Changeset 99589a9 in mainline for boot/arch/arm64/src/asm.S

Timestamp:

2021-08-22T16:59:16Z (3 years ago)

Author:

Martin Decky <martin@…>

Branches:

master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

95b7d4df

Parents:

bc52b5b

Message:

Improve compatibility with 3rd-party boot loaders (e.g. U-Boot)

File:

• boot/arch/arm64/src/asm.S (modified) (4 diffs)

boot/arch/arm64/src/asm.S

@@ -33 +33 @@
 .section BOOTSTRAP
 
+#define DIRECTORY_ENTRIES 16
+
 /* MS-DOS stub */
 msdos_stub:
@@ -51 +53 @@
         .long 0                         /* Number of symbols */
         .short sec_table - opt_header   /* Size of optional header */
-        /* Characteristics = IMAGE_FILE_EXECUTABLE_IMAGE |
-         *   IMAGE_FILE_LARGE_ADDRESS_AWARE */
+        /*
+         * Characteristics = IMAGE_FILE_EXECUTABLE_IMAGE |
+         *   IMAGE_FILE_LARGE_ADDRESS_AWARE
+         */
         .short 0x22
 
@@ -87 +91 @@
         .quad 0                         /* Size of heap commit */
         .long 0                         /* Loader flags */
-        .long 0                         /* Number of RVA and sizes */
+        .long DIRECTORY_ENTRIES         /* Number of RVA and sizes */
+        .space DIRECTORY_ENTRIES * 8    /* Directory entries */
 
 sec_table:
-        .ascii ".text\x0\x0\x0"         /* Name */
+        .ascii ".text\x0\x0\x0"         /* Name */
         .long payload_end - start       /* Virtual size */
         .long start - msdos_stub        /* Virtual address */
@@ -99 +104 @@
         .short 0                        /* Number of relocations */
         .short 0                        /* Number of line numbers */
-        /* Characteristics = IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE |
-         *   IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE */
+        /*
+         * Characteristics = IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE |
+         *   IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE
+         */
         .long 0xe0000020
 
+/** Boot loader entry point
+ *
+ * @param x0 UEFI image handle.
+ * @param x1 Pointer to the UEFI system table.
+ *
+ */
 SYMBOL(start)
         .hidden start
 
         /*
-         * Parameters:
-         * x0 is the image handle.
-         * x1 is a pointer to the UEFI system table.
-         */
-
-        /*
-         * Stay on the UEFI stack. Its size is at least 128 kB, plenty for this
+         * Stay on the UEFI stack. Its size is at least 128 KiB, plenty for this
          * boot loader.
          */