tests: Add migration test for aarch64

The x86 boot block header currently is generated with a shell script. To better support other CPUs (e.g. aarch64), we convert the script into Makefile. This allows us to 1) support cross-compilation easily, and 2) avoid creating a script file for every architecture.

Signed-off-by Wei Huang <[email protected]>

---
 tests/migration/Makefile                 | 38 ++++++++++++++++++++++++++++++++
 tests/migration/rebuild-x86-bootblock.sh | 33 ---------------------------
 tests/migration/x86-a-b-bootblock.h      |  2 +-
 tests/migration/x86-a-b-bootblock.s      |  5 ++---
 4 files changed, 41 insertions(+), 37 deletions(-)
 create mode 100644 tests/migration/Makefile
 delete mode 100755 tests/migration/rebuild-x86-bootblock.sh

tests/migration/Makefile new file +7 -0

new file mode 100644
index 0000000000..1c07dd7be9
@@ -0,0 +1,38 @@
+#
+# Copyright (c) 2016-2018 Red Hat, Inc. and/or its affiliates
+#
+# Authors:
+#   Dave Gilbert <[email protected]>
+#
+# This work is licensed under the terms of the GNU GPL, version 2 or later.

tests/migration/Makefile new file +21 -0

+
+export __note
+override define __note
+/* This file is automatically generated from
+ * tests/migration/$<, edit that and then run
+ * "make $@" inside tests/migration to update,
+ * and then remember to send both in your patch submission.
+ */
+endef
+
+all: x86-a-b-bootblock.h
+
+x86-a-b-bootblock.h: x86-a-b-bootblock.s
+	$(x86_64_cross_prefix)as --32 -march=i486 $< -o x86.o
+	$(x86_64_cross_prefix)objcopy -O binary x86.o x86.boot
+	dd if=x86.boot of=x86.bootsect bs=256 count=2 skip=124
+	echo "$$__note" > $@
+	xxd -i x86.bootsect | sed -e 's/.*int.*//' >> $@
+
+clean:
+	rm -f *.bootsect *.boot *.o

tests/migration/rebuild-x86-bootblock.sh deleted +0 -33

deleted file mode 100755
index 86cec5d284..0000000000
@@ -1,33 +0,0 @@
-#!/bin/sh
-# Copyright (c) 2016-2018 Red Hat, Inc. and/or its affiliates
-# This work is licensed under the terms of the GNU GPL, version 2 or later.
-# See the COPYING file in the top-level directory.
-#
-# Author: [email protected]
-
-ASMFILE=$PWD/tests/migration/x86-a-b-bootblock.s
-HEADER=$PWD/tests/migration/x86-a-b-bootblock.h
-
-if [ ! -e "$ASMFILE" ]
-then
-  echo "Couldn't find $ASMFILE" >&2
-  exit 1
-fi
-
-ASM_WORK_DIR=$(mktemp -d --tmpdir X86BB.XXXXXX)
-cd "$ASM_WORK_DIR" &&
-as --32 -march=i486 "$ASMFILE" -o x86.o &&
-objcopy -O binary x86.o x86.boot &&
-dd if=x86.boot of=x86.bootsect bs=256 count=2 skip=124 &&
-xxd -i x86.bootsect |
-sed -e 's/.*int.*//' > x86.hex &&
-cat - x86.hex <<HERE > "$HEADER"
-/* This file is automatically generated from
- * tests/migration/x86-a-b-bootblock.s, edit that and then run
- * tests/migration/rebuild-x86-bootblock.sh to update,
- * and then remember to send both in your patch submission.
- */
-HERE
-
-rm x86.hex x86.bootsect x86.boot x86.o
-cd .. && rmdir "$ASM_WORK_DIR"

tests/migration/x86-a-b-bootblock.h +1 -1

index 78a151fe2a..9e8e2e028b 100644
@@ -1,6 +1,6 @@
 /* This file is automatically generated from
  * tests/migration/x86-a-b-bootblock.s, edit that and then run
- * tests/migration/rebuild-x86-bootblock.sh to update,
+ * "make x86-a-b-bootblock.h" inside tests/migration to update,
  * and then remember to send both in your patch submission.
  */
 unsigned char x86_bootsect[] = {

tests/migration/x86-a-b-bootblock.s +2 -3

index b1642641a7..98dbfab084 100644
@@ -3,9 +3,8 @@
 #  range.
 #  Outputs an initial 'A' on serial followed by repeated 'B's
 #
-# run   tests/migration/rebuild-x86-bootblock.sh
-#   to regenerate the hex, and remember to include both the .h and .s
-#   in any patches.
+#  In tests/migration dir, run 'make x86-a-b-bootblock.h' to regenerate
+#  the hex, and remember to include both the .h and .s in any patches.
 #
 # Copyright (c) 2016 Red Hat, Inc. and/or its affiliates
 # This work is licensed under the terms of the GNU GPL, version 2 or later.

Signature · 1 line

2.14.3

This patch moves the settings related migration-test from the migration-test.c file to a seperate header file. It also renames the x86-a-b-bootblock.s file extension from .s to .S, allowing gcc pre-processor to include the C-style header file correctly.

Signed-off-by Wei Huang <[email protected]>

---
 tests/migration-test.c                                |  9 +++++----
 tests/migration/Makefile                              |  4 ++--
 tests/migration/migration-test.h                      | 19 +++++++++++++++++++
 .../{x86-a-b-bootblock.s => x86-a-b-bootblock.S}      |  7 ++++---
 tests/migration/x86-a-b-bootblock.h                   |  2 +-
 5 files changed, 31 insertions(+), 10 deletions(-)
 create mode 100644 tests/migration/migration-test.h
 rename tests/migration/{x86-a-b-bootblock.s => x86-a-b-bootblock.S} (94%)

tests/migration-test.c +3 -3

index 74f9361bdd..e2e06ed337 100644
@@ -21,10 +21,10 @@
 #include "sysemu/sysemu.h"
 #include "hw/nvram/chrp_nvram.h"
 
-#define MIN_NVRAM_SIZE 8192 /* from spapr_nvram.c */
+#include "migration/migration-test.h"
 
-const unsigned start_address = 1024 * 1024;
-const unsigned end_address = 100 * 1024 * 1024;
+const unsigned start_address = TEST_MEM_START;
+const unsigned end_address = TEST_MEM_END;
 bool got_stop;
 
