Split out common part of linker script.
Bug: 223166344
Test: atest vmbase_example.integration_test
Change-Id: Idaf10e631ba33fcc7026c4e2f603778186215667
diff --git a/vmbase/sections.ld b/vmbase/sections.ld
new file mode 100644
index 0000000..88033e3
--- /dev/null
+++ b/vmbase/sections.ld
@@ -0,0 +1,113 @@
+/*
+ * Copyright 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * Code will start running at this symbol which is placed at the start of the
+ * image.
+ */
+ENTRY(entry)
+
+/*
+ * The following would be useful to check that .init code is not called back
+ * into once it has completed but it isn't supported by ld.lld.
+ *
+ * NOCROSSREFS_TO(.init .text)
+ */
+
+SECTIONS
+{
+ .dtb (NOLOAD) : {
+ dtb_begin = .;
+ . += LENGTH(dtb_region);
+ dtb_end = .;
+ } >dtb_region
+
+ /*
+ * Collect together the code. This is page aligned so it can be mapped
+ * as executable-only.
+ */
+ .init : ALIGN(4096) {
+ text_begin = .;
+ *(.init.entry)
+ *(.init.*)
+ } >image
+ .text : {
+ *(.text.*)
+ } >image
+ text_end = .;
+
+ /*
+ * Collect together read-only data. This is page aligned so it can be
+ * mapped as read-only and non-executable.
+ */
+ .rodata : ALIGN(4096) {
+ rodata_begin = .;
+ *(.rodata.*)
+ } >image
+ .got : {
+ *(.got)
+ } >image
+ rodata_end = .;
+
+ /*
+ * Collect together the read-write data including .bss at the end which
+ * will be zero'd by the entry code. This is page aligned so it can be
+ * mapped as non-executable.
+ */
+ .data : ALIGN(4096) {
+ data_begin = .;
+ *(.data.*)
+ /*
+ * The entry point code assumes that .data is a multiple of 32
+ * bytes long.
+ */
+ . = ALIGN(32);
+ data_end = .;
+ } >writable_data AT>image
+ data_lma = LOADADDR(.data);
+
+ /* Everything beyond this point will not be included in the binary. */
+ bin_end = .;
+
+ /* The entry point code assumes that .bss is 16-byte aligned. */
+ .bss : ALIGN(16) {
+ bss_begin = .;
+ *(.bss.*)
+ *(COMMON)
+ . = ALIGN(16);
+ bss_end = .;
+ } >writable_data
+
+ .stack (NOLOAD) : ALIGN(4096) {
+ boot_stack_begin = .;
+ . += 40 * 4096;
+ . = ALIGN(4096);
+ boot_stack_end = .;
+ } >writable_data
+
+ /*
+ * Remove unused sections from the image.
+ */
+ /DISCARD/ : {
+ /* The image loads itself so doesn't need these sections. */
+ *(.gnu.hash)
+ *(.hash)
+ *(.interp)
+ *(.eh_frame_hdr)
+ *(.eh_frame)
+ *(.note.gnu.build-id)
+ }
+}