Fix: Blackpill-F4 and BMP DFU

src/platforms/blackpill-f401cc/platform.h

@@ -23,7 +23,8 @@
 #ifndef PLATFORMS_BLACKPILL_F401CC_PLATFORM_H
 #define PLATFORMS_BLACKPILL_F401CC_PLATFORM_H
 
-#define PLATFORM_IDENT "(BlackPill-F401CC) "
+#define PLATFORM_IDENT      "(BlackPill-F401CC) "
+#define PLATFORM_CLOCK_FREQ RCC_CLOCK_3V3_84MHZ
 
 #include "blackpill-f4.h"
 

src/platforms/blackpill-f401ce/platform.h

@@ -23,7 +23,8 @@
 #ifndef PLATFORMS_BLACKPILL_F401CE_PLATFORM_H
 #define PLATFORMS_BLACKPILL_F401CE_PLATFORM_H
 
-#define PLATFORM_IDENT "(BlackPill-F401CE) "
+#define PLATFORM_IDENT      "(BlackPill-F401CE) "
+#define PLATFORM_CLOCK_FREQ RCC_CLOCK_3V3_84MHZ
 
 #include "blackpill-f4.h"
 

src/platforms/blackpill-f411ce/platform.h

@@ -23,7 +23,8 @@
 #ifndef PLATFORMS_BLACKPILL_F411CE_PLATFORM_H
 #define PLATFORMS_BLACKPILL_F411CE_PLATFORM_H
 
-#define PLATFORM_IDENT "(BlackPill-F411CE) "
+#define PLATFORM_IDENT      "(BlackPill-F411CE) "
+#define PLATFORM_CLOCK_FREQ RCC_CLOCK_3V3_96MHZ
 
 #include "blackpill-f4.h"
 

src/platforms/common/blackpill-f4/Makefile.inc

@@ -31,6 +31,7 @@ LDFLAGS_BOOT =              \
 ifeq ($(BMP_BOOTLOADER), 1)
 $(info  Load address 0x08004000 for BMPBootloader)
 LDFLAGS = $(LDFLAGS_BOOT) -Wl,-Ttext=0x8004000
+CFLAGS += -DAPP_START=0x08004000 -DBMP_BOOTLOADER
 CFLAGS += -DDFU_SERIAL_LENGTH=9
 else
 LDFLAGS += $(LDFLAGS_BOOT)

src/platforms/common/blackpill-f4/blackpill-f4.c

@@ -38,20 +38,21 @@
 #include <libopencm3/usb/dwc/otg_fs.h>
 
 jmp_buf fatal_error_jmpbuf;
-extern uint32_t _ebss; // NOLINT(bugprone-reserved-identifier,cert-dcl37-c,cert-dcl51-cpp)
+volatile uint32_t magic[2] __attribute__((section(".noinit")));
 
 void platform_init(void)
 {
-	volatile uint32_t *magic = (uint32_t *)&_ebss;
 	/* Enable GPIO peripherals */
 	rcc_periph_clock_enable(RCC_GPIOA);
 	rcc_periph_clock_enable(RCC_GPIOC);
 	rcc_periph_clock_enable(RCC_GPIOB);
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Warray-bounds"
+#ifndef BMP_BOOTLOADER
+	/* Blackpill board has a floating button on PA0. Pull it up and use as active-low. */
+	gpio_mode_setup(GPIOA, GPIO_MODE_INPUT, GPIO_PUPD_PULLUP, GPIO0);
+
 	/* Check the USER button */
-	if (gpio_get(GPIOA, GPIO0) || (magic[0] == BOOTMAGIC0 && magic[1] == BOOTMAGIC1)) {
+	if (!gpio_get(GPIOA, GPIO0) || (magic[0] == BOOTMAGIC0 && magic[1] == BOOTMAGIC1)) {
 		magic[0] = 0;
 		magic[1] = 0;
 		/* Assert blue LED as indicator we are in the bootloader */
@@ -66,16 +67,16 @@ void platform_init(void)
 		SYSCFG_MEMRM |= 1U;
 		scb_reset_core();
 	}
-#pragma GCC diagnostic pop
-	rcc_clock_setup_pll(&rcc_hse_25mhz_3v3[RCC_CLOCK_3V3_84MHZ]);
+#endif
+	rcc_clock_setup_pll(&rcc_hse_25mhz_3v3[PLATFORM_CLOCK_FREQ]);
 