 #if defined(__linux__)

tests/migration/Makefile +2 -2

index 1c07dd7be9..b768d0729d 100644
@@ -27,8 +27,8 @@ endef
 
 all: x86-a-b-bootblock.h
 
-x86-a-b-bootblock.h: x86-a-b-bootblock.s
-	$(x86_64_cross_prefix)as --32 -march=i486 $< -o x86.o
+x86-a-b-bootblock.h: x86-a-b-bootblock.S
+	$(x86_64_cross_prefix)gcc -m32 -march=i486 -c $< -o x86.o
 	$(x86_64_cross_prefix)objcopy -O binary x86.o x86.boot
 	dd if=x86.boot of=x86.bootsect bs=256 count=2 skip=124
 	echo "$$__note" > $@

tests/migration/migration-test.h new file +9 -0

new file mode 100644
index 0000000000..a618fe069e
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2018 Red Hat, Inc. and/or its affiliates
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+#ifndef _TEST_MIGRATION_H_
+#define _TEST_MIGRATION_H_
+

tests/migration/x86-a-b-bootblock.S renamed from tests/migration/x86-a-b-bootblock.s +4 -3

similarity index 94%
rename from tests/migration/x86-a-b-bootblock.s
rename to tests/migration/x86-a-b-bootblock.S
index 98dbfab084..08b51f9e7f 100644
@@ -12,6 +12,7 @@
 #
 # Author: [email protected]
 
+#include "migration-test.h"
 
 .code16
 .org 0x7c00

@@ -45,11 +46,11 @@ start:             # at 0x7c00 ?
         mov $0, %bl
 mainloop:
         # Start from 1MB
-        mov $(1024*1024),%eax
+        mov $TEST_MEM_START,%eax
 innerloop:
         incb (%eax)
-        add $4096,%eax
-        cmp $(100*1024*1024),%eax
+        add $TEST_MEM_PAGE_SIZE,%eax
+        cmp $TEST_MEM_END,%eax
         jl innerloop
 
         inc %bl

tests/migration/x86-a-b-bootblock.h +1 -1

index 9e8e2e028b..44e4b99506 100644
@@ -1,5 +1,5 @@
 /* This file is automatically generated from
- * tests/migration/x86-a-b-bootblock.s, edit that and then run
+ * tests/migration/x86-a-b-bootblock.S, edit that and then run
  * "make x86-a-b-bootblock.h" inside tests/migration to update,
  * and then remember to send both in your patch submission.
  */

Signature · 1 line

2.14.3

This patch adds migration test support for aarch64. The test code, which implements the same functionality as x86, is booted as a kernel in qemu. Here are the design choices we make for aarch64:

* We choose this -kernel approach because aarch64 QEMU doesn't provide a built-in fw like x86 does. So instead of relying on a boot loader, we use -kernel approach for aarch64.
* The serial output is sent to PL011 directly.
* The physical memory base for mach-virt machine is 0x40000000. We change the start_address and end_address for aarch64.

In addition to providing the binary, this patch also includes the source code and the build script in tests/migration/. So users can change the source and/or re-compile the binary as they wish.

Signed-off-by Wei Huang <[email protected]>

---
 tests/Makefile.include               |  1 +
 tests/migration-test.c               | 47 +++++++++++++++++++++---
 tests/migration/Makefile             | 12 +++++-
 tests/migration/aarch64-a-b-kernel.S | 71 ++++++++++++++++++++++++++++++++++++
 tests/migration/aarch64-a-b-kernel.h | 19 ++++++++++
 tests/migration/migration-test.h     |  5 +++
 6 files changed, 147 insertions(+), 8 deletions(-)
 create mode 100644 tests/migration/aarch64-a-b-kernel.S
 create mode 100644 tests/migration/aarch64-a-b-kernel.h

tests/Makefile.include +1 -0

index a1bcbffe12..df9f64438f 100644
@@ -372,6 +372,7 @@ check-qtest-arm-y += tests/sdhci-test$(EXESUF)
 check-qtest-aarch64-y = tests/numa-test$(EXESUF)
 check-qtest-aarch64-y += tests/sdhci-test$(EXESUF)
 check-qtest-aarch64-y += tests/boot-serial-test$(EXESUF)
+check-qtest-aarch64-y += tests/migration-test$(EXESUF)
 
 check-qtest-microblazeel-y = $(check-qtest-microblaze-y)
 

tests/migration-test.c +41 -6

index e2e06ed337..a4f6732a59 100644
@@ -11,6 +11,7 @@
  */
 
 #include "qemu/osdep.h"
+#include <sys/utsname.h>
 
 #include "libqtest.h"
 #include "qapi/qmp/qdict.h"

@@ -23,8 +24,8 @@
 
 #include "migration/migration-test.h"
 
-const unsigned start_address = TEST_MEM_START;
-const unsigned end_address = TEST_MEM_END;
+unsigned start_address = TEST_MEM_START;
+unsigned end_address = TEST_MEM_END;
 bool got_stop;
 
 #if defined(__linux__)

@@ -81,12 +82,13 @@ static const char *tmpfs;
  * outputting a 'B' every so often if it's still running.
  */
 #include "tests/migration/x86-a-b-bootblock.h"
+#include "tests/migration/aarch64-a-b-kernel.h"
 
-static void init_bootfile_x86(const char *bootpath)
+static void init_bootfile(const char *bootpath, void *content)
 {
     FILE *bootfile = fopen(bootpath, "wb");
 
-    g_assert_cmpint(fwrite(x86_bootsect, 512, 1, bootfile), ==, 1);
+    g_assert_cmpint(fwrite(content, 512, 1, bootfile), ==, 1);
     fclose(bootfile);
 }
 

@@ -393,7 +395,7 @@ static void test_migrate_start(QTestState **from, QTestState **to,
     got_stop = false;
 
     if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
-        init_bootfile_x86(bootpath);
+        init_bootfile(bootpath, x86_bootsect);
         cmd_src = g_strdup_printf("-machine accel=%s -m 150M"
                                   " -name source,debug-threads=on"
                                   " -serial file:%s/src_serial"

