Merge remote-tracking branch 'remotes/philmd-gitlab/tags/avr-port-20200711' into staging

8bit AVR port from Michael Rolnik.

Michael started to work on the AVR port few years ago [*] and kept
improving the code over various series.

List of people who help him (in chronological order):
- Richard Henderson
- Sarah Harris and Edward Robbins
- Philippe Mathieu-Daudé and Aleksandar Markovic
- Pavel Dovgalyuk
- Thomas Huth

[*] The oldest contribution I could find on the list is from 2016:
https://lists.nongnu.org/archive/html/qemu-devel/2016-06/msg02985.html

Tests included:

$ avocado --show=app run -t arch:avr tests/acceptance/
Fetching asset from tests/acceptance/machine_avr6.py:AVR6Machine.test_freertos
 (1/1) tests/acceptance/machine_avr6.py:AVR6Machine.test_freertos: PASS (2.13 s)
RESULTS    : PASS 1 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 0
JOB TIME   : 2.35 s

$ make check-qtest-avr
  TEST    check-qtest-avr: tests/qtest/boot-serial-test
  TEST    check-qtest-avr: tests/qtest/cdrom-test
  TEST    check-qtest-avr: tests/qtest/device-introspect-test
  TEST    check-qtest-avr: tests/qtest/machine-none-test
  TEST    check-qtest-avr: tests/qtest/qmp-test
  TEST    check-qtest-avr: tests/qtest/qmp-cmd-test
  TEST    check-qtest-avr: tests/qtest/qom-test
  TEST    check-qtest-avr: tests/qtest/test-hmp
  TEST    check-qtest-avr: tests/qtest/qos-test

CI results:
. https://cirrus-ci.com/build/5697049146425344
. https://gitlab.com/philmd/qemu/-/pipelines/165328058
. https://travis-ci.org/github/philmd/qemu/builds/705817933
. https://app.shippable.com/github/philmd/qemu/runs/822/summary/console

# gpg: Signature made Sat 11 Jul 2020 10:03:11 BST
# gpg:                using RSA key FAABE75E12917221DCFD6BB2E3E32C2CDEADC0DE
# gpg: Good signature from "Philippe Mathieu-Daudé (F4BUG) <f4bug@amsat.org>" [full]
# Primary key fingerprint: FAAB E75E 1291 7221 DCFD  6BB2 E3E3 2C2C DEAD C0DE

* remotes/philmd-gitlab/tags/avr-port-20200711: (32 commits)
  target/avr/disas: Fix store instructions display order
  target/avr/cpu: Fix $PC displayed address
  target/avr/cpu: Drop tlb_flush() in avr_cpu_reset()
  target/avr: Add section into QEMU documentation
  tests/acceptance: Test the Arduino MEGA2560 board
  tests/boot-serial: Test some Arduino boards (AVR based)
  hw/avr: Add limited support for some Arduino boards
  hw/avr: Add some ATmega microcontrollers
  hw/avr: Add support for loading ELF/raw binaries
  hw/misc: avr: Add limited support for power reduction device
  hw/timer: avr: Add limited support for 16-bit timer peripheral
  hw/char: avr: Add limited support for USART peripheral
  tests/machine-none: Add AVR support
  target/avr: Register AVR support with the rest of QEMU
  target/avr: Add support for disassembling via option '-d in_asm'
  target/avr: Initialize TCG register variables
  target/avr: Add instruction translation - CPU main translation function
  target/avr: Add instruction translation - MCU Control Instructions
  target/avr: Add instruction translation - Bit and Bit-test Instructions
  target/avr: Add instruction translation - Data Transfer Instructions
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 115 insertions, 0 deletions

