[PATCH 01/10] Add EFI handover support to bootm
Heinrich Schuchardt
xypron.glpk at gmx.de
Sun Nov 24 15:43:12 CET 2024
On 11/23/24 20:55, Matthew Garrett wrote:
> From: Matthew Garrett <mgarrett at aurora.tech>
>
> We want to jump into the EFI stub in the kernel so it can perform
> appropriate init and call ExitBootServices. Add support for doing that,
> including ensuring that we copy the kernel to somewhere that's not
> currently being used by the firmware.
>
> Signed-off-by: Matthew Garrett <mgarrett at aurora.tech>
>
> ---
>
> arch/x86/lib/bootm.c | 49 ++++++++++++++++++++++++++++++--------------
> boot/bootm.c | 5 +++++
> include/bootm.h | 6 ++++++
> include/efi.h | 1 +
> lib/efi/efi.c | 1 +
> lib/efi/efi_app.c | 36 ++++++++++++++++++++++++++++++++
> 6 files changed, 83 insertions(+), 15 deletions(-)
>
> diff --git a/arch/x86/lib/bootm.c b/arch/x86/lib/bootm.c
> index 55f581836df..c4446b1f9c6 100644
> --- a/arch/x86/lib/bootm.c
> +++ b/arch/x86/lib/bootm.c
> @@ -150,6 +150,38 @@ error:
> return 1;
> }
>
> +typedef void(*handover_func)(void *, struct efi_system_table *sys_table, struct
> +boot_params *params);
> +
> +int efi_boot(ulong setup_base, ulong entry, bool image_64bit)
> +{
> + struct boot_params *params = (struct boot_params *)setup_base;
> + struct setup_header *hdr = ¶ms->hdr;
> + struct efi_priv *priv = efi_get_priv();
> + handover_func hf;
> + int offset = 0;
> +
> + if (IS_ENABLED(CONFIG_EFI_APP_64BIT)) {
> + if (!image_64bit) {
> + printf("## Can only boot 64-bit kernels\n");
> + return 1;
> + }
> + offset = 512;
> + } else if (image_64bit) {
> + printf("# Can only boot 32-bit kernels\n");
> + return 1;
> + }
> +
> + hdr->code32_start = (int)entry;
> + hdr->type_of_loader = 0x80; /* U-Boot, from Linux Documentation/x86/boot.rst */
> +
> + hf = (handover_func)(entry + hdr->handover_offset + offset);
> + asm volatile ("cli");
> + priv->loaded_image->image_base = (char *)entry;
> + hf(priv->parent_image, priv->sys_table, params);
> + return -EFAULT;
> +}
> +
> int boot_linux_kernel(ulong setup_base, ulong entry, bool image_64bit)
> {
> bootm_announce_and_cleanup();
> @@ -158,21 +190,8 @@ int boot_linux_kernel(ulong setup_base, ulong entry, bool image_64bit)
> timestamp_add_now(TS_U_BOOT_START_KERNEL);
> #endif
>
> - /*
> - * Exit EFI boot services just before jumping, after all console
> - * output, since the console won't be available afterwards.
> - */
> - if (IS_ENABLED(CONFIG_EFI_APP)) {
> - int ret;
> -
> - ret = efi_store_memory_map(efi_get_priv());
> - if (ret)
> - return ret;
> - printf("Exiting EFI boot services\n");
> - ret = efi_call_exit_boot_services();
> - if (ret)
> - return ret;
> - }
> + if (IS_ENABLED(CONFIG_EFI_APP))
> + return efi_boot(setup_base, entry, image_64bit)
>
> if (image_64bit) {
> if (!cpu_has_64bit()) {
> diff --git a/boot/bootm.c b/boot/bootm.c
> index 16a43d519a8..d5caa4cdb31 100644
> --- a/boot/bootm.c
> +++ b/boot/bootm.c
> @@ -49,6 +49,10 @@ __weak void board_quiesce_devices(void)
> {
> }
>
> +__weak void board_fixup_os(image_info_t *os)
> +{
> +}
> +
> #if CONFIG_IS_ENABLED(LEGACY_IMAGE_FORMAT)
> /**
> * image_get_kernel - verify legacy format kernel image
> @@ -999,6 +1003,7 @@ int bootm_run_states(struct bootm_info *bmi, int states)
> /* Load the OS */
> if (!ret && (states & BOOTM_STATE_LOADOS)) {
> iflag = bootm_disable_interrupts();
> + board_fixup_os(&images->os);
> ret = bootm_load_os(images, 0);
> if (ret && ret != BOOTM_ERR_OVERLAP)
> goto err;
> diff --git a/include/bootm.h b/include/bootm.h
> index 61160705215..b0d10123b53 100644
> --- a/include/bootm.h
> +++ b/include/bootm.h
> @@ -217,6 +217,12 @@ void arch_preboot_os(void);
> */
> void board_quiesce_devices(void);
>
> +/*
> + * boards should define this if they need to fix up the kernel before boot
> + * (eg, by modifying the desired load address).