@@ -422,6 +424,39 @@ static void test_migrate_start(QTestState **from, QTestState **to,
                                   " -serial file:%s/dest_serial"
                                   " -incoming %s",
                                   accel, tmpfs, uri);
+    } else if (strcmp(arch, "aarch64") == 0) {
+        const char *cpu;
+        const char *gic_ver;
+        struct utsname utsname;
+
+        /* kvm and tcg need different cpu and gic-version configs */
+        if (access("/dev/kvm", F_OK) == 0 && uname(&utsname) == 0 &&
+            strcmp(utsname.machine, "aarch64") == 0) {
+            accel = "kvm";
+            cpu = "host";
+            gic_ver = "host";
+        } else {
+            accel = "tcg";
+            cpu = "cortex-a57";
+            gic_ver = "2";
+        }
+
+        init_bootfile(bootpath, aarch64_kernel);
+        cmd_src = g_strdup_printf("-machine virt,accel=%s,gic-version=%s "
+                                  "-name vmsource,debug-threads=on -cpu %s "
+                                  "-m 150M -serial file:%s/src_serial "
+                                  "-kernel %s ",
+                                  accel, gic_ver, cpu, tmpfs, bootpath);
+        cmd_dst = g_strdup_printf("-machine virt,accel=%s,gic-version=%s "
+                                  "-name vmdest,debug-threads=on -cpu %s "
+                                  "-m 150M -serial file:%s/dest_serial "
+                                  "-kernel %s "
+                                  "-incoming %s ",
+                                  accel, gic_ver, cpu, tmpfs, bootpath, uri);
+
+        /* aarch64 virt machine physical memory starts at 0x40000000 */
+        start_address = ARM_TEST_MEM_START;
+        end_address = ARM_TEST_MEM_END;
     } else {
         g_assert_not_reached();
     }

@@ -506,7 +541,7 @@ static void test_deprecated(void)
 {
     QTestState *from;
 
-    from = qtest_start("");
+    from = qtest_start("-machine none");
 
     deprecated_set_downtime(from, 0.12345);
     deprecated_set_speed(from, "12345");

tests/migration/Makefile +2 -1

index b768d0729d..b72d41367f 100644
@@ -15,6 +15,7 @@ cross-gcc = $(firstword $(wildcard $(patsubst %ld,%gcc,$(call cross-ld,$(1)))))
 find-cross-prefix = $(subst gcc,,$(notdir $(call cross-gcc,$(1))))
 
 x86_64_cross_prefix := $(call find-cross-prefix,x86_64)
+aarch64_cross_prefix := $(call find-cross-prefix,aarch64)
 
 export __note
 override define __note

@@ -25,7 +26,7 @@ override define __note
  */
 endef
 
-all: x86-a-b-bootblock.h
+all: x86-a-b-bootblock.h aarch64-a-b-kernel.h
 
 x86-a-b-bootblock.h: x86-a-b-bootblock.S
 	$(x86_64_cross_prefix)gcc -m32 -march=i486 -c $< -o x86.o

tests/migration/Makefile +5 -1

+	$(aarch64_cross_prefix)objcopy -O binary aarch64.elf aarch64.kernel
+	echo "$$__note" > $@
+	xxd -i aarch64.kernel | sed -e 's/.*int.*//' >> $@
+
 clean:
-	rm -f *.bootsect *.boot *.o
+	rm -f *.bootsect *.boot *.o *.elf *.kernel

tests/migration/aarch64-a-b-kernel.S new file +13 -0

new file mode 100644
index 0000000000..deadcbbdc6
@@ -0,0 +1,71 @@
+#
+# Copyright (c) 2018 Red Hat, Inc. and/or its affiliates
+#
+# Author:
+#   Wei Huang <[email protected]>
+#
+# This work is licensed under the terms of the GNU GPL, version 2 or later.
+# See the COPYING file in the top-level directory.
+
+#include "migration-test.h"
+
+.section .text
+

tests/migration/aarch64-a-b-kernel.S new file +19 -0

+        mov     x0, #ARM_TEST_MEM_START
+        mov     x1, #ARM_TEST_MEM_END
+
+        /* output char 'A' to PL011 */
+        mov     w3, 'A'
+        mov     x2, #ARM_MACH_VIRT_UART
+        strb    w3, [x2]
+
+        /* clean up memory */
+        mov     w3, #0
+        mov     x4, x0
+clean:
+        strb    w3, [x4]
+        add     x4, x4, #TEST_MEM_PAGE_SIZE
+        cmp     x4, x1
+        ble     clean
+
+        /* w5 keeps a counter so we can limit the output speed */
+        mov     w5, #0

tests/migration/aarch64-a-b-kernel.S new file +9 -0

+        ldrb    w3, [x4]
+        add     w3, w3, #1
+        and     w3, w3, #0xff
+        strb    w3, [x4]
+
+        add     x4, x4, #TEST_MEM_PAGE_SIZE
+        cmp     x4, x1
+        blt     innerloop
+

tests/migration/aarch64-a-b-kernel.h new file +19 -0

new file mode 100644
index 0000000000..a3dab67aed
@@ -0,0 +1,19 @@
+/* This file is automatically generated from
+ * tests/migration/aarch64-a-b-kernel.S, edit that and then run
+ * "make aarch64-a-b-kernel.h" inside tests/migration to update,
+ * and then remember to send both in your patch submission.
+ */
+unsigned char aarch64_kernel[] = {
+  0x00, 0x10, 0x38, 0xd5, 0x00, 0xf8, 0x7f, 0x92, 0x00, 0x10, 0x18, 0xd5,
+  0xdf, 0x3f, 0x03, 0xd5, 0x00, 0x02, 0xa8, 0xd2, 0x01, 0xc8, 0xa8, 0xd2,
+  0x23, 0x08, 0x80, 0x52, 0x02, 0x20, 0xa1, 0xd2, 0x43, 0x00, 0x00, 0x39,
+  0x03, 0x00, 0x80, 0x52, 0xe4, 0x03, 0x00, 0xaa, 0x83, 0x00, 0x00, 0x39,
+  0x84, 0x04, 0x40, 0x91, 0x9f, 0x00, 0x01, 0xeb, 0xad, 0xff, 0xff, 0x54,
+  0x05, 0x00, 0x80, 0x52, 0xe4, 0x03, 0x00, 0xaa, 0x24, 0x7e, 0x0b, 0xd5,
+  0x83, 0x00, 0x40, 0x39, 0x63, 0x04, 0x00, 0x11, 0x63, 0x1c, 0x00, 0x12,
+  0x83, 0x00, 0x00, 0x39, 0x84, 0x04, 0x40, 0x91, 0x9f, 0x00, 0x01, 0xeb,
+  0x2b, 0xff, 0xff, 0x54, 0xa5, 0x04, 0x00, 0x11, 0xa5, 0x1c, 0x00, 0x12,
+  0xbf, 0x00, 0x00, 0x71, 0x81, 0xfe, 0xff, 0x54, 0x43, 0x08, 0x80, 0x52,
+  0x43, 0x00, 0x00, 0x39, 0xf1, 0xff, 0xff, 0x97
+};
+

