Enable booting directly to QSPI with "go" command

- Supports booting image without u-boot headers on stm32

board/emcraft/stm32f7-som/board.c

@@ -847,3 +847,32 @@ int board_late_init(void)
 	return rv;
 }
 #endif /* BOARD_LATE_INIT */
+
+#ifdef CONFIG_CMD_GO_DIRECT_JUMP
+/* Code for overriding default "go" functionality for directly
+   jumping to a memory location without return. This is needed
+   since:
+   - We are executing from QSPI
+   - RTEMS image for stm32f769i places executable code in
+     in the beginning of QSPI address range
+   - Command bootm requires u-boot header before the executable code
+*/
+
+typedef void (*jump_t)(void);
+
+static inline void __set_MSP(uint32_t topOfMainStack)
+{
+	asm volatile ("MSR msp, %0\n" : : "r" (topOfMainStack) : "sp");
+}
+
+unsigned long do_go_exec (ulong (*entry)(int, char *[]), int argc, char *argv[])
+{
+	jump_t jump;
+	jump = (jump_t) (*(uint32_t *)(entry + 4));
+	__set_MSP(*(uint32_t*) entry);
+        STM32_SYSCFG->memrmp |= SYSCFG_MEMRMP_SWP_FMC_0;
+	CM3_SCB_REGS->vtor = (uint32_t)entry;
+	jump();
+	return 0;
+}
+#endif // CONFIG_CMD_GO_DIRECT_JUMP

drivers/net/stm32_eth.c

@@ -138,11 +138,6 @@
 
 #define STM32_DMA_RBD_RCH		(1 << 14)	/* 2nd address chained*/
 
-/*
- * STM32 SYSCFG definitions
- */
-#define STM32_SYSCFG_BASE		(STM32_APB2PERIPH_BASE + 0x3800)
-
 /*
  * PMC reg fields
  */
@@ -250,19 +245,6 @@ struct stm32_mac_regs {
 #define STM32_MAC			((volatile struct stm32_mac_regs *) \
 					STM32_MAC_BASE)
 
-/*
- * SYSCFG register map
- */
-struct stm32_syscfg_regs {
-	u32	memrmp;		/* Memory remap				      */
-	u32	pmc;		/* Peripheral mode configuration	      */
-	u32	exticr[4];	/* External interrupt configuration	      */
-	u32	rsv0[2];
-	u32	cmpcr;		/* Compensation cell control		      */
-};
-#define STM32_SYSCFG			((volatile struct stm32_syscfg_regs *) \
-					STM32_SYSCFG_BASE)
-
 /*
  * STM32 ETH Normal DMA buffer descriptors
  */

include/asm-arm/arch-stm32/stm32.h

@@ -121,6 +121,24 @@ struct stm32_pwr_regs {
  */
 #define STM32F4_LTDC_BASE	(STM32_APB2PERIPH_BASE + 0x6800)
 
+/*
+ * STM32 SYSCFG definitions
+ */
+#define STM32_SYSCFG_BASE	(STM32_APB2PERIPH_BASE + 0x3800)
+
+/*
+ * SYSCFG register map
+ */
+struct stm32_syscfg_regs {
+	u32	memrmp;		/* Memory remap				      */
+	u32	pmc;		/* Peripheral mode configuration	      */
+	u32	exticr[4];	/* External interrupt configuration	      */
+	u32	rsv0[2];
+	u32	cmpcr;		/* Compensation cell control		      */
+};
+#define STM32_SYSCFG			((volatile struct stm32_syscfg_regs *) \
+					STM32_SYSCFG_BASE)
+#define SYSCFG_MEMRMP_SWP_FMC_0         (1U << 10U);
 
 /******************************************************************************
  * FIXME: get rid of this

include/configs/stm32f769i-discovery.h

@@ -311,6 +311,9 @@
 /* Enable DHCP */
 #define CONFIG_CMD_DHCP
 
+/* Directly jump with "go" */
+#define CONFIG_CMD_GO_DIRECT_JUMP
+
 /*
  * To save memory disable long help
  */
@@ -326,7 +329,12 @@
  */
 #define CONFIG_BOOTDELAY		1
 #define CONFIG_ZERO_BOOTDELAY_CHECK
+
+#ifdef CONFIG_CMD_GO_DIRECT_JUMP
+#define CONFIG_BOOTCOMMAND		"go " stringify(STM32_QSPI_BANK)
+#else
 #define CONFIG_BOOTCOMMAND		"run qspiboot || echo 'Boot from QSPI failed, run the update command'"
+#endif
 
 /* boot args and env */
 #define CONFIG_HOSTNAME			stm32f769i-disco