> + */
> +void board_fixup_os(image_info_t *os);
> +
> /**
> * switch_to_non_secure_mode() - switch to non-secure mode
> */
> diff --git a/include/efi.h b/include/efi.h
> index c559fda3004..1d06230439f 100644
> --- a/include/efi.h
> +++ b/include/efi.h
> @@ -459,6 +459,7 @@ static inline struct efi_mem_desc *efi_get_next_mem_desc(
> */
> struct efi_priv {
> efi_handle_t parent_image;
> + struct efi_loaded_image *loaded_image;
> struct efi_system_table *sys_table;
> struct efi_boot_services *boot;
> struct efi_runtime_services *run;
> diff --git a/lib/efi/efi.c b/lib/efi/efi.c
> index bcb34d67465..bb1d9e24f84 100644
> --- a/lib/efi/efi.c
> +++ b/lib/efi/efi.c
> @@ -113,6 +113,7 @@ int efi_init(struct efi_priv *priv, const char *banner, efi_handle_t image,
> efi_puts(priv, "Failed to get loaded image protocol\n");
> return ret;
> }
> + priv->loaded_image = loaded_image;
> priv->image_data_type = loaded_image->image_data_type;
>
> return 0;
> diff --git a/lib/efi/efi_app.c b/lib/efi/efi_app.c
> index 9b94a93ee4f..7c3ef9a7926 100644
> --- a/lib/efi/efi_app.c
> +++ b/lib/efi/efi_app.c
> @@ -14,6 +14,7 @@
> #include <efi.h>
> #include <efi_api.h>
> #include <errno.h>
> +#include <image.h>
> #include <init.h>
> #include <malloc.h>
> #include <sysreset.h>
> @@ -218,6 +219,41 @@ static int efi_sysreset_request(struct udevice *dev, enum sysreset_t type)
> return -EINPROGRESS;
> }
>
> +/*
> + * Attempt to relocate the kernel to somewhere the firmware isn't using
> + */
> +#define PAGE_SIZE_BITS 12
> +void board_fixup_os(image_info_t *os)
> +{
> + int pages;
> + ulong load_addr;
> + u64 addr;
> + efi_status_t status;
> + struct efi_priv *priv = efi_get_priv();
> + struct efi_boot_services *boot = priv->boot;
> +
> + pages = (os->image_len + ((1 << PAGE_SIZE_BITS) - 1)) >> PAGE_SIZE_BITS;
> +
> + addr = os->load;
> +
> + /* Try to allocate at the preferred address */
> + status = boot->allocate_pages(EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
> + pages, &addr);
> + if (status == EFI_SUCCESS)
> + return;
> +
> + /* That failed, so try allocating anywhere there's enough room */
> + status = boot->allocate_pages(EFI_ALLOCATE_ANY_PAGES, EFI_LOADER_DATA, pages, &addr);
> + if (status == EFI_SUCCESS) {
> + /* Make sure bootm knows where we loaded the image */
> + os->load = addr;
> + return;
> + }
Why don't you simply call LoadImage()?
Best regards
Heinrich
> +
> + printf("Failed to alloc %lx bytes at %lx: %lx\n", os->image_len, load_addr,
> + status);
> +}
> +
> static const struct udevice_id efi_sysreset_ids[] = {
> { .compatible = "efi,reset" },
> { }
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