tests/migration/migration-test.h +0 -0

index a618fe069e..8c3fef3a0c 100644

tests/migration/migration-test.h +0 -0

 #endif /* _TEST_MIGRATION_H_ */
 

Signature · 1 line

2.14.3

Quoted 161 lines · Wei Huang

This patch adds migration test support for aarch64. The test code, which implements the same functionality as x86, is booted as a kernel in qemu. Here are the design choices we make for aarch64:

* We choose this -kernel approach because aarch64 QEMU doesn't provide a built-in fw like x86 does. So instead of relying on a boot loader, we use -kernel approach for aarch64.
* The serial output is sent to PL011 directly.
* The physical memory base for mach-virt machine is 0x40000000. We change the start_address and end_address for aarch64.

In addition to providing the binary, this patch also includes the source code and the build script in tests/migration/. So users can change the source and/or re-compile the binary as they wish.

Signed-off-by Wei Huang <[email protected]>

---
 tests/Makefile.include               |  1 +
 tests/migration-test.c               | 47 +++++++++++++++++++++---
 tests/migration/Makefile             | 12 +++++-
 tests/migration/aarch64-a-b-kernel.S | 71 ++++++++++++++++++++++++++++++++++++
 tests/migration/aarch64-a-b-kernel.h | 19 ++++++++++
 tests/migration/migration-test.h     |  5 +++
 6 files changed, 147 insertions(+), 8 deletions(-)
 create mode 100644 tests/migration/aarch64-a-b-kernel.S
 create mode 100644 tests/migration/aarch64-a-b-kernel.h

tests/Makefile.include +1 -0

index a1bcbffe12..df9f64438f 100644
@@ -372,6 +372,7 @@ check-qtest-arm-y += tests/sdhci-test$(EXESUF)
 check-qtest-aarch64-y = tests/numa-test$(EXESUF)
 check-qtest-aarch64-y += tests/sdhci-test$(EXESUF)
 check-qtest-aarch64-y += tests/boot-serial-test$(EXESUF)
+check-qtest-aarch64-y += tests/migration-test$(EXESUF)
 
 check-qtest-microblazeel-y = $(check-qtest-microblaze-y)
 

tests/migration-test.c +41 -6

index e2e06ed337..a4f6732a59 100644
@@ -11,6 +11,7 @@
  */
 
 #include "qemu/osdep.h"
+#include <sys/utsname.h>
 
 #include "libqtest.h"
 #include "qapi/qmp/qdict.h"

@@ -23,8 +24,8 @@
 
 #include "migration/migration-test.h"
 
-const unsigned start_address = TEST_MEM_START;
-const unsigned end_address = TEST_MEM_END;
+unsigned start_address = TEST_MEM_START;
+unsigned end_address = TEST_MEM_END;
 bool got_stop;
 
 #if defined(__linux__)

@@ -81,12 +82,13 @@ static const char *tmpfs;
  * outputting a 'B' every so often if it's still running.
  */
 #include "tests/migration/x86-a-b-bootblock.h"
+#include "tests/migration/aarch64-a-b-kernel.h"
 
-static void init_bootfile_x86(const char *bootpath)
+static void init_bootfile(const char *bootpath, void *content)
 {
     FILE *bootfile = fopen(bootpath, "wb");
 
-    g_assert_cmpint(fwrite(x86_bootsect, 512, 1, bootfile), ==, 1);
+    g_assert_cmpint(fwrite(content, 512, 1, bootfile), ==, 1);
     fclose(bootfile);
 }
 

@@ -393,7 +395,7 @@ static void test_migrate_start(QTestState **from, QTestState **to,
     got_stop = false;
 
     if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
-        init_bootfile_x86(bootpath);
+        init_bootfile(bootpath, x86_bootsect);
         cmd_src = g_strdup_printf("-machine accel=%s -m 150M"
                                   " -name source,debug-threads=on"
                                   " -serial file:%s/src_serial"

@@ -422,6 +424,39 @@ static void test_migrate_start(QTestState **from, QTestState **to,
                                   " -serial file:%s/dest_serial"
                                   " -incoming %s",
                                   accel, tmpfs, uri);
+    } else if (strcmp(arch, "aarch64") == 0) {
+        const char *cpu;
+        const char *gic_ver;
+        struct utsname utsname;
+
+        /* kvm and tcg need different cpu and gic-version configs */
+        if (access("/dev/kvm", F_OK) == 0 && uname(&utsname) == 0 &&
+            strcmp(utsname.machine, "aarch64") == 0) {
+            accel = "kvm";
+            cpu = "host";
+            gic_ver = "host";
+        } else {
+            accel = "tcg";
+            cpu = "cortex-a57";
+            gic_ver = "2";
+        }
+
+        init_bootfile(bootpath, aarch64_kernel);
+        cmd_src = g_strdup_printf("-machine virt,accel=%s,gic-version=%s "
+                                  "-name vmsource,debug-threads=on -cpu %s "
+                                  "-m 150M -serial file:%s/src_serial "
+                                  "-kernel %s ",
+                                  accel, gic_ver, cpu, tmpfs, bootpath);
+        cmd_dst = g_strdup_printf("-machine virt,accel=%s,gic-version=%s "
+                                  "-name vmdest,debug-threads=on -cpu %s "
+                                  "-m 150M -serial file:%s/dest_serial "
+                                  "-kernel %s "
+                                  "-incoming %s ",
+                                  accel, gic_ver, cpu, tmpfs, bootpath, uri);
+
+        /* aarch64 virt machine physical memory starts at 0x40000000 */
+        start_address = ARM_TEST_MEM_START;
+        end_address = ARM_TEST_MEM_END;
     } else {
         g_assert_not_reached();
     }

@@ -506,7 +541,7 @@ static void test_deprecated(void)
 {
     QTestState *from;
 
