aarch64, fix gdb with linux-custom

README.md

@@ -291,7 +291,7 @@ And then tell GDB where the module was loaded with:
 
 The portability of the kernel and toolchains is amazing: change an option and most things magically work on completely different hardware.
 
-### ARM
+### arm
 
 First build:
 
@@ -312,7 +312,21 @@ TODOs:
 -   only managed to run in the terminal interface (but weirdly a blank QEMU window is still opened)
 -   GDB not connecting to KGDB. Possibly linked to `-serial stdio`. See also: <https://stackoverflow.com/questions/14155577/how-to-use-kgdb-on-arm>
 
-### MIPS
+### aarch64
+
+    ./run -a aarch64
+
+TODOs:
+
+-   GDB gives a ton of messages:
+
+        no module object found for ''
+
+    when you connect. `Ctrl + C` then `c` works though.
+
+-   How to add devices to `-M virt` as we did for `-M versatilepb`
+
+### mips64
 
     ./run -a mips64
 

kernel_config_fragment

@@ -53,12 +53,15 @@ CONFIG_SCHED_TRACER=y
 CONFIG_STACK_TRACER=y
 CONFIG_TRACER_SNAPSHOT=y
 
-# x86
+## x86
+
 # https://stackoverflow.com/questions/20069620/print-kernels-page-table-entries
 # cat /sys/kernel/debug/kernel_page_tables
 CONFIG_X86_PTDUMP=y
 
-# LEDs. ARM only.
+## ARM
+
+# LEDs:
 #
 #     cd /sys/class/leds/versatile:0
 #     cat max_brightness
@@ -109,8 +112,6 @@ CONFIG_GPIOLIB=y
 CONFIG_GPIO_SYSFS=y
 CONFIG_GPIO_PL061=y
 
-#     run -a arm
-#
 # In target:
 #
 #     modprobe dummy-irq irq=34
@@ -125,3 +126,12 @@ CONFIG_GPIO_PL061=y
 #
 # The IRQ number 34 was found by via dmesg on a previous "insmod /platform_device.ko".
 CONFIG_DUMMY_IRQ=m
+
+## aarch64
+
+# For some reason not selected by default as it was for arm, and pci modules fail to build.
+# Not that we have PCI working on ARM anyways.
+CONFIG_PCI=y
+
+# Like CONFIG_X86_PTDUMP for ARM.
+CONFIG_ARM64_PTDUMP=y

run

@@ -21,6 +21,9 @@ case "$arch" in
     # so let's stick to versatile for now.
     defconfig='qemu_arm_versatile_defconfig'
   ;;
+  'aarch64')
+    defconfig='qemu_aarch64_virt_defconfig'
+  ;;
   'mips64')
     defconfig='qemu_mips64r6_malta_defconfig'
   ;;

rungdb

@@ -23,7 +23,7 @@ fi
 
 buildroot_out_dir="$(pwd)/buildroot/output.${arch}~"
 gdb="${buildroot_out_dir}/host/usr/bin/${arch}-linux-gdb"
-cd "${buildroot_out_dir}/build"/linux-?.*.*/
+cd "${buildroot_out_dir}/build"/linux-custom/
 if "$kgdb"; then
     cmd="$gdb \
       -q \
@@ -51,7 +51,7 @@ else
         -ex 'lx-symbols ../kernel_module-1.0/'
       "
     ;;
-    'arm'|'mips64')
+    'arm'|'aarch64'|'mips64')
       cmd="$gdb \
         -q \
         -ex 'add-auto-load-safe-path $(pwd)' \
@@ -63,4 +63,5 @@ else
     ;;
   esac
 fi
+echo "$cmd"
 eval "$cmd"

runqemu

@@ -85,6 +85,23 @@ case "$arch" in
       $extra_flags
     "
   ;;
+  'aarch64')
+    if $kgdb; then
+      extra_append="$extra_append kgdboc=ttyAMA0,115200"
+    fi
+    cmd="$qemu_common \
+      -M virt \
+      -append 'root=/dev/sda $extra_append' \
+      -cpu cortex-a57 \
+      -device virtio-net-device,netdev=eth0 \
+      -drive file=${images_dir}/rootfs.cpio,if=scsi,format=raw \
+      -kernel ${images_dir}/Image \
+      -netdev user,id=eth0 \
+      -nographic \
+      -serial stdio \
+      $extra_flags
+    "
+  ;;
   'mips64')
     cmd="$qemu_common \
       -M malta \