arch/intel64: convert __nxstart to C function and move appropriate functions there

to follow the approach in other architectures

Signed-off-by: p-szafonimateusz <p-szafonimateusz@xiaomi.com>

arch/x86_64/src/intel64/CMakeLists.txt

@@ -36,6 +36,7 @@ set(SRCS
     intel64_schedulesigaction.c
     intel64_sigdeliver.c
     intel64_usestack.c
+    intel64_start.c
     intel64_handlers.c
     intel64_idle.c
     intel64_lowsetup.c

arch/x86_64/src/intel64/Make.defs

@@ -24,6 +24,7 @@ CMN_CSRCS += x86_64_allocateheap.c x86_64_copystate.c x86_64_exit.c
 CMN_CSRCS += x86_64_getintstack.c x86_64_mdelay.c x86_64_initialize.c
 CMN_CSRCS += x86_64_modifyreg8.c x86_64_modifyreg16.c x86_64_modifyreg32.c
 CMN_CSRCS += x86_64_nputs.c x86_64_switchcontext.c x86_64_udelay.c
+
 CMN_CSRCS += intel64_createstack.c intel64_initialstate.c intel64_irq.c
 CMN_CSRCS += intel64_map_region.c intel64_regdump.c intel64_releasestack.c
 CMN_CSRCS += intel64_rtc.c intel64_restore_auxstate.c intel64_savestate.c
@@ -33,7 +34,7 @@ CMN_CSRCS += intel64_sigdeliver.c intel64_usestack.c x86_64_tcbinfo.c
 # Required Intel64 files
 
 CHIP_ASRCS  = intel64_saveusercontext.S intel64_fullcontextrestore.S intel64_vectors.S intel64_head.S
-CHIP_CSRCS  = intel64_handlers.c intel64_idle.c intel64_lowsetup.c
+CHIP_CSRCS  = intel64_start.c intel64_handlers.c intel64_idle.c intel64_lowsetup.c
 CHIP_CSRCS += intel64_serial.c intel64_rng.c intel64_check_capability.c
 
 # Configuration-dependent intel64 files

arch/x86_64/src/intel64/intel64.h

@@ -72,7 +72,7 @@ extern "C"
  * Name: intel64_lowsetup
  *
  * Description:
- *   Called at the very beginning of _start.
+ *   Called at the very beginning of _nxstart.
  *   Performs low level initializationincluding setup of the console UART.
  *   This UART done early so that the serial console is available for
  *   debugging very early in the boot sequence.

arch/x86_64/src/intel64/intel64_head.S

@@ -45,12 +45,11 @@
  ****************************************************************************/
 
 	.global    __pmode_entry                   /* The 32bit protected mode entry */
-	.global    __nxstart
 	.global    __enable_sse_avx
 	.global    __enable_pcid
 	.global    __revoke_low_memory
+	.global    __nxstart                       /* __nxstart is defined elsewhere */
 	.global    nx_start                        /* nx_start is defined elsewhere */
-	.global    up_lowsetup                     /* up_lowsetup is defined elsewhere */
 	.global    g_idle_topstack                 /* The end of the idle stack, the start of the heap */
 	.global    mb_info_struct
 	.global    mb_magic
@@ -267,28 +266,7 @@ start64:
     mov     %ax,    %fs
     mov     %ax,    %gs
 
-    /* Finally, we can start the OS */
+    /* Clear out bss section */
-    movabs  $__nxstart,   %rbx
-    jmp     *%rbx
-    .size   __pmode_entry, . - __pmode_entry
-
-/****************************************************************************
- * Name: __nxstart
- *
- * Description:
- *   Do low-level initialization and call nx_start
- *
- ****************************************************************************/
-
-    .section .text, "ax"
-    .type   __nxstart, @function
-
-__nxstart:
-    /* We are now in high memory, will revoke the lower 128MB memory mapping
-     * in lowsetup
-     */
-
-    /* clear out bss section */
     movabs  $_sbss, %rbx
     movabs  $_ebss, %rdx
 clear_bss:
@@ -301,20 +279,16 @@ clear_bss:
     movabs  $g_idle_topstack,    %rbx
     mov     (%rbx),   %rsp
 
-    /* Initialize and start NuttX */
+    /* We use jmp instruction below which doesn't push 1 byte on stack, so we
-    call    up_lowsetup                     /* Low-level, pre-OS initialization */
+     * have to push a dummy value here, otherwise SSE instructions calledd
+     * during initialization will fail.
+     */
+    pushq   $0
 
-    call    nx_start                        /* Start NuttX */
+    /* Finally, we can start the OS */
-
+    movabs  $__nxstart,   %rbx
-    /* NuttX will not return */
+    jmp     *%rbx
-    /* We should never end up here */
+    .size   __pmode_entry, . - __pmode_entry
-    /* If we really do, then we are doomed, halting the processor for ever */
-
-    cli
-hang:
-    hlt                                    /* Halt machine should NuttX return */
-    jmp    hang
-    .size    __nxstart, . - __nxstart
 
 /****************************************************************************
  * Name: __revoke_low_memory
@@ -324,6 +298,7 @@ hang:
  *
  ****************************************************************************/
 
+	.section .text, "ax"
 	.type   __revoke_low_memory, @function
 
 __revoke_low_memory:

arch/x86_64/src/intel64/intel64_lowsetup.c

@@ -25,8 +25,6 @@
 #include <nuttx/config.h>
 
 #include <nuttx/arch.h>
-#include <arch/board/board.h>
-#include <arch/multiboot2.h>
 
 #include "x86_64_internal.h"
 
@@ -53,77 +51,24 @@ volatile uint64_t *pt;
 volatile struct ist_s *ist64;
 volatile struct gdt_entry_s *gdt64;
 