-    from = qtest_start("");
+    from = qtest_start("-machine none");
 
     deprecated_set_downtime(from, 0.12345);
     deprecated_set_speed(from, "12345");

tests/migration/Makefile +2 -1

index b768d0729d..b72d41367f 100644
@@ -15,6 +15,7 @@ cross-gcc = $(firstword $(wildcard $(patsubst %ld,%gcc,$(call cross-ld,$(1)))))
 find-cross-prefix = $(subst gcc,,$(notdir $(call cross-gcc,$(1))))
 
 x86_64_cross_prefix := $(call find-cross-prefix,x86_64)
+aarch64_cross_prefix := $(call find-cross-prefix,aarch64)
 
 export __note
 override define __note

@@ -25,7 +26,7 @@ override define __note
  */
 endef
 
-all: x86-a-b-bootblock.h
+all: x86-a-b-bootblock.h aarch64-a-b-kernel.h
 
 x86-a-b-bootblock.h: x86-a-b-bootblock.S
 	$(x86_64_cross_prefix)gcc -m32 -march=i486 -c $< -o x86.o

@@ -34,5 +35,12 @@ x86-a-b-bootblock.h: x86-a-b-bootblock.S
 	echo "$$__note" > $@
 	xxd -i x86.bootsect | sed -e 's/.*int.*//' >> $@
 

tests/migration/Makefile x86-a-b-bootblock.h: x86-a-b-bootblock.S · line 40

Quoted 3 lines

tests/migration/Makefile +3 -0

+aarch64-a-b-kernel.h: aarch64-a-b-kernel.S
+	$(aarch64_cross_prefix)gcc -o aarch64.elf -nostdlib \
+		-Wl,--build-id=none,-Ttext=40080000 $<

Adding the arm64 Linux kernel offset here is a bit subtle. And, since the TEST_MEM_START is at 1M, that only leaves 512K for test code and data. I think you may want to define this offset somewhere, making it less subtle, and then also factor it in when computing the test mem start.

Quoted 27 lines

tests/migration/Makefile +5 -1

+	$(aarch64_cross_prefix)objcopy -O binary aarch64.elf aarch64.kernel
+	echo "$$__note" > $@
+	xxd -i aarch64.kernel | sed -e 's/.*int.*//' >> $@
+
 clean:
-	rm -f *.bootsect *.boot *.o
+	rm -f *.bootsect *.boot *.o *.elf *.kernel

tests/migration/aarch64-a-b-kernel.S new file +13 -0

new file mode 100644
index 0000000000..deadcbbdc6
@@ -0,0 +1,71 @@
+#
+# Copyright (c) 2018 Red Hat, Inc. and/or its affiliates
+#
+# Author:
+#   Wei Huang <[email protected]>
+#
+# This work is licensed under the terms of the GNU GPL, version 2 or later.
+# See the COPYING file in the top-level directory.
+
+#include "migration-test.h"
+
+.section .text
+

tests/migration/aarch64-a-b-kernel.S line 23

Quoted 10 lines

tests/migration/aarch64-a-b-kernel.S new file +10 -0

+        .globl  _start
+
+_start:
+        /* disable MMU to use phys mem address */
+        mrs     x0, sctlr_el1
+        bic     x0, x0, #(1<<0)
+        msr     sctlr_el1, x0
+        isb
+
+        /* traverse 1M-100M */

s/1M-100M/the test memory region/

There's no reason to create nice defines if we still have to maintain the comments.

Quoted 19 lines

tests/migration/aarch64-a-b-kernel.S new file +19 -0

+        mov     x0, #ARM_TEST_MEM_START
+        mov     x1, #ARM_TEST_MEM_END
+
+        /* output char 'A' to PL011 */
+        mov     w3, 'A'
+        mov     x2, #ARM_MACH_VIRT_UART
+        strb    w3, [x2]
+
+        /* clean up memory */
+        mov     w3, #0
+        mov     x4, x0
+clean:
+        strb    w3, [x4]
+        add     x4, x4, #TEST_MEM_PAGE_SIZE
+        cmp     x4, x1
+        ble     clean
+
+        /* w5 keeps a counter so we can limit the output speed */
+        mov     w5, #0

tests/migration/aarch64-a-b-kernel.S line 52

Quoted 10 lines

tests/migration/aarch64-a-b-kernel.S new file +10 -0

+
+        /* main body */
+mainloop:
+        mov     x4, x0
+
+innerloop:
+        /* clean cache because el2 might still cache guest data under KVM */
+        dc      civac, x4
+
+        /* increment the first byte of each 4KB page by 1 */

s/4KB page/page/

Quoted 9 lines

tests/migration/aarch64-a-b-kernel.S new file +9 -0

+        ldrb    w3, [x4]
+        add     w3, w3, #1
+        and     w3, w3, #0xff
+        strb    w3, [x4]
+
+        add     x4, x4, #TEST_MEM_PAGE_SIZE
+        cmp     x4, x1
+        blt     innerloop
+

tests/migration/aarch64-a-b-kernel.S line 71

Quoted 10 lines

tests/migration/aarch64-a-b-kernel.S new file +10 -0

+        add     w5, w5, #1
+        and     w5, w5, #0xff
+        cmp     w5, #0
+        bne     mainloop
+
+        /* output char 'B' to PL011 */
+        mov     w3, 'B'
+        strb    w3, [x2]
+
+        bl      mainloop

nit: should use just 'b' here, no need to set the link register.

