boot: Remove unused parameters from pe_kernel_info

Only the compat entry address is used now. This also now only returns
the compat entry address. If the image is native we do not need to try
calling into the entry address again as we would already have done so
from StartImage (and failed).

src/boot/efi/boot.c

@@ -2416,21 +2416,22 @@ static EFI_STATUS image_start(
 
         /* Try calling the kernel compat entry point if one exists. */
         if (err == EFI_UNSUPPORTED && entry->type == LOADER_LINUX) {
-                uint32_t kernel_entry_address;
+                uint32_t compat_address;
 
-                err = pe_kernel_info(loaded_image->ImageBase, &kernel_entry_address, NULL, NULL);
+                err = pe_kernel_info(loaded_image->ImageBase, &compat_address);
                 if (err != EFI_SUCCESS) {
                         if (err != EFI_UNSUPPORTED)
                                 return log_error_status_stall(err, L"Error finding kernel compat entry address: %r", err);
-                } else {
+                } else if (compat_address > 0) {
                         EFI_IMAGE_ENTRY_POINT kernel_entry =
-                                (EFI_IMAGE_ENTRY_POINT) ((uint8_t *) loaded_image->ImageBase + kernel_entry_address);
+                                (EFI_IMAGE_ENTRY_POINT) ((uint8_t *) loaded_image->ImageBase + compat_address);
 
                         err = kernel_entry(image, ST);
                         graphics_mode(false);
                         if (err == EFI_SUCCESS)
                                 return EFI_SUCCESS;
-                }
+                } else
+                        err = EFI_UNSUPPORTED;
         }
 
         return log_error_status_stall(err, L"Failed to execute %s (%s): %r", entry->title_show, entry->loader, err);

src/boot/efi/linux.c

@@ -59,7 +59,7 @@ EFI_STATUS linux_exec(
                 const void *linux_buffer, UINTN linux_length,
                 const void *initrd_buffer, UINTN initrd_length) {
 
-        uint32_t kernel_alignment, kernel_size_of_image, kernel_entry_address = 0;
+        uint32_t compat_address;
         EFI_STATUS err;
 
         assert(parent);
@@ -67,8 +67,7 @@ EFI_STATUS linux_exec(
         assert(linux_buffer && linux_length > 0);
         assert(initrd_buffer || initrd_length == 0);
 
-        /* get the necessary fields from the PE header */
-        err = pe_kernel_info(linux_buffer, &kernel_entry_address, &kernel_size_of_image, &kernel_alignment);
+        err = pe_kernel_info(linux_buffer, &compat_address);
 #if defined(__i386__) || defined(__x86_64__)
         if (err == EFI_UNSUPPORTED)
                 /* Kernel is too old to support LINUX_INITRD_MEDIA_GUID, try the deprecated EFI handover
@@ -108,9 +107,9 @@ EFI_STATUS linux_exec(
         err = BS->StartImage(kernel_image, NULL, NULL);
 
         /* Try calling the kernel compat entry point if one exists. */
-        if (err == EFI_UNSUPPORTED && kernel_entry_address > 0) {
+        if (err == EFI_UNSUPPORTED && compat_address > 0) {
                 EFI_IMAGE_ENTRY_POINT compat_entry =
-                                (EFI_IMAGE_ENTRY_POINT) ((uint8_t *) loaded_image->ImageBase + kernel_entry_address);
+                                (EFI_IMAGE_ENTRY_POINT) ((uint8_t *) loaded_image->ImageBase + compat_address);
                 err = compat_entry(kernel_image, ST);
         }
 

src/boot/efi/pe.c

@@ -215,23 +215,15 @@ static uint32_t get_compatibility_entry_address(const DosFileHeader *dos, const
         return 0;
 }
 
-EFI_STATUS pe_kernel_info(
-                const void *base,
-                uint32_t *ret_entry_point_address,
-                uint32_t *ret_size_of_image,
-                uint32_t *ret_section_alignment) {
-
-        const DosFileHeader *dos;
-        const PeFileHeader *pe;
-
+EFI_STATUS pe_kernel_info(const void *base, uint32_t *ret_compat_address) {
         assert(base);
-        assert(ret_entry_point_address);
+        assert(ret_compat_address);
 
-        dos = (const DosFileHeader *) base;
+        const DosFileHeader *dos = (const DosFileHeader *) base;
         if (!verify_dos(dos))
                 return EFI_LOAD_ERROR;
 
-        pe = (const PeFileHeader *) ((const uint8_t *) base + dos->ExeHeader);
+        const PeFileHeader *pe = (const PeFileHeader *) ((const uint8_t *) base + dos->ExeHeader);
         if (!verify_pe(pe, /* allow_compatibility= */ true))
                 return EFI_LOAD_ERROR;
 
@@ -239,21 +231,17 @@ EFI_STATUS pe_kernel_info(
         if (pe->OptionalHeader.MajorImageVersion < 1)
                 return EFI_UNSUPPORTED;
 
-        uint32_t entry_address = pe->OptionalHeader.AddressOfEntryPoint;
-
-        /* Look for a compat entry point. */
-        if (pe->FileHeader.Machine != TARGET_MACHINE_TYPE) {
-                entry_address = get_compatibility_entry_address(dos, pe);
-                if (entry_address == 0)
-                        /* Image type not supported and no compat entry found. */
-                        return EFI_UNSUPPORTED;
+        if (pe->FileHeader.Machine == TARGET_MACHINE_TYPE) {
+                *ret_compat_address = 0;
+                return EFI_SUCCESS;
         }
 
-        *ret_entry_point_address = entry_address;
-        if (ret_size_of_image)
-                *ret_size_of_image = pe->OptionalHeader.SizeOfImage;
-        if (ret_section_alignment)
-                *ret_section_alignment = pe->OptionalHeader.SectionAlignment;
+        uint32_t compat_address = get_compatibility_entry_address(dos, pe);
+        if (compat_address == 0)
+                /* Image type not supported and no compat entry found. */
+                return EFI_UNSUPPORTED;
+
+        *ret_compat_address = compat_address;
         return EFI_SUCCESS;
 }
 

src/boot/efi/pe.h

@@ -17,8 +17,4 @@ EFI_STATUS pe_file_locate_sections(
                 UINTN *offsets,
                 UINTN *sizes);
 
-EFI_STATUS pe_kernel_info(
-                const void *base,
-                uint32_t *ret_entry_point_address,
-                uint32_t *ret_size_of_image,
-                uint32_t *ret_section_alignment);
+EFI_STATUS pe_kernel_info(const void *base, uint32_t *ret_compat_address);