arch/armv7: unifying boot flow for armv7-a/r

This attempts to unify the boot flow of armv7-a and armv7-r so that nx_start() is kicked by C-level arm_boot functions directly. Signed-off-by: Yanfeng Liu <[email protected]>
apache · Jan 21, 2025 · e5e3af5 · e5e3af5
1 parent de4135a
commit e5e3af5
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Showing 2 changed files with 10 additions and 22 deletions.
diff --git a/arch/arm/src/armv7-a/arm_head.S b/arch/arm/src/armv7-a/arm_head.S
@@ -682,25 +682,11 @@ __cpu0_start:
 	bl		arm_data_initialize
 #endif
 
-	/* Perform early C-level, platform-specific initialization.  Logic
-	 * within arm_boot() must configure SDRAM and call arm_data_initialize().
-	 */
+	/* C-level arm_boot() which calls nx_start() and never returns. */
 
+	mov		lr, #0     /* LR = return address (none) */
 	bl		arm_boot
 
-	/* finish busy wait */
-
-#ifdef CONFIG_ARMV7A_SMP_BUSY_WAIT
-	ldr		r0, =CONFIG_ARMV7A_SMP_BUSY_WAIT_FLAG_ADDR
-	mov		r1, #1
-	str		r1, [r0]
-	dsb		sy
-#endif
-
-	/* Finally branch to the OS entry point */
-
-	mov		lr, #0				/* LR = return address (none) */
-	b		nx_start			/* Branch to nx_start */
 	.size	.Lvstart, .-.Lvstart
 
 /***************************************************************************

diff --git a/arch/arm/src/qemu/qemu_boot.c b/arch/arm/src/qemu/qemu_boot.c
@@ -46,9 +46,7 @@
 #  include <nuttx/sched_note.h>
 #endif
 
-#ifdef CONFIG_ARCH_ARMV7R
-#  include <nuttx/init.h>
-#endif
+#include <nuttx/init.h>
 
 #include <nuttx/syslog/syslog_rpmsg.h>
 
@@ -108,11 +106,15 @@ void arm_boot(void)
   syslog_rpmsg_init_early(g_syslog_rpmsg_buf, sizeof(g_syslog_rpmsg_buf));
 #endif
 
-#ifdef CONFIG_ARCH_ARMV7R
-  /* dont return per armv7-r/arm_head.S design */
+#ifdef CONFIG_ARM_SMP_BUSY_WAIT
+  uint32_t *address = (uint32_t *)CONFIG_ARM_SMP_BUSY_WAIT_FLAG_ADDR;
+  *address = 1;
+  up_flush_dcache((uintptr_t)address, (uintptr_t)address + sizeof(address));
+#endif
+
+  /* jump to nx_start */
 
   nx_start();
-#endif
 }
 
 #if defined(CONFIG_ARM_PSCI) && defined(CONFIG_SMP)