Quoted 30 lines

tests/migration/aarch64-a-b-kernel.h new file +19 -0

new file mode 100644
index 0000000000..a3dab67aed
@@ -0,0 +1,19 @@
+/* This file is automatically generated from
+ * tests/migration/aarch64-a-b-kernel.S, edit that and then run
+ * "make aarch64-a-b-kernel.h" inside tests/migration to update,
+ * and then remember to send both in your patch submission.
+ */
+unsigned char aarch64_kernel[] = {
+  0x00, 0x10, 0x38, 0xd5, 0x00, 0xf8, 0x7f, 0x92, 0x00, 0x10, 0x18, 0xd5,
+  0xdf, 0x3f, 0x03, 0xd5, 0x00, 0x02, 0xa8, 0xd2, 0x01, 0xc8, 0xa8, 0xd2,
+  0x23, 0x08, 0x80, 0x52, 0x02, 0x20, 0xa1, 0xd2, 0x43, 0x00, 0x00, 0x39,
+  0x03, 0x00, 0x80, 0x52, 0xe4, 0x03, 0x00, 0xaa, 0x83, 0x00, 0x00, 0x39,
+  0x84, 0x04, 0x40, 0x91, 0x9f, 0x00, 0x01, 0xeb, 0xad, 0xff, 0xff, 0x54,
+  0x05, 0x00, 0x80, 0x52, 0xe4, 0x03, 0x00, 0xaa, 0x24, 0x7e, 0x0b, 0xd5,
+  0x83, 0x00, 0x40, 0x39, 0x63, 0x04, 0x00, 0x11, 0x63, 0x1c, 0x00, 0x12,
+  0x83, 0x00, 0x00, 0x39, 0x84, 0x04, 0x40, 0x91, 0x9f, 0x00, 0x01, 0xeb,
+  0x2b, 0xff, 0xff, 0x54, 0xa5, 0x04, 0x00, 0x11, 0xa5, 0x1c, 0x00, 0x12,
+  0xbf, 0x00, 0x00, 0x71, 0x81, 0xfe, 0xff, 0x54, 0x43, 0x08, 0x80, 0x52,
+  0x43, 0x00, 0x00, 0x39, 0xf1, 0xff, 0xff, 0x97
+};
+

tests/migration/migration-test.h +0 -0

index a618fe069e..8c3fef3a0c 100644

tests/migration/migration-test.h line 22

Quoted 8 lines

tests/migration/migration-test.h +5 -0

@@ -15,5 +15,10 @@
 /* PPC */
 #define MIN_NVRAM_SIZE 8192 /* from spapr_nvram.c */
 
+/* AArch64 */
+#define ARM_MACH_VIRT_UART  0x09000000
+#define ARM_TEST_MEM_START  (0x40000000 + TEST_MEM_START)
+#define ARM_TEST_MEM_END    (0x40000000 + TEST_MEM_END)
+

As stated above, this should be something like

#define ARM_TEST_MEM_START (0x40000000 + ARM64_KERNEL_OFFSET + TEST_MEM_START)
#define ARM_TEST_MEM_END (0x40000000 + ARM64_KERNEL_OFFSET + TEST_MEM_END)

Otherwise, it's not even obvious that TEST_MEM_START > ARM64_KERNEL_OFFSET

Thanks,
drew

Quoted 6 lines

tests/migration/migration-test.h +0 -0

 #endif /* _TEST_MIGRATION_H_ */
 

Signature · 1 line

2.14.3

Quoted 162 lines · Andrew Jones

Quoted 161 lines · Wei Huang

This patch adds migration test support for aarch64. The test code, which implements the same functionality as x86, is booted as a kernel in qemu. Here are the design choices we make for aarch64:

* We choose this -kernel approach because aarch64 QEMU doesn't provide a built-in fw like x86 does. So instead of relying on a boot loader, we use -kernel approach for aarch64.
* The serial output is sent to PL011 directly.
* The physical memory base for mach-virt machine is 0x40000000. We change the start_address and end_address for aarch64.

In addition to providing the binary, this patch also includes the source code and the build script in tests/migration/. So users can change the source and/or re-compile the binary as they wish.

Signed-off-by Wei Huang <[email protected]>

---
 tests/Makefile.include               |  1 +
 tests/migration-test.c               | 47 +++++++++++++++++++++---
 tests/migration/Makefile             | 12 +++++-
 tests/migration/aarch64-a-b-kernel.S | 71 ++++++++++++++++++++++++++++++++++++
 tests/migration/aarch64-a-b-kernel.h | 19 ++++++++++
 tests/migration/migration-test.h     |  5 +++
 6 files changed, 147 insertions(+), 8 deletions(-)
 create mode 100644 tests/migration/aarch64-a-b-kernel.S
 create mode 100644 tests/migration/aarch64-a-b-kernel.h

tests/Makefile.include +1 -0

index a1bcbffe12..df9f64438f 100644
@@ -372,6 +372,7 @@ check-qtest-arm-y += tests/sdhci-test$(EXESUF)
 check-qtest-aarch64-y = tests/numa-test$(EXESUF)
 check-qtest-aarch64-y += tests/sdhci-test$(EXESUF)
 check-qtest-aarch64-y += tests/boot-serial-test$(EXESUF)
+check-qtest-aarch64-y += tests/migration-test$(EXESUF)
 
 check-qtest-microblazeel-y = $(check-qtest-microblaze-y)
 

tests/migration-test.c +41 -6

index e2e06ed337..a4f6732a59 100644
@@ -11,6 +11,7 @@
  */
 
 #include "qemu/osdep.h"
+#include <sys/utsname.h>
 
 #include "libqtest.h"
 #include "qapi/qmp/qdict.h"

@@ -23,8 +24,8 @@
 
 #include "migration/migration-test.h"
 
-const unsigned start_address = TEST_MEM_START;
-const unsigned end_address = TEST_MEM_END;
+unsigned start_address = TEST_MEM_START;
+unsigned end_address = TEST_MEM_END;
 bool got_stop;
 
 #if defined(__linux__)

@@ -81,12 +82,13 @@ static const char *tmpfs;
  * outputting a 'B' every so often if it's still running.
  */
 #include "tests/migration/x86-a-b-bootblock.h"
+#include "tests/migration/aarch64-a-b-kernel.h"
 
-static void init_bootfile_x86(const char *bootpath)
+static void init_bootfile(const char *bootpath, void *content)
 {
     FILE *bootfile = fopen(bootpath, "wb");
 
-    g_assert_cmpint(fwrite(x86_bootsect, 512, 1, bootfile), ==, 1);
+    g_assert_cmpint(fwrite(content, 512, 1, bootfile), ==, 1);
     fclose(bootfile);
 }
 

@@ -393,7 +395,7 @@ static void test_migrate_start(QTestState **from, QTestState **to,
     got_stop = false;
 
     if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
-        init_bootfile_x86(bootpath);
+        init_bootfile(bootpath, x86_bootsect);
         cmd_src = g_strdup_printf("-machine accel=%s -m 150M"
                                   " -name source,debug-threads=on"
                                   " -serial file:%s/src_serial"