-/* This holds information passed by the multiboot2 bootloader */
-
-uint32_t mb_magic __attribute__((section(".loader.bss")));
-uint32_t mb_info_struct __attribute__((section(".loader.bss")));
-
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
 
-#ifdef CONFIG_ARCH_MULTIBOOT2
-/****************************************************************************
- * Name: x86_64_mb2_config
- *
- * Description:
- *   Parse multiboot2 info.
- *
- ****************************************************************************/
-
-static void x86_64_mb2_config(void)
-{
-  struct multiboot_tag *tag;
-
-  /* Check that we were actually booted by a mulitboot2 bootloader */
-
-  if (mb_magic != MULTIBOOT2_BOOTLOADER_MAGIC)
-    {
-      return;
-    }
-
-  for (tag = (struct multiboot_tag *)(uintptr_t)(mb_info_struct + 8);
-       tag->type != MULTIBOOT_TAG_TYPE_END;
-       tag = (struct multiboot_tag *)((uint8_t *)tag +
-                                      ((tag->size + 7) & ~7)))
-    {
-      switch (tag->type)
-        {
-          case MULTIBOOT_TAG_TYPE_EFI64:
-            {
-              break;
-            }
-
-#ifdef CONFIG_MULTBOOT2_FB_TERM
-          case MULTIBOOT_TAG_TYPE_FRAMEBUFFER:
-            {
-              x86_64_mb2_fbinitialize(
-                (struct multiboot_tag_framebuffer *)tag);
-              break;
-            }
-#endif
-
-          default:
-            break;
-        }
-    }
-}
-#endif
-
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Name: up_lowsetup
+ * Name: intel64_lowsetup
  *
  * Description:
- *   Called from intel64_head BEFORE starting the operating system in order
+ *   Called from __nxstart BEFORE starting the operating system in order
  *   perform any necessary, early initialization.
  *
  ****************************************************************************/
 
-void up_lowsetup(void)
+void intel64_lowsetup(void)
 {
   /* we should be in long mode at this point */
 
@@ -148,30 +93,7 @@ void up_lowsetup(void)
 
   x86_64_check_and_enable_capability();
 
-#ifdef CONFIG_ARCH_MULTIBOOT2
-  /* Handle multiboot2 info */
-
-  x86_64_mb2_config();
-#endif
-
   /* Revoke the lower memory */
 
   __revoke_low_memory();
-
-  /* perform board-specific initializations */
-
-  x86_64_boardinitialize();
-
-#ifdef USE_EARLYSERIALINIT
-  /* Early serial driver initialization */
-
-  x86_64_earlyserialinit();
-#endif
-
-  x86_64_timer_calibrate_freq();
-
-#ifdef CONFIG_LIB_SYSCALL
-  enable_syscall();
-#endif
 }
-

arch/x86_64/src/intel64/intel64_start.c

@@ -0,0 +1,143 @@
+/****************************************************************************
+ * arch/x86_64/src/intel64/intel64_start.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <nuttx/init.h>
+
+#include <arch/board/board.h>
+#include <arch/multiboot2.h>
+
+#include "x86_64_internal.h"
+#include "intel64.h"
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/* This holds information passed by the multiboot2 bootloader */
+
+uint32_t mb_magic __attribute__((section(".loader.bss")));
+uint32_t mb_info_struct __attribute__((section(".loader.bss")));
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+#ifdef CONFIG_ARCH_MULTIBOOT2
+/****************************************************************************
+ * Name: x86_64_mb2_config
+ *
+ * Description:
+ *   Parse multiboot2 info.
+ *
+ ****************************************************************************/
+
+static void x86_64_mb2_config(void)
+{
+  struct multiboot_tag *tag;
+
+  /* Check that we were actually booted by a multiboot2 bootloader */
+
+  if (mb_magic != MULTIBOOT2_BOOTLOADER_MAGIC)
+    {
+      return;
+    }
+
+  for (tag = (struct multiboot_tag *)(uintptr_t)(mb_info_struct + 8);
+       tag->type != MULTIBOOT_TAG_TYPE_END;
+       tag = (struct multiboot_tag *)((uint8_t *)tag +
+                                      ((tag->size + 7) & ~7)))
+    {
+      switch (tag->type)
+        {
+          case MULTIBOOT_TAG_TYPE_EFI64:
+            {
+              break;
+            }
+
+#ifdef CONFIG_MULTBOOT2_FB_TERM
+          case MULTIBOOT_TAG_TYPE_FRAMEBUFFER:
+            {
+              x86_64_mb2_fbinitialize(
+                (struct multiboot_tag_framebuffer *)tag);
+              break;
+            }
+#endif
+
+          default:
+            break;
+        }
+    }
+}
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: __nxstart
+ *
+ * Description:
+ *   Do low-level initialization and call nx_start.
+ *
+ ****************************************************************************/
+
+void __nxstart(void)
+{
+  /* Low-level, pre-OS initialization */
+
+  intel64_lowsetup();
+
+#ifdef CONFIG_ARCH_MULTIBOOT2
+  /* Handle multiboot2 info */
+
+  x86_64_mb2_config();
+#endif
+
+  /* perform board-specific initializations */
+
+  x86_64_boardinitialize();
+
+#ifdef USE_EARLYSERIALINIT
+  /* Early serial driver initialization */
+
+  x86_64_earlyserialinit();
+#endif
+
+  x86_64_timer_calibrate_freq();
+
+#ifdef CONFIG_LIB_SYSCALL
+  enable_syscall();
+#endif
+
+  /* Start NuttX */
+
+  nx_start();
+
+  /* Shouldn't get here */
+
+  for (; ; );
+}