From: "Mika Penttilä" <mika.penttila@nextfour.com>
To: Arvind Sankar <nivedita@alum.mit.edu>, Ard Biesheuvel <ardb@kernel.org>
Cc: "linux-efi@vger.kernel.org" <linux-efi@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/5] efi/x86: Decompress at start of PE image load address
Date: Tue, 3 Mar 2020 06:28:20 +0000 [thread overview]
Message-ID: <dce7e026-ccb2-36f0-c892-83558dcc055f@nextfour.com> (raw)
In-Reply-To: <20200301230537.2247550-3-nivedita@alum.mit.edu>
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On 2.3.2020 1.05, Arvind Sankar wrote:
> When booted via PE loader, define image_offset to hold the offset of
> startup_32 from the start of the PE image, and use it as the start of
> the decompression buffer.
>
> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
> ---
> arch/x86/boot/compressed/head_32.S | 17 +++++++++++
> arch/x86/boot/compressed/head_64.S | 38 +++++++++++++++++++++++--
> drivers/firmware/efi/libstub/x86-stub.c | 12 ++++++--
> 3 files changed, 61 insertions(+), 6 deletions(-)
...
> --- a/drivers/firmware/efi/libstub/x86-stub.c
> +++ b/drivers/firmware/efi/libstub/x86-stub.c
> @@ -19,6 +19,7 @@
>
> static efi_system_table_t *sys_table;
> extern const bool efi_is64;
> +extern u32 image_offset;
>
> __pure efi_system_table_t *efi_system_table(void)
> {
> @@ -364,6 +365,7 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
> struct boot_params *boot_params;
> struct setup_header *hdr;
> efi_loaded_image_t *image;
> + void *image_base;
> efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
> int options_size = 0;
> efi_status_t status;
> @@ -384,7 +386,10 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
> efi_exit(handle, status);
> }
>
> - hdr = &((struct boot_params *)efi_table_attr(image, image_base))->hdr;
> + image_base = efi_table_attr(image, image_base);
> + image_offset = (void *)startup_32 - image_base;
startup_32 == 0, so maybe something like
leaq startup_32(%rip) - image_base
should be used ?
> +
> + hdr = &((struct boot_params *)image_base)->hdr;
> above4g = hdr->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G;
>
> status = efi_allocate_pages(0x4000, (unsigned long *)&boot_params,
> @@ -399,7 +404,7 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
> hdr = &boot_params->hdr;
>
> /* Copy the second sector to boot_params */
> - memcpy(&hdr->jump, efi_table_attr(image, image_base) + 512, 512);
> + memcpy(&hdr->jump, image_base + 512, 512);
>
> /*
> * Fill out some of the header fields ourselves because the
> @@ -726,7 +731,7 @@ unsigned long efi_main(efi_handle_t handle,
> * If the kernel isn't already loaded at the preferred load
> * address, relocate it.
> */
> - if (bzimage_addr != hdr->pref_address) {
> + if (bzimage_addr - image_offset != hdr->pref_address) {
> status = efi_relocate_kernel(&bzimage_addr,
> hdr->init_size, hdr->init_size,
> hdr->pref_address,
> @@ -736,6 +741,7 @@ unsigned long efi_main(efi_handle_t handle,
> efi_printk("efi_relocate_kernel() failed!\n");
> goto fail;
> }
> + image_offset = 0;
> }
>
> /*
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next prev parent reply other threads:[~2020-03-03 6:28 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-01 23:05 [PATCH 0/5] Minimize the need to move the kernel in the EFI stub Arvind Sankar
2020-03-01 23:05 ` [PATCH 1/5] x86/boot/compressed/32: Save the output address instead of recalculating it Arvind Sankar
2020-03-03 19:10 ` Ard Biesheuvel
2020-03-01 23:05 ` [PATCH 2/5] efi/x86: Decompress at start of PE image load address Arvind Sankar
2020-03-03 6:28 ` Mika Penttilä [this message]
2020-03-03 13:45 ` Arvind Sankar
2020-03-03 19:08 ` Ard Biesheuvel
2020-03-01 23:05 ` [PATCH 3/5] efi/x86: Add kernel preferred address to PE header Arvind Sankar
2020-03-03 19:11 ` Ard Biesheuvel
2020-03-01 23:05 ` [PATCH 4/5] efi/x86: Remove extra headroom for setup block Arvind Sankar
2020-03-02 4:21 ` Mika Penttilä
2020-03-03 4:14 ` Arvind Sankar
2020-03-01 23:05 ` [PATCH 5/5] efi/x86: Don't relocate the kernel unless necessary Arvind Sankar
2020-03-03 19:15 ` Ard Biesheuvel
2020-03-03 22:12 ` [PATCH v2 0/5] Minimize the need to move the kernel in the EFI stub Arvind Sankar
2020-03-03 22:12 ` [PATCH v2 1/5] x86/boot/compressed/32: Save the output address instead of recalculating it Arvind Sankar
2020-03-03 22:12 ` [PATCH v2 2/5] efi/x86: Decompress at start of PE image load address Arvind Sankar
2020-03-03 22:12 ` [PATCH v2 3/5] efi/x86: Add kernel preferred address to PE header Arvind Sankar
2020-03-03 22:12 ` [PATCH v2 4/5] efi/x86: Remove extra headroom for setup block Arvind Sankar
2020-05-11 17:01 ` Mike Lothian
2020-05-11 18:36 ` Arvind Sankar
2020-05-11 21:13 ` Ard Biesheuvel
2020-05-11 22:53 ` Arvind Sankar
2020-05-11 22:58 ` [PATCH] x86/boot: Mark global variables as static Arvind Sankar
2020-05-11 23:12 ` Mike Lothian
2020-05-12 11:05 ` Ard Biesheuvel
2020-03-03 22:12 ` [PATCH v2 5/5] efi/x86: Don't relocate the kernel unless necessary Arvind Sankar
2020-03-03 23:08 ` Ard Biesheuvel
2020-03-03 23:34 ` Arvind Sankar
2020-03-04 7:30 ` Ard Biesheuvel
2020-03-03 22:26 ` [PATCH v2 0/5] Minimize the need to move the kernel in the EFI stub Ard Biesheuvel
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