONFIGURATION
uint32_t wValue = USB_EP0_OUT(2);
if (wValue == 0 || wValue == 1) {
active_config = wValue;
USB_DESCS[0].count_tx = 0;
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
} else {
set_ep_mode(0, 0b01, 0b01, 0); // STALL for both
}
} else if (bRequest_bmRequestType == 0x0A81) {
// GET_INTERFACE
USB_EP0_IN(0) = 0;
USB_DESCS[0].count_tx = min(1, wLength);
master_state = (STATE_CTRL_SIMPLE_IN << 24);
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
} else {
// unknown
set_ep_mode(0, 0b01, 0b01, 0); // STALL for both
}
} else {
// back to stall for everything, expect SETUP
set_ep_mode(0, 0b01, 0b01, 0); // STALL for both
}
}
if ((usb_int_status & 0x1f) == 0x00) {
switch (master_state >> 24) {
case STATE_SET_ADDR:
R16_USBD_DADDR = 0x80 | (master_state & 0x7f);
master_state = 0;
// back to stall for everything, expect SETUP
set_ep_mode(0, 0b01, 0b01, 0); // STALL for both
break;
case STATE_GET_DEV_DESC:
{
uint32_t byte_pos = (master_state >> 8) & 0xff;
uint32_t bytes_left = master_state & 0xff;
if (bytes_left == 0) {
master_state = (STATE_CTRL_STATUS_OUT << 24);
set_ep_mode(0, 0b11, 0b01, 1 << 8); // ACK for OUT ZLP, STALL for IN
} else {
uint32_t bytes = bytes_left;
if (bytes > 8) bytes = 8;
if (byte_pos + bytes > sizeof(USB_DEV_DESC))
bytes = sizeof(USB_DEV_DESC) - byte_pos;
for (int i = 0; i < bytes; i+=2)
USB_EP0_IN(i) = *((uint16_t*)(&USB_DEV_DESC[byte_pos + i]));
if (bytes < 8) {
USB_DESCS[0].count_tx = bytes;
master_state = (STATE_GET_DEV_DESC << 24);
} else {
USB_DESCS[0].count_tx = 8;
master_state = (STATE_GET_DEV_DESC << 24) | ((byte_pos + 8) << 8) | (bytes_left - 8);
}
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
}
}
break;
case STATE_GET_CONF_DESC:
{
uint32_t byte_pos = (master_state >> 8) & 0xff;
uint32_t bytes_left = master_state & 0xff;
if (bytes_left == 0) {
master_state = (STATE_CTRL_STATUS_OUT << 24);
set_ep_mode(0, 0b11, 0b01, 1 << 8); // ACK for OUT ZLP, STALL for IN
} else {
uint32_t bytes = bytes_left;
if (bytes > 8) bytes = 8;
if (byte_pos + bytes > sizeof(USB_CONF_DESC))
bytes = sizeof(USB_CONF_DESC) - byte_pos;
for (int i = 0; i < bytes; i+=2)
USB_EP0_IN(i) = *((uint16_t*)(&USB_CONF_DESC[byte_pos + i]));
if (bytes < 8) {
USB_DESCS[0].count_tx = bytes;
master_state = (STATE_GET_CONF_DESC << 24);
} else {
USB_DESCS[0].count_tx = 8;
master_state = (STATE_GET_CONF_DESC << 24) | ((byte_pos + 8) << 8) | (bytes_left - 8);
}
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
}
}
break;
case STATE_GET_STR_MANUF:
{
uint32_t str_pos = (master_state >> 8) & 0xff;
uint32_t bytes_left = master_state & 0xff;
if (bytes_left == 0) {
master_state = (STATE_CTRL_STATUS_OUT << 24);
set_ep_mode(0, 0b11, 0b01, 1 << 8); // ACK for OUT ZLP, STALL for IN
} else {
// XXX this is confusing
uint32_t ascii_bytes = (bytes_left + 1) / 2;
if (ascii_bytes > 4) ascii_bytes = 4;
if (str_pos + ascii_bytes > sizeof(USB_MANUF))
ascii_bytes = sizeof(USB_MANUF) - str_pos;
for (int i = 0; i < ascii_bytes; i++)
USB_EP0_IN(i * 2) = USB_MANUF[str_pos + i];
if (ascii_bytes < 4) {
USB_DESCS[0].count_tx = bytes_left;
master_state = (STATE_GET_STR_MANUF << 24);
} else {
USB_DESCS[0].count_tx = 8;
master_state = (STATE_GET_STR_MANUF << 24) | ((str_pos + 4) << 8) | (bytes_left - 8);
}
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
}
}
break;
case STATE_GET_STR_PRODUCT:
{
uint32_t str_pos = (master_state >> 8) & 0xff;
uint32_t bytes_left = master_state & 0xff;
if (bytes_left == 0) {
master_state = (STATE_CTRL_STATUS_OUT << 24);
set_ep_mode(0, 0b11, 0b01, 1 << 8); // ACK for OUT ZLP, STALL for IN
} else {
// XXX this is confusing
uint32_t ascii_bytes = (bytes_left + 1) / 2;
if (ascii_bytes > 4) ascii_bytes = 4;
if (str_pos + ascii_bytes > sizeof(USB_PRODUCT))
ascii_bytes = sizeof(USB_PRODUCT) - str_pos;
for (int i = 0; i < ascii_bytes; i++)
USB_EP0_IN(i * 2) = USB_PRODUCT[str_pos + i];
if (ascii_bytes < 4) {
USB_DESCS[0].count_tx = bytes_left;
master_state = (STATE_GET_STR_PRODUCT << 24);
} else {
USB_DESCS[0].count_tx = 8;
master_state = (STATE_GET_STR_PRODUCT << 24) | ((str_pos + 4) << 8) | (bytes_left - 8);
}
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
}
}
break;
case STATE_GET_STR_SERIAL:
{
uint32_t str_pos = (master_state >> 8) & 0xff;
uint32_t bytes_left = master_state & 0xff;
if (bytes_left == 0) {
master_state = (STATE_CTRL_STATUS_OUT << 24);
set_ep_mode(0, 0b11, 0b01, 1 << 8); // ACK for OUT ZLP, STALL for IN
} else {
// XXX this is confusing
uint32_t ascii_bytes = (bytes_left + 1) / 2;
if (ascii_bytes > 4) ascii_bytes = 4;
if (str_pos + ascii_bytes > 24)
ascii_bytes = 24 - str_pos;
for (int i = 0; i < ascii_bytes; i++)
USB_EP0_IN(i * 2) = HEXLUT[(ESIG_UNIID((str_pos + i) / 2) >> ((1 - ((str_pos + i) % 2)) * 4)) & 0xf];
if (ascii_bytes < 4) {
USB_DESCS[0].count_tx = bytes_left;
master_state = (STATE_GET_STR_SERIAL << 24);
} else {
USB_DESCS[0].count_tx = 8;
master_state = (STATE_GET_STR_SERIAL << 24) | ((str_pos + 4) << 8) | (bytes_left - 8);
}
set_ep_mode(0, 0b01, 0b11, 0); // STALL for OUT, ACK for IN
}
}
break;
case STATE_CTRL_SIMPLE_IN:
master_state = (STATE_CTRL_STATUS_OUT << 24);
set_ep_mode(0, 0b11, 0b01, 1 << 8); // ACK for OUT ZLP, STALL for IN
break;
}
}
}
R16_USBD_ISTR = 0;
}
}