[v3,3/5] grub2: enable support for arm and aarch64 targets

Message ID 20180926223719.12604-4-nunes.erico@gmail.com
State Accepted
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Series
  • grub2: add support for arm and aarch64
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Commit Message

Erico Nunes Sept. 26, 2018, 10:37 p.m.
This commit enables the arm-uboot, arm-efi and aarch64-efi grub2
platforms in Buildroot.

With the uboot platform, the grub2 image gets built as a u-boot image
and is loaded from u-boot through a regular "bootm". The only
requirement from the u-boot side in order to allow this is that u-boot
is built with CONFIG_API enabled. CONFIG_API seems to not be enabled by
default in most in-tree configurations, however, it seems to be
available for quite some time now. So it might be possible to use this
even on older u-boot versions. This is available only for arm (32-bit).

With the efi platform, grub2 gets built as an EFI executable. This
allows EFI firmware to find and load it similarly as it can be done for
x86_64. Also, since u-boot v2016.05, u-boot is able to load and boot an
EFI executable, so the uboot efi platform can also be used from u-boot
in recent versions. This has been enabled (mostly) by default for ARM
u-boot. efi platform is available for both arm and aarch64.

Signed-off-by: Erico Nunes <nunes.erico@gmail.com>
---
 boot/grub2/Config.in | 42 ++++++++++++++++++++++++++++++++++++++----
 boot/grub2/grub2.mk  | 21 +++++++++++++++++++++
 2 files changed, 59 insertions(+), 4 deletions(-)

Comments

Thomas Petazzoni Nov. 26, 2018, 9:03 p.m. | #1
Hello,

On Thu, 27 Sep 2018 00:37:17 +0200, Erico Nunes wrote:

> diff --git a/boot/grub2/Config.in b/boot/grub2/Config.in
> index f760f95e84..5e0e47a5bb 100644
> --- a/boot/grub2/Config.in
> +++ b/boot/grub2/Config.in
> @@ -2,10 +2,13 @@ config BR2_TARGET_GRUB2_ARCH_SUPPORTS
>  	bool
>  	default y if BR2_i386
>  	default y if BR2_x86_64
> +	default y if BR2_arm
> +	default y if BR2_aarch64

... here!

>  
>  config BR2_TARGET_GRUB2
>  	bool "grub2"
>  	depends on BR2_TARGET_GRUB2_ARCH_SUPPORTS
> +	depends on BR2_USE_MMU

I have moved this architecture dependency up here...


>  config BR2_TARGET_GRUB2_BUILTIN_MODULES
>  	string "builtin modules"
>  	default "boot linux ext2 fat squash4 part_msdos part_gpt normal biosdisk" if BR2_TARGET_GRUB2_I386_PC
>  	default "boot linux ext2 fat squash4 part_msdos part_gpt normal efi_gop" \
> -		if BR2_TARGET_GRUB2_I386_EFI || BR2_TARGET_GRUB2_X86_64_EFI
> +		if BR2_TARGET_GRUB2_I386_EFI || \
> +		BR2_TARGET_GRUB2_X86_64_EFI || \
> +		BR2_TARGET_GRUB2_ARM_EFI || \\

There was a double backslash here, I simplified to a single backslash
and also reformatted this a bit.

>  comment "grub2 needs a toolchain w/ wchar"
>  	depends on BR2_TARGET_GRUB2_ARCH_SUPPORTS
> +	depends on BR2_USE_MMU

This dependency is no longer needed, since BR2_USE_MMU is now part of
BR2_TARGET_GRUB2_ARCH_SUPPORTS.

Applied to next with those changes!

Thomas

Patch

diff --git a/boot/grub2/Config.in b/boot/grub2/Config.in
index f760f95e84..5e0e47a5bb 100644
--- a/boot/grub2/Config.in
+++ b/boot/grub2/Config.in
@@ -2,10 +2,13 @@  config BR2_TARGET_GRUB2_ARCH_SUPPORTS
 	bool
 	default y if BR2_i386
 	default y if BR2_x86_64
+	default y if BR2_arm
+	default y if BR2_aarch64
 
 config BR2_TARGET_GRUB2
 	bool "grub2"
 	depends on BR2_TARGET_GRUB2_ARCH_SUPPORTS
+	depends on BR2_USE_MMU
 	depends on BR2_USE_WCHAR
 	help
 	  GNU GRUB is a Multiboot boot loader. It was derived from
@@ -29,12 +32,14 @@  choice
 
 config BR2_TARGET_GRUB2_I386_PC
 	bool "i386-pc"
+	depends on BR2_i386 || BR2_x86_64
 	help
 	  Select this option if the platform you're targetting is a
 	  x86 or x86-64 legacy BIOS based platform.
 
 config BR2_TARGET_GRUB2_I386_EFI
 	bool "i386-efi"
+	depends on BR2_i386 || BR2_x86_64
 	help
 	  Select this option if the platform you're targetting has a
 	  32 bits EFI BIOS. Note that some x86-64 platforms use a 32
@@ -42,14 +47,38 @@  config BR2_TARGET_GRUB2_I386_EFI
 
 config BR2_TARGET_GRUB2_X86_64_EFI
 	bool "x86-64-efi"
-	depends on BR2_ARCH_IS_64
+	depends on BR2_x86_64
 	help
 	  Select this option if the platform you're targetting has a
 	  64 bits EFI BIOS.
 