diff --git a/hw/avr/boot.c b/hw/avr/boot.c
new file mode 100644
index 0000000000..6fbcde4061
--- /dev/null
+++ b/hw/avr/boot.c
@@ -0,0 +1,115 @@
+/*
+ * AVR loader helpers
+ *
+ * Copyright (c) 2019-2020 Philippe Mathieu-Daudé
+ *
+ * This work is licensed under the terms of the GNU GPLv2 or later.
+ * See the COPYING file in the top-level directory.
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "hw/loader.h"
+#include "elf.h"
+#include "boot.h"
+#include "qemu/error-report.h"
+
+static const char *avr_elf_e_flags_to_cpu_type(uint32_t flags)
+{
+    switch (flags & EF_AVR_MACH) {
+    case bfd_mach_avr1:
+        return AVR_CPU_TYPE_NAME("avr1");
+    case bfd_mach_avr2:
+        return AVR_CPU_TYPE_NAME("avr2");
+    case bfd_mach_avr25:
+        return AVR_CPU_TYPE_NAME("avr25");
+    case bfd_mach_avr3:
+        return AVR_CPU_TYPE_NAME("avr3");
+    case bfd_mach_avr31:
+        return AVR_CPU_TYPE_NAME("avr31");
+    case bfd_mach_avr35:
+        return AVR_CPU_TYPE_NAME("avr35");
+    case bfd_mach_avr4:
+        return AVR_CPU_TYPE_NAME("avr4");
+    case bfd_mach_avr5:
+        return AVR_CPU_TYPE_NAME("avr5");
+    case bfd_mach_avr51:
+        return AVR_CPU_TYPE_NAME("avr51");
+    case bfd_mach_avr6:
+        return AVR_CPU_TYPE_NAME("avr6");
+    case bfd_mach_avrtiny:
+        return AVR_CPU_TYPE_NAME("avrtiny");
+    case bfd_mach_avrxmega2:
+        return AVR_CPU_TYPE_NAME("xmega2");
+    case bfd_mach_avrxmega3:
+        return AVR_CPU_TYPE_NAME("xmega3");
+    case bfd_mach_avrxmega4:
+        return AVR_CPU_TYPE_NAME("xmega4");
+    case bfd_mach_avrxmega5:
+        return AVR_CPU_TYPE_NAME("xmega5");
+    case bfd_mach_avrxmega6:
+        return AVR_CPU_TYPE_NAME("xmega6");
+    case bfd_mach_avrxmega7:
+        return AVR_CPU_TYPE_NAME("xmega7");
+    default:
+        return NULL;
+    }
+}
+
+bool avr_load_firmware(AVRCPU *cpu, MachineState *ms,
+                       MemoryRegion *program_mr, const char *firmware)
+{
+    const char *filename;
+    int bytes_loaded;
+    uint64_t entry;
+    uint32_t e_flags;
+
+    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, firmware);
+    if (filename == NULL) {
+        error_report("Unable to find %s", firmware);
+        return false;
+    }
+
+    bytes_loaded = load_elf_ram_sym(filename,
+                                    NULL, NULL, NULL,
+                                    &entry, NULL, NULL,
+                                    &e_flags, 0, EM_AVR, 0, 0,
+                                    NULL, true, NULL);
+    if (bytes_loaded >= 0) {
+        /* If ELF file is provided, determine CPU type reading ELF e_flags. */
+        const char *elf_cpu = avr_elf_e_flags_to_cpu_type(e_flags);
+        const char *mcu_cpu_type = object_get_typename(OBJECT(cpu));
+        int cpu_len = strlen(mcu_cpu_type) - strlen(AVR_CPU_TYPE_SUFFIX);
+
+        if (entry) {
+            error_report("BIOS entry_point must be 0x0000 "
+                         "(ELF image '%s' has entry_point 0x%04" PRIx64 ")",
+                         firmware, entry);
+            return false;
+        }
+        if (!elf_cpu) {
+            warn_report("Could not determine CPU type for ELF image '%s', "
+                        "assuming '%.*s' CPU",
+                         firmware, cpu_len, mcu_cpu_type);
+            return true;
+        }
+        if (strcmp(elf_cpu, mcu_cpu_type)) {
+            error_report("Current machine: %s with '%.*s' CPU",
+                         MACHINE_GET_CLASS(ms)->desc, cpu_len, mcu_cpu_type);
+            error_report("ELF image '%s' is for '%.*s' CPU",
+                         firmware,
+                         (int)(strlen(elf_cpu) - strlen(AVR_CPU_TYPE_SUFFIX)),
+                         elf_cpu);
+            return false;
+        }
+    } else {
+        bytes_loaded = load_image_mr(filename, program_mr);
+    }
+    if (bytes_loaded < 0) {
+        error_report("Unable to load firmware image %s as ELF or raw binary",
+                     firmware);
+        return false;
+    }
+    return true;
+}