@@ -422,6 +424,39 @@ static void test_migrate_start(QTestState **from, QTestState **to,
                                   " -serial file:%s/dest_serial"
                                   " -incoming %s",
                                   accel, tmpfs, uri);
+    } else if (strcmp(arch, "aarch64") == 0) {
+        const char *cpu;
+        const char *gic_ver;
+        struct utsname utsname;
+
+        /* kvm and tcg need different cpu and gic-version configs */
+        if (access("/dev/kvm", F_OK) == 0 && uname(&utsname) == 0 &&
+            strcmp(utsname.machine, "aarch64") == 0) {
+            accel = "kvm";
+            cpu = "host";
+            gic_ver = "host";
+        } else {
+            accel = "tcg";
+            cpu = "cortex-a57";
+            gic_ver = "2";
+        }
+
+        init_bootfile(bootpath, aarch64_kernel);
+        cmd_src = g_strdup_printf("-machine virt,accel=%s,gic-version=%s "
+                                  "-name vmsource,debug-threads=on -cpu %s "
+                                  "-m 150M -serial file:%s/src_serial "
+                                  "-kernel %s ",
+                                  accel, gic_ver, cpu, tmpfs, bootpath);
+        cmd_dst = g_strdup_printf("-machine virt,accel=%s,gic-version=%s "
+                                  "-name vmdest,debug-threads=on -cpu %s "
+                                  "-m 150M -serial file:%s/dest_serial "
+                                  "-kernel %s "
+                                  "-incoming %s ",
+                                  accel, gic_ver, cpu, tmpfs, bootpath, uri);
+
+        /* aarch64 virt machine physical memory starts at 0x40000000 */
+        start_address = ARM_TEST_MEM_START;
+        end_address = ARM_TEST_MEM_END;
     } else {
         g_assert_not_reached();
     }

@@ -506,7 +541,7 @@ static void test_deprecated(void)
 {
     QTestState *from;
 
-    from = qtest_start("");
+    from = qtest_start("-machine none");
 
     deprecated_set_downtime(from, 0.12345);
     deprecated_set_speed(from, "12345");

tests/migration/Makefile +2 -1

index b768d0729d..b72d41367f 100644
@@ -15,6 +15,7 @@ cross-gcc = $(firstword $(wildcard $(patsubst %ld,%gcc,$(call cross-ld,$(1)))))
 find-cross-prefix = $(subst gcc,,$(notdir $(call cross-gcc,$(1))))
 
 x86_64_cross_prefix := $(call find-cross-prefix,x86_64)
+aarch64_cross_prefix := $(call find-cross-prefix,aarch64)
 
 export __note
 override define __note

@@ -25,7 +26,7 @@ override define __note
  */
 endef
 
-all: x86-a-b-bootblock.h
+all: x86-a-b-bootblock.h aarch64-a-b-kernel.h
 
 x86-a-b-bootblock.h: x86-a-b-bootblock.S
 	$(x86_64_cross_prefix)gcc -m32 -march=i486 -c $< -o x86.o

@@ -34,5 +35,12 @@ x86-a-b-bootblock.h: x86-a-b-bootblock.S
 	echo "$$__note" > $@
 	xxd -i x86.bootsect | sed -e 's/.*int.*//' >> $@
 

Quoted 8 lines

tests/migration/Makefile x86-a-b-bootblock.h: x86-a-b-bootblock.S · line 40

Quoted 3 lines

tests/migration/Makefile +3 -0

+aarch64-a-b-kernel.h: aarch64-a-b-kernel.S
+	$(aarch64_cross_prefix)gcc -o aarch64.elf -nostdlib \
+		-Wl,--build-id=none,-Ttext=40080000 $<

Adding the arm64 Linux kernel offset here is a bit subtle. And, since the TEST_MEM_START is at 1M, that only leaves 512K for test code and data. I think you may want to define this offset somewhere, making it less subtle, and then also factor it in when computing the test mem start.

I have fixed most parts based on your review comments, except for this one. I think the section address, -Ttext=, doesn't matter in this case. Such info is not present aarch64.kernel; plus QEMU loads the kernel into

the loader_start address, which is the physical memory base (0x40000000, see virt.c). So the space to store kernel binary is 1MB, which should be large enough to prevent aarch64-a-b-kernel.S from changing code.

Anyway I think we are fine to remove "-Ttext=40080000" here.

Quoted 174 lines · Wei Huang

Quoted 162 lines · Andrew Jones

Quoted 161 lines · Wei Huang

This patch adds migration test support for aarch64. The test code, which implements the same functionality as x86, is booted as a kernel in qemu. Here are the design choices we make for aarch64:

* We choose this -kernel approach because aarch64 QEMU doesn't provide a built-in fw like x86 does. So instead of relying on a boot loader, we use -kernel approach for aarch64.
* The serial output is sent to PL011 directly.
* The physical memory base for mach-virt machine is 0x40000000. We change the start_address and end_address for aarch64.

In addition to providing the binary, this patch also includes the source code and the build script in tests/migration/. So users can change the source and/or re-compile the binary as they wish.

Signed-off-by Wei Huang <[email protected]>

---
 tests/Makefile.include               |  1 +
 tests/migration-test.c               | 47 +++++++++++++++++++++---
 tests/migration/Makefile             | 12 +++++-
 tests/migration/aarch64-a-b-kernel.S | 71 ++++++++++++++++++++++++++++++++++++
 tests/migration/aarch64-a-b-kernel.h | 19 ++++++++++
 tests/migration/migration-test.h     |  5 +++
 6 files changed, 147 insertions(+), 8 deletions(-)
 create mode 100644 tests/migration/aarch64-a-b-kernel.S
 create mode 100644 tests/migration/aarch64-a-b-kernel.h

tests/Makefile.include +1 -0

index a1bcbffe12..df9f64438f 100644
@@ -372,6 +372,7 @@ check-qtest-arm-y += tests/sdhci-test$(EXESUF)
 check-qtest-aarch64-y = tests/numa-test$(EXESUF)
 check-qtest-aarch64-y += tests/sdhci-test$(EXESUF)
 check-qtest-aarch64-y += tests/boot-serial-test$(EXESUF)
+check-qtest-aarch64-y += tests/migration-test$(EXESUF)
 
 check-qtest-microblazeel-y = $(check-qtest-microblaze-y)
 

tests/migration-test.c +41 -6

index e2e06ed337..a4f6732a59 100644
@@ -11,6 +11,7 @@
  */
 
 #include "qemu/osdep.h"
+#include <sys/utsname.h>
 
 #include "libqtest.h"
 #include "qapi/qmp/qdict.h"

