[PATCH 01/18] EFI stub documentation updates
Move efi-stub.txt out of x86 directory and into common directory in preparation for adding ARM EFI stub support. Signed-off-by: Roy Franz --- Documentation/efi-stub.txt | 65 Documentation/x86/efi-stub.txt | 65 arch/x86/Kconfig |2 +- 3 files changed, 66 insertions(+), 66 deletions(-) create mode 100644 Documentation/efi-stub.txt delete mode 100644 Documentation/x86/efi-stub.txt diff --git a/Documentation/efi-stub.txt b/Documentation/efi-stub.txt new file mode 100644 index 000..44e6bb6 --- /dev/null +++ b/Documentation/efi-stub.txt @@ -0,0 +1,65 @@ + The EFI Boot Stub +--- + +On the x86 platform, a bzImage can masquerade as a PE/COFF image, +thereby convincing EFI firmware loaders to load it as an EFI +executable. The code that modifies the bzImage header, along with the +EFI-specific entry point that the firmware loader jumps to are +collectively known as the "EFI boot stub", and live in +arch/x86/boot/header.S and arch/x86/boot/compressed/eboot.c, +respectively. + +By using the EFI boot stub it's possible to boot a Linux kernel +without the use of a conventional EFI boot loader, such as grub or +elilo. Since the EFI boot stub performs the jobs of a boot loader, in +a certain sense it *IS* the boot loader. + +The EFI boot stub is enabled with the CONFIG_EFI_STUB kernel option. + + + How to install bzImage.efi + +The bzImage located in arch/x86/boot/bzImage must be copied to the EFI +System Partiion (ESP) and renamed with the extension ".efi". Without +the extension the EFI firmware loader will refuse to execute it. It's +not possible to execute bzImage.efi from the usual Linux file systems +because EFI firmware doesn't have support for them. + + + Passing kernel parameters from the EFI shell + +Arguments to the kernel can be passed after bzImage.efi, e.g. + + fs0:> bzImage.efi console=ttyS0 root=/dev/sda4 + + + The "initrd=" option + +Like most boot loaders, the EFI stub allows the user to specify +multiple initrd files using the "initrd=" option. This is the only EFI +stub-specific command line parameter, everything else is passed to the +kernel when it boots. + +The path to the initrd file must be an absolute path from the +beginning of the ESP, relative path names do not work. Also, the path +is an EFI-style path and directory elements must be separated with +backslashes (\). For example, given the following directory layout, + +fs0:> + Kernels\ + bzImage.efi + initrd-large.img + + Ramdisks\ + initrd-small.img + initrd-medium.img + +to boot with the initrd-large.img file if the current working +directory is fs0:\Kernels, the following command must be used, + + fs0:\Kernels> bzImage.efi initrd=\Kernels\initrd-large.img + +Notice how bzImage.efi can be specified with a relative path. That's +because the image we're executing is interpreted by the EFI shell, +which understands relative paths, whereas the rest of the command line +is passed to bzImage.efi. diff --git a/Documentation/x86/efi-stub.txt b/Documentation/x86/efi-stub.txt deleted file mode 100644 index 44e6bb6..000 --- a/Documentation/x86/efi-stub.txt +++ /dev/null @@ -1,65 +0,0 @@ - The EFI Boot Stub ---- - -On the x86 platform, a bzImage can masquerade as a PE/COFF image, -thereby convincing EFI firmware loaders to load it as an EFI -executable. The code that modifies the bzImage header, along with the -EFI-specific entry point that the firmware loader jumps to are -collectively known as the "EFI boot stub", and live in -arch/x86/boot/header.S and arch/x86/boot/compressed/eboot.c, -respectively. - -By using the EFI boot stub it's possible to boot a Linux kernel -without the use of a conventional EFI boot loader, such as grub or -elilo. Since the EFI boot stub performs the jobs of a boot loader, in -a certain sense it *IS* the boot loader. - -The EFI boot stub is enabled with the CONFIG_EFI_STUB kernel option. - - - How to install bzImage.efi - -The bzImage located in arch/x86/boot/bzImage must be copied to the EFI -System Partiion (ESP) and renamed with the extension ".efi". Without -the extension the EFI firmware loader will refuse to execute it. It's -not possible to execute bzImage.efi from the usual Linux file systems -because EFI firmware doesn't have support for them. - - - Passing kernel parameters from the EFI shell - -Arguments to the kernel can be passed after bzImage.efi, e.g. - - fs0:> bzImage.efi console=ttyS0 root=/dev/sda4 - - - The "initrd=" option - -Like most boot loaders, the EFI stub allows the user to specify -multiple initrd files using the "initrd=" option. This is the only EFI -stub-specific command line parameter, everything