+config BR2_TARGET_GRUB2_ARM_UBOOT
+	bool "arm-uboot"
+	depends on BR2_arm
+	help
+	  Select this option if the platform you're targetting is an
+	  ARM u-boot platform, and you want to boot Grub 2 as an u-boot
+	  compatible image.
+
+config BR2_TARGET_GRUB2_ARM_EFI
+	bool "arm-efi"
+	depends on BR2_arm
+	help
+	  Select this option if the platform you're targetting is an
+	  ARM platform and you want to boot Grub 2 as an EFI
+	  application.
+
+config BR2_TARGET_GRUB2_ARM64_EFI
+	bool "arm64-efi"
+	depends on BR2_aarch64
+	help
+	  Select this option if the platform you're targetting is an
+	  Aarch64 platform and you want to boot Grub 2 as an EFI
+	  application.
+
 endchoice
 
-if BR2_TARGET_GRUB2_I386_PC
+if BR2_TARGET_GRUB2_I386_PC || BR2_TARGET_GRUB2_ARM_UBOOT
 
 config BR2_TARGET_GRUB2_BOOT_PARTITION
 	string "boot partition"
@@ -60,13 +89,17 @@  config BR2_TARGET_GRUB2_BOOT_PARTITION
 	  first disk if using a legacy partition table, or 'hd0,gpt1'
 	  if using GPT partition table.
 
-endif # BR2_TARGET_GRUB2_I386_PC
+endif # BR2_TARGET_GRUB2_I386_PC || BR2_TARGET_GRUB2_ARM_UBOOT
 
 config BR2_TARGET_GRUB2_BUILTIN_MODULES
 	string "builtin modules"
 	default "boot linux ext2 fat squash4 part_msdos part_gpt normal biosdisk" if BR2_TARGET_GRUB2_I386_PC
 	default "boot linux ext2 fat squash4 part_msdos part_gpt normal efi_gop" \
-		if BR2_TARGET_GRUB2_I386_EFI || BR2_TARGET_GRUB2_X86_64_EFI
+		if BR2_TARGET_GRUB2_I386_EFI || \
+		BR2_TARGET_GRUB2_X86_64_EFI || \
+		BR2_TARGET_GRUB2_ARM_EFI || \\
+		BR2_TARGET_GRUB2_ARM64_EFI
+	default "linux ext2 fat part_msdos normal" if BR2_TARGET_GRUB2_ARM_UBOOT
 
 config BR2_TARGET_GRUB2_BUILTIN_CONFIG
 	string "builtin config"
@@ -88,4 +121,5 @@  endif # BR2_TARGET_GRUB2
 
 comment "grub2 needs a toolchain w/ wchar"
 	depends on BR2_TARGET_GRUB2_ARCH_SUPPORTS
+	depends on BR2_USE_MMU
 	depends on !BR2_USE_WCHAR
diff --git a/boot/grub2/grub2.mk b/boot/grub2/grub2.mk
index bb678ef5de..65371f0170 100644
--- a/boot/grub2/grub2.mk
+++ b/boot/grub2/grub2.mk
@@ -44,6 +44,27 @@  GRUB2_PREFIX = /EFI/BOOT
 GRUB2_TUPLE = x86_64-efi
 GRUB2_TARGET = x86_64
 GRUB2_PLATFORM = efi
+else ifeq ($(BR2_TARGET_GRUB2_ARM_UBOOT),y)
+GRUB2_IMAGE = $(BINARIES_DIR)/boot-part/grub/grub.img
+GRUB2_CFG = $(BINARIES_DIR)/boot-part/grub/grub.cfg
+GRUB2_PREFIX = ($(GRUB2_BOOT_PARTITION))/boot/grub
+GRUB2_TUPLE = arm-uboot
+GRUB2_TARGET = arm
+GRUB2_PLATFORM = uboot
+else ifeq ($(BR2_TARGET_GRUB2_ARM_EFI),y)
+GRUB2_IMAGE = $(BINARIES_DIR)/efi-part/EFI/BOOT/bootarm.efi
+GRUB2_CFG = $(BINARIES_DIR)/efi-part/EFI/BOOT/grub.cfg
+GRUB2_PREFIX = /EFI/BOOT
+GRUB2_TUPLE = arm-efi
+GRUB2_TARGET = arm
+GRUB2_PLATFORM = efi
+else ifeq ($(BR2_TARGET_GRUB2_ARM64_EFI),y)
+GRUB2_IMAGE = $(BINARIES_DIR)/efi-part/EFI/BOOT/bootaa64.efi
+GRUB2_CFG = $(BINARIES_DIR)/efi-part/EFI/BOOT/grub.cfg
+GRUB2_PREFIX = /EFI/BOOT
+GRUB2_TUPLE = arm64-efi
+GRUB2_TARGET = aarch64
+GRUB2_PLATFORM = efi
 endif
 
 # Grub2 is kind of special: it considers CC, LD and so on to be the