@@ -23,8 +24,8 @@
 
 #include "migration/migration-test.h"
 
-const unsigned start_address = TEST_MEM_START;
-const unsigned end_address = TEST_MEM_END;
+unsigned start_address = TEST_MEM_START;
+unsigned end_address = TEST_MEM_END;
 bool got_stop;
 
 #if defined(__linux__)

@@ -81,12 +82,13 @@ static const char *tmpfs;
  * outputting a 'B' every so often if it's still running.
  */
 #include "tests/migration/x86-a-b-bootblock.h"
+#include "tests/migration/aarch64-a-b-kernel.h"
 
-static void init_bootfile_x86(const char *bootpath)
+static void init_bootfile(const char *bootpath, void *content)
 {
     FILE *bootfile = fopen(bootpath, "wb");
 
-    g_assert_cmpint(fwrite(x86_bootsect, 512, 1, bootfile), ==, 1);
+    g_assert_cmpint(fwrite(content, 512, 1, bootfile), ==, 1);
     fclose(bootfile);
 }
 

@@ -393,7 +395,7 @@ static void test_migrate_start(QTestState **from, QTestState **to,
     got_stop = false;
 
     if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
-        init_bootfile_x86(bootpath);
+        init_bootfile(bootpath, x86_bootsect);
         cmd_src = g_strdup_printf("-machine accel=%s -m 150M"
                                   " -name source,debug-threads=on"
                                   " -serial file:%s/src_serial"

@@ -422,6 +424,39 @@ static void test_migrate_start(QTestState **from, QTestState **to,
                                   " -serial file:%s/dest_serial"
                                   " -incoming %s",
                                   accel, tmpfs, uri);
+    } else if (strcmp(arch, "aarch64") == 0) {
+        const char *cpu;
+        const char *gic_ver;
+        struct utsname utsname;
+
+        /* kvm and tcg need different cpu and gic-version configs */
+        if (access("/dev/kvm", F_OK) == 0 && uname(&utsname) == 0 &&
+            strcmp(utsname.machine, "aarch64") == 0) {
+            accel = "kvm";
+            cpu = "host";
+            gic_ver = "host";
+        } else {
+            accel = "tcg";
+            cpu = "cortex-a57";
+            gic_ver = "2";
+        }
+
+        init_bootfile(bootpath, aarch64_kernel);
+        cmd_src = g_strdup_printf("-machine virt,accel=%s,gic-version=%s "
+                                  "-name vmsource,debug-threads=on -cpu %s "
+                                  "-m 150M -serial file:%s/src_serial "
+                                  "-kernel %s ",
+                                  accel, gic_ver, cpu, tmpfs, bootpath);
+        cmd_dst = g_strdup_printf("-machine virt,accel=%s,gic-version=%s "
+                                  "-name vmdest,debug-threads=on -cpu %s "
+                                  "-m 150M -serial file:%s/dest_serial "
+                                  "-kernel %s "
+                                  "-incoming %s ",
+                                  accel, gic_ver, cpu, tmpfs, bootpath, uri);
+
+        /* aarch64 virt machine physical memory starts at 0x40000000 */
+        start_address = ARM_TEST_MEM_START;
+        end_address = ARM_TEST_MEM_END;
     } else {
         g_assert_not_reached();
     }

@@ -506,7 +541,7 @@ static void test_deprecated(void)
 {
     QTestState *from;
 
-    from = qtest_start("");
+    from = qtest_start("-machine none");
 
     deprecated_set_downtime(from, 0.12345);
     deprecated_set_speed(from, "12345");

tests/migration/Makefile +2 -1

index b768d0729d..b72d41367f 100644
@@ -15,6 +15,7 @@ cross-gcc = $(firstword $(wildcard $(patsubst %ld,%gcc,$(call cross-ld,$(1)))))
 find-cross-prefix = $(subst gcc,,$(notdir $(call cross-gcc,$(1))))
 
 x86_64_cross_prefix := $(call find-cross-prefix,x86_64)
+aarch64_cross_prefix := $(call find-cross-prefix,aarch64)
 
 export __note
 override define __note

@@ -25,7 +26,7 @@ override define __note
  */
 endef
 
-all: x86-a-b-bootblock.h
+all: x86-a-b-bootblock.h aarch64-a-b-kernel.h
 
 x86-a-b-bootblock.h: x86-a-b-bootblock.S
 	$(x86_64_cross_prefix)gcc -m32 -march=i486 -c $< -o x86.o

@@ -34,5 +35,12 @@ x86-a-b-bootblock.h: x86-a-b-bootblock.S
 	echo "$$__note" > $@
 	xxd -i x86.bootsect | sed -e 's/.*int.*//' >> $@
 

Quoted 8 lines

tests/migration/Makefile x86-a-b-bootblock.h: x86-a-b-bootblock.S · line 40

Quoted 3 lines

tests/migration/Makefile +3 -0

+aarch64-a-b-kernel.h: aarch64-a-b-kernel.S
+	$(aarch64_cross_prefix)gcc -o aarch64.elf -nostdlib \
+		-Wl,--build-id=none,-Ttext=40080000 $<

Adding the arm64 Linux kernel offset here is a bit subtle. And, since the TEST_MEM_START is at 1M, that only leaves 512K for test code and data. I think you may want to define this offset somewhere, making it less subtle, and then also factor it in when computing the test mem start.

Quoted 3 lines

I have fixed most parts based on your review comments, except for this one. I think the section address, -Ttext=, doesn't matter in this case. Such info is not present aarch64.kernel; plus QEMU loads the kernel into

In this case it doesn't matter because your code only uses pc-relative addresses. It's pretty safe to assume the compiler will only emit pc- relative addresses for code like this, so that's probably fine.

Quoted 3 lines

the loader_start address, which is the physical memory base (0x40000000, see virt.c). So the space to store kernel binary is 1MB, which should be large enough to prevent aarch64-a-b-kernel.S from changing code.

No, it loads the kernel at 0x40000000 + 0x80000, see hw/arm/boot.c:load_aarch64_image() and KERNEL64_LOAD_ADDR.

Quoted 2 lines

Anyway I think we are fine to remove "-Ttext=40080000" here.

Fine by me, but you might want to add a comment saying the code *must* only compile to using pc-relative addresses.

Thanks,
drew