[PATCH 01/18] EFI stub documentation updates
Move efi-stub.txt out of x86 directory and into common directory in preparation for adding ARM EFI stub support. Signed-off-by: Roy Franz roy.fr...@linaro.org --- Documentation/efi-stub.txt | 65 Documentation/x86/efi-stub.txt | 65 arch/x86/Kconfig |2 +- 3 files changed, 66 insertions(+), 66 deletions(-) create mode 100644 Documentation/efi-stub.txt delete mode 100644 Documentation/x86/efi-stub.txt diff --git a/Documentation/efi-stub.txt b/Documentation/efi-stub.txt new file mode 100644 index 000..44e6bb6 --- /dev/null +++ b/Documentation/efi-stub.txt @@ -0,0 +1,65 @@ + The EFI Boot Stub +--- + +On the x86 platform, a bzImage can masquerade as a PE/COFF image, +thereby convincing EFI firmware loaders to load it as an EFI +executable. The code that modifies the bzImage header, along with the +EFI-specific entry point that the firmware loader jumps to are +collectively known as the EFI boot stub, and live in +arch/x86/boot/header.S and arch/x86/boot/compressed/eboot.c, +respectively. + +By using the EFI boot stub it's possible to boot a Linux kernel +without the use of a conventional EFI boot loader, such as grub or +elilo. Since the EFI boot stub performs the jobs of a boot loader, in +a certain sense it *IS* the boot loader. + +The EFI boot stub is enabled with the CONFIG_EFI_STUB kernel option. + + + How to install bzImage.efi + +The bzImage located in arch/x86/boot/bzImage must be copied to the EFI +System Partiion (ESP) and renamed with the extension .efi. Without +the extension the EFI firmware loader will refuse to execute it. It's +not possible to execute bzImage.efi from the usual Linux file systems +because EFI firmware doesn't have support for them. + + + Passing kernel parameters from the EFI shell + +Arguments to the kernel can be passed after bzImage.efi, e.g. + + fs0: bzImage.efi console=ttyS0 root=/dev/sda4 + + + The initrd= option + +Like most boot loaders, the EFI stub allows the user to specify +multiple initrd files using the initrd= option. This is the only EFI +stub-specific command line parameter, everything else is passed to the +kernel when it boots. + +The path to the initrd file must be an absolute path from the +beginning of the ESP, relative path names do not work. Also, the path +is an EFI-style path and directory elements must be separated with +backslashes (\). For example, given the following directory layout, + +fs0: + Kernels\ + bzImage.efi + initrd-large.img + + Ramdisks\ + initrd-small.img + initrd-medium.img + +to boot with the initrd-large.img file if the current working +directory is fs0:\Kernels, the following command must be used, + + fs0:\Kernels bzImage.efi initrd=\Kernels\initrd-large.img + +Notice how bzImage.efi can be specified with a relative path. That's +because the image we're executing is interpreted by the EFI shell, +which understands relative paths, whereas the rest of the command line +is passed to bzImage.efi. diff --git a/Documentation/x86/efi-stub.txt b/Documentation/x86/efi-stub.txt deleted file mode 100644 index 44e6bb6..000 --- a/Documentation/x86/efi-stub.txt +++ /dev/null @@ -1,65 +0,0 @@ - The EFI Boot Stub ---- - -On the x86 platform, a bzImage can masquerade as a PE/COFF image, -thereby convincing EFI firmware loaders to load it as an EFI -executable. The code that modifies the bzImage header, along with the -EFI-specific entry point that the firmware loader jumps to are -collectively known as the EFI boot stub, and live in -arch/x86/boot/header.S and arch/x86/boot/compressed/eboot.c, -respectively. - -By using the EFI boot stub it's possible to boot a Linux kernel -without the use of a conventional EFI boot loader, such as grub or -elilo. Since the EFI boot stub performs the jobs of a boot loader, in -a certain sense it *IS* the boot loader. - -The EFI boot stub is enabled with the CONFIG_EFI_STUB kernel option. - - - How to install bzImage.efi - -The bzImage located in arch/x86/boot/bzImage must be copied to the EFI -System Partiion (ESP) and renamed with the extension .efi. Without -the extension the EFI firmware loader will refuse to execute it. It's -not possible to execute bzImage.efi from the usual Linux file systems -because EFI firmware doesn't have support for them. - - - Passing kernel parameters from the EFI shell - -Arguments to the kernel can be passed after bzImage.efi, e.g. - - fs0: bzImage.efi console=ttyS0 root=/dev/sda4 - - - The initrd= option - -Like most boot loaders, the EFI stub allows the user to specify -multiple initrd files using the initrd= option. This is the only EFI -stub-specific command line parameter, everything
