arch/x86_64: Reimplement the NuttX32 multiboot1 wrapper.

This commit reimplemented the NuttX32 multiboot1 wrapper: 1. Fixed the issue of SMP AP booting. 2. Reduced memory copy overhead. We only need to copy .realmode section now. 3. Move the multiboot1 header to intel64_head.S. Signed-off-by: ouyangxiangzhen <[email protected]>
OceanfromXiaomi · Sep 30, 2024 · edd7d71 · edd7d71
1 parent 45f4ce8
commit edd7d71
Show file tree

Hide file tree

Showing 5 changed files with 62 additions and 45 deletions.
diff --git a/arch/x86_64/src/Makefile b/arch/x86_64/src/Makefile
@@ -136,7 +136,8 @@ endif
 
 ifeq ($(CONFIG_ARCH_MULTIBOOT1),y)
 	@echo "Generating: nuttx32 in ELF32/multiboot1"
-	$(Q) $(OBJCOPY) -R .realmode -R.note.* -O binary $(NUTTX) $(NUTTX).bin \
+	$(Q) $(OBJCOPY) -R.realmode -R.note.* -O binary $(NUTTX) $(NUTTX).bin \
+	&& $(OBJCOPY) -j.realmode -O binary $(NUTTX) $(NUTTX)_realmode.bin \
 	&& $(CC) -m32 -no-pie -nostdlib common/multiboot1.S \
 			-T common/multiboot1.ld -o $(NUTTX)32
 endif

diff --git a/arch/x86_64/src/common/multiboot1.S b/arch/x86_64/src/common/multiboot1.S
@@ -20,69 +20,37 @@
 
 /* Multiboot1 NuttX Naive Loader */
 
-.set ENTRY_ADDR,        0x100000 /* NuttX Entry Address  */
-
-.set MB_FLAG_ALIGNED,   1        /* All boot modules must be loaded aligned */
-.set MB_FLAG_MEMINFO,   2        /* Boot with memory maps passing  */
-.set MB_FLAG_VIDEO,     4        /* Enable video mode  */
-
-.set MB_FLAGS,          MB_FLAG_ALIGNED | MB_FLAG_MEMINFO
-.set MB_MAGIC,          0x1BADB002
-.set MB_CHECKSUM,       -(MB_MAGIC + MB_FLAGS)
-
 .balign 16
 .code32
 
 .globl _start
 
-.section                ".multiboot", "ax"
-header:
-.align 4
-    .long               MB_MAGIC
-    .long               MB_FLAGS
-    .long               MB_CHECKSUM
-
-    .long               0       /* header_addr  */
-    .long               0       /* load_addr */
-    .long               0       /* load_end_addr */
-    .long               0       /* bss_end_addr */
-    .long               0       /* entry_addr */
-
-    .long               0       /* Video mode type */
-    .long               1024    /* Video width */
-    .long               768     /* Video height */
-    .long               32      /* Video depth */
-
-/* NuttX bin */
+/* NuttX binary with multiboot1 header */
 
 .section                ".bin" , "ax"
 bin_start:
     .incbin             "../../../nuttx.bin"
 
-.align 8
-bin_size:
-    .long               . - bin_start
-
-/* Multiboot args */
-
 multiboot_info_struct:
     .long               0
 multiboot_magic:
     .long               0
 
-.section                ".text"
+.section                ".text" , "ax"
 _start:
 
+    /* We should manually copy .realmode section */
+
     /* Saving multiboot args */
 
     movl                %ebx, multiboot_info_struct
     movl                %eax, multiboot_magic
 
-    /* memcpy(ENTRY_ADDR, bin_start, bin_size) */
+    /* memcpy(0, realmode_start, realmode_size) */
 
-    movl                (bin_size), %ecx
-    movl                $bin_start, %esi
-    movl                $ENTRY_ADDR, %edi
+    movl                (realmode_size), %ecx
+    movl                $realmode_start, %esi
+    movl                $0, %edi
 
 copy_loop:
 
@@ -94,9 +62,23 @@ copy_loop:
     inc                 %edi
     loop                copy_loop
 
-    /* Jump to ENTRY_ADDR */
+    /* Jump to bin_start + 0x30, skip the multiboot1 header */
 
     movl                (multiboot_info_struct), %ebx
     movl                (multiboot_magic), %eax
-    movl                $ENTRY_ADDR, %ecx
+    movl                $bin_start, %ecx
+    addl                $0x30, %ecx
     jmp                 *%ecx
+
+
+/* NuttX realmode section */
+
+.section                ".realmode", "ax"
+realmode_start:
+    .incbin             "../../../nuttx_realmode.bin"
+
+.align 8
+realmode_size:
+    .long               . - realmode_start
+
+
diff --git a/arch/x86_64/src/common/multiboot1.ld b/arch/x86_64/src/common/multiboot1.ld
@@ -27,6 +27,7 @@ SECTIONS {
 		*(.multiboot)
 		*(.bin)
 		*(.text)
+		*(.realmode)
 		*(.note.gnu.*)
 	}
 }
diff --git a/arch/x86_64/src/intel64/intel64_head.S b/arch/x86_64/src/intel64/intel64_head.S
@@ -149,7 +149,7 @@ __reset_entry:
 	mov     %eax, %cr0
 
 	/* Long jump into protected mode. Hardcode the address. */
-	ljmpl   $0x8, $0x100000
+	ljmpl   $0x8, $start32_0
 
 	/* Loader GDT and GDTR */
 	.align(16)
@@ -187,14 +187,42 @@ __ap_entry:
 	mov     %eax, %cr0
 
 	/* Long jump into protected mode. Hardcode the address. */
-	ljmpl   $0x8, $0x100000
+	ljmpl   $0x8, $start32_0
 #endif
 
 /****************************************************************************
  * .text
  ****************************************************************************/
 
 	.code32
+	.section ".multiboot1", "a"
+#ifdef CONFIG_ARCH_MULTIBOOT1
+.set MB_FLAG_ALIGNED,   1       /* All boot modules must be loaded aligned */
+.set MB_FLAG_MEMINFO,   2       /* Boot with memory maps passing  */
+.set MB_FLAG_VIDEO,     4       /* Enable video mode  */
+
+.set MB_FLAGS,          MB_FLAG_ALIGNED | MB_FLAG_MEMINFO
+.set MB_MAGIC,          0x1BADB002
+.set MB_CHECKSUM,       -(MB_MAGIC + MB_FLAGS)
+
+multiboot1_header:
+	.align 4
+	.long               MB_MAGIC
+	.long               MB_FLAGS
+	.long               MB_CHECKSUM
+
+	.long               0       /* header_addr  */
+	.long               0       /* load_addr */
+	.long               0       /* load_end_addr */
+	.long               0       /* bss_end_addr */
+	.long               0       /* entry_addr */
+
+	.long               0       /* Video mode type */
+	.long               1024    /* Video width */
+	.long               768     /* Video height */
+	.long               32      /* Video depth */
+#endif
+
 	.section ".loader.text", "ax"
 
 start32_0:

diff --git a/boards/x86_64/intel64/qemu-intel64/scripts/qemu.ld b/boards/x86_64/intel64/qemu-intel64/scripts/qemu.ld
@@ -34,6 +34,11 @@ SECTIONS
     . = 0x1M;
     _kernel_physical_start = .;
 
+    .multiboot1 : {
+        . = ALIGN(8);
+        KEEP(*(.multiboot1))
+    }
+
     .loader.text : {
         . = ALIGN(8);
         *(.loader.text)