 	/* Enable peripherals */
 	rcc_periph_clock_enable(RCC_OTGFS);
 	rcc_periph_clock_enable(RCC_CRC);
 
-	/* Set up USB Pins and alternate function */
-	gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO9 | GPIO11 | GPIO12);
-	gpio_set_af(GPIOA, GPIO_AF10, GPIO9 | GPIO10 | GPIO11 | GPIO12);
+	/* Set up DM/DP pins. PA9/PA10 are not routed to USB-C. */
+	gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO11 | GPIO12);
+	gpio_set_af(GPIOA, GPIO_AF10, GPIO11 | GPIO12);
 
 	GPIOA_OSPEEDR &= 0x3c00000cU;
 	GPIOA_OSPEEDR |= 0x28000008U;
@@ -130,19 +131,18 @@ const char *platform_target_voltage(void)
 	return NULL;
 }
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Warray-bounds"
-
+/*
+ * Write the bootloader flag and reboot.
+ * The platform_init() will see this and reboot a second time into ST BootROM.
+ * If BMPBootloader is enabled, then it will see this and initialize its DFU.
+ */
 void platform_request_boot(void)
 {
-	uint32_t *magic = (uint32_t *)&_ebss;
 	magic[0] = BOOTMAGIC0;
 	magic[1] = BOOTMAGIC1;
 	scb_reset_system();
 }
 
-#pragma GCC diagnostic pop
-
 #ifdef PLATFORM_HAS_POWER_SWITCH
 bool platform_target_get_power(void)
 {

src/platforms/common/blackpill-f4/usbdfu.c

@@ -22,40 +22,37 @@
 #include <libopencm3/stm32/rcc.h>
 #include <libopencm3/stm32/gpio.h>
 #include <libopencm3/cm3/scb.h>
+#include <libopencm3/usb/dwc/otg_fs.h>
 
 #include "usbdfu.h"
 #include "general.h"
 #include "platform.h"
 
 uintptr_t app_address = 0x08004000U;
-extern uint32_t _ebss; // NOLINT(bugprone-reserved-identifier,cert-dcl37-c,cert-dcl51-cpp)
+volatile uint32_t magic[2] __attribute__((section(".noinit")));
 
 void dfu_detach(void)
 {
 	scb_reset_system();
 }
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Warray-bounds"
-
 int main(void)
 {
-	volatile uint32_t *magic = (uint32_t *)&_ebss;
 	rcc_periph_clock_enable(RCC_GPIOA);
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Warray-bounds"
-	if (gpio_get(GPIOA, GPIO0) || (magic[0] == BOOTMAGIC0 && magic[1] == BOOTMAGIC1)) {
+	/* Blackpill board has a floating button on PA0. Pull it up and use as active-low. */
+	gpio_mode_setup(GPIOA, GPIO_MODE_INPUT, GPIO_PUPD_PULLUP, GPIO0);
+
+	if (!gpio_get(GPIOA, GPIO0) || (magic[0] == BOOTMAGIC0 && magic[1] == BOOTMAGIC1)) {
 		magic[0] = 0;
 		magic[1] = 0;
 	} else
 		dfu_jump_app_if_valid();
-#pragma GCC diagnostic pop
 
-	rcc_clock_setup_pll(&rcc_hse_8mhz_3v3[RCC_CLOCK_3V3_168MHZ]);
+	rcc_clock_setup_pll(&rcc_hse_25mhz_3v3[PLATFORM_CLOCK_FREQ]);
 
 	/* Assert blue LED as indicator we are in the bootloader */
-	rcc_periph_clock_enable(RCC_GPIOD);
+	rcc_periph_clock_enable(RCC_GPIOC);
 	gpio_mode_setup(LED_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, LED_BOOTLOADER);
 	gpio_set(LED_PORT, LED_BOOTLOADER);
 
@@ -68,11 +65,14 @@ int main(void)
 
 	dfu_protect(false);
 	dfu_init(&USB_DRIVER);
+
+	/* https://github.com/libopencm3/libopencm3/pull/1256#issuecomment-779424001 */
+	OTG_FS_GCCFG |= OTG_GCCFG_NOVBUSSENS | OTG_GCCFG_PWRDWN;
+	OTG_FS_GCCFG &= ~(OTG_GCCFG_VBUSBSEN | OTG_GCCFG_VBUSASEN);
+
 	dfu_main();
 }
 
-#pragma GCC diagnostic pop
-
 void dfu_event(void)
 {
 }