From 81b5955a5c5c5b04eb334daafe1ec29821427c9e Mon Sep 17 00:00:00 2001
From: R <rqou@berkeley.edu>
Date: Mon, 6 Jul 2026 17:45:40 +0100
Subject: [PATCH] Perturb USB de-config to better match vendor behavior

This was one of many changes along the path of discovering that `wfi`
seems to just break USBD.

This change is probably not necessary, but it feels more elegant.
---
 bootloader.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/bootloader.c b/bootloader.c
index 659243c..36c0c42 100644
--- a/bootloader.c
+++ b/bootloader.c
@@ -995,8 +995,10 @@ __attribute__((naked)) int main(void) {
                         while (!(STK_SR & 1)) {}
                         STK_CTLR = 0;
                         STK_SR = 0;
-                        R16_USBD_CNTR = 0b11;
                         R32_EXTEN_CTR &= ~(1 << 1);
+                        R16_USBD_CNTR = 1;
+                        R16_USBD_ISTR = 0;
+                        R16_USBD_CNTR = 0b11;
                         if (ADDRESS_HI >> 8 == 0x20) {
                             // ram boot, go back to original clock settings
                             R32_RCC_CFGR0 = (R32_RCC_CFGR0 & ~0b11) | 0b00;