Entry point for Rust pvmfw.
Bug: 223166344
Test: Ran unprotected VM under crosvm.
Change-Id: I89b1c01f9b1ae3bbbe477044f11ed8b87287535a
diff --git a/pvmfw/Android.bp b/pvmfw/Android.bp
index a5e4920..d94334c 100644
--- a/pvmfw/Android.bp
+++ b/pvmfw/Android.bp
@@ -16,3 +16,27 @@
},
apex_available: ["com.android.virt"],
}
+
+cc_binary {
+ name: "pvmfw",
+ srcs: [
+ "entry.S",
+ ],
+ static_libs: [
+ "libpvmfw",
+ ],
+ static_executable: true,
+ no_libcrt: true,
+ nocrt: true,
+ system_shared_libs: [],
+ ldflags: [
+ "-Tpackages/modules/Virtualization/pvmfw/image.ld",
+ ],
+ enabled: false,
+ target: {
+ android_arm64: {
+ enabled: true,
+ },
+ },
+ apex_available: ["com.android.virt"],
+}
diff --git a/pvmfw/entry.S b/pvmfw/entry.S
new file mode 100644
index 0000000..25631cb
--- /dev/null
+++ b/pvmfw/entry.S
@@ -0,0 +1,54 @@
+/*
+ * 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.
+ */
+
+.macro adr_l, reg:req, sym:req
+ adrp \reg, \sym
+ add \reg, \reg, :lo12:\sym
+.endm
+
+/**
+ * This is a generic entry point for an image. It carries out the operations
+ * required to prepare the loaded image to be run. Specifically, it zeroes the
+ * bss section using registers x25 and above, prepares the stack, enables
+ * floating point, and sets up the exception vector.
+ */
+.section .init.entry, "ax"
+.global entry
+entry:
+ /* Disable trapping floating point access in EL1. */
+ mrs x30, cpacr_el1
+ orr x30, x30, #(0x3 << 20)
+ msr cpacr_el1, x30
+ isb
+
+ /* Zero out the bss section. */
+ adr_l x29, bss_begin
+ adr_l x30, bss_end
+0: cmp x29, x30
+ b.hs 1f
+ stp xzr, xzr, [x29], #16
+ b 0b
+
+1: /* Prepare the stack. */
+ adr x30, boot_stack_end
+ mov sp, x30
+
+ /* Call into Rust code. */
+ bl main
+
+ /* Loop forever waiting for interrupts. */
+2: wfi
+ b 2b
diff --git a/pvmfw/image.ld b/pvmfw/image.ld
new file mode 100644
index 0000000..e08fbe2
--- /dev/null
+++ b/pvmfw/image.ld
@@ -0,0 +1,117 @@
+/*
+ * 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.
+ */
+
+MEMORY
+{
+ dtb_region : ORIGIN = 0x80000000, LENGTH = 2M
+ image : ORIGIN = 0x80200000, LENGTH = 2M
+}
+
+/*
+ * 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 = .;
+ } >image
+ /* 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 = .;
+ } >image
+
+ .stack (NOLOAD) : ALIGN(4096) {
+ boot_stack_begin = .;
+ . += 40 * 4096;
+ . = ALIGN(4096);
+ boot_stack_end = .;
+ } >image
+
+ /*
+ * 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)
+ }
+}