From b0cdef3211b8a961699b301663ee3b3cf46a5148 Mon Sep 17 00:00:00 2001
From: whitequark <whitequark@whitequark.org>
Date: Mon, 6 Mar 2017 16:01:28 +0000
Subject: [PATCH] firmware: implement hotswap through artiq_coreboot tool.

---
 artiq/coredevice/comm_kernel.py          |  6 ++++
 artiq/firmware/libboard/hotswap.rs       | 31 ++++++++++++++++++++
 artiq/firmware/libboard/lib.rs           |  2 ++
 artiq/firmware/libproto/session_proto.rs |  3 ++
 artiq/firmware/runtime/session.rs        |  4 +++
 artiq/frontend/artiq_coreboot.py         | 36 ++++++++++++++++++++++++
 setup.py                                 |  1 +
 7 files changed, 83 insertions(+)
 create mode 100644 artiq/firmware/libboard/hotswap.rs
 create mode 100644 artiq/frontend/artiq_coreboot.py

diff --git a/artiq/coredevice/comm_kernel.py b/artiq/coredevice/comm_kernel.py
index de3c55d9f..63fe42328 100644
--- a/artiq/coredevice/comm_kernel.py
+++ b/artiq/coredevice/comm_kernel.py
@@ -34,6 +34,8 @@ class _H2DMsgType(Enum):
     FLASH_ERASE_REQUEST = 11
     FLASH_REMOVE_REQUEST = 12
 
+    HOTSWAP = 14
+
 
 class _D2HMsgType(Enum):
     LOG_REPLY = 1
@@ -326,6 +328,10 @@ class CommKernel:
 
         self._read_empty(_D2HMsgType.FLASH_OK_REPLY)
 
+    def hotswap(self, image):
+        self._write_header(_H2DMsgType.HOTSWAP)
+        self._write_bytes(image)
+
     def load(self, kernel_library):
         self._write_header(_H2DMsgType.LOAD_KERNEL)
         self._write_bytes(kernel_library)
diff --git a/artiq/firmware/libboard/hotswap.rs b/artiq/firmware/libboard/hotswap.rs
new file mode 100644
index 000000000..5fb2fd749
--- /dev/null
+++ b/artiq/firmware/libboard/hotswap.rs
@@ -0,0 +1,31 @@
+use irq;
+
+pub unsafe fn run(new_code: &[u8]) -> ! {
+    irq::set_ie(false);
+    #[cfg(target_arch="or1k")]
+    asm!(r#"
+        # This loop overwrites itself, but it's structured in such a way
+        # that before that happens, it loads itself into I$$ fully.
+        l.movhi    r4, hi(_ftext)
+        l.ori      r4, r4, lo(_ftext)
+        l.or       r7, r4, r0
+    0:  l.sfnei    r5, 0
+        l.bf       1f
+        l.nop
+        l.jr       r7
+        l.nop
+    1:  l.lwz      r6, 0(r3)
+        l.sw       0(r4), r6
+        l.addi     r3, r3, 4
+        l.addi     r4, r4, 4
+        l.addi     r5, r5, -4
+        l.bf       0b
+        l.nop
+    "#
+    :
+    : "{r3}"(new_code.as_ptr() as usize),
+      "{r5}"(new_code.len())
+    :
+    : "volatile");
+    loop {}
+}
diff --git a/artiq/firmware/libboard/lib.rs b/artiq/firmware/libboard/lib.rs
index 999926cb0..499e4b0e1 100644
--- a/artiq/firmware/libboard/lib.rs
+++ b/artiq/firmware/libboard/lib.rs
@@ -35,6 +35,8 @@ mod ad9154_reg;
 #[cfg(has_ad9154)]
 pub mod ad9154;
 
+pub mod hotswap;
+
 #[cfg(feature = "uart_console")]
 pub use uart_console::Console;
 
diff --git a/artiq/firmware/libproto/session_proto.rs b/artiq/firmware/libproto/session_proto.rs
index 35afbe5fb..31f3cc911 100644
--- a/artiq/firmware/libproto/session_proto.rs
+++ b/artiq/firmware/libproto/session_proto.rs
@@ -46,6 +46,8 @@ pub enum Request {
     FlashWrite  { key: String, value: Vec<u8> },
     FlashRemove { key: String },
     FlashErase,
+
+    Hotswap(Vec<u8>),
 }
 
 impl Request {
@@ -97,6 +99,7 @@ impl Request {
             12 => Request::FlashRemove {
                 key: reader.read_string()?
             },
+            14 => Request::Hotswap(reader.read_bytes()?),
             _  => return Err(io::Error::new(io::ErrorKind::InvalidData, "unknown request type"))
         })
     }
diff --git a/artiq/firmware/runtime/session.rs b/artiq/firmware/runtime/session.rs
index 9ed0ba3e2..370a9ac34 100644
--- a/artiq/firmware/runtime/session.rs
+++ b/artiq/firmware/runtime/session.rs
@@ -268,6 +268,10 @@ fn process_host_message(io: &Io,
             }
         }
 
+        // artiq_coreboot
+        host::Request::Hotswap(binary) =>
+            unsafe { board::hotswap::run(&binary) },
+
         // artiq_run/artiq_master
         host::Request::SwitchClock(clk) => {
             if session.running() {
diff --git a/artiq/frontend/artiq_coreboot.py b/artiq/frontend/artiq_coreboot.py
new file mode 100644
index 000000000..b02c78793
--- /dev/null
+++ b/artiq/frontend/artiq_coreboot.py
@@ -0,0 +1,36 @@
+#!/usr/bin/env python3
+
+import argparse
+import struct
+
+from artiq.tools import verbosity_args, init_logger
+from artiq.master.databases import DeviceDB
+from artiq.master.worker_db import DeviceManager
+
+
+def get_argparser():
+    parser = argparse.ArgumentParser(description="ARTIQ core device hotswap tool")
+
+    verbosity_args(parser)
+    parser.add_argument("--device-db", default="device_db.pyon",
+                       help="device database file (default: '%(default)s')")
+
+    parser.add_argument("image", metavar="IMAGE", type=argparse.FileType('rb'),
+                        help="runtime image to be executed")
+
+    return parser
+
+
+def main():
+    args = get_argparser().parse_args()
+    init_logger(args)
+    device_mgr = DeviceManager(DeviceDB(args.device_db))
+    try:
+        comm = device_mgr.get("comm")
+        comm.check_system_info()
+        comm.hotswap(args.image.read())
+    finally:
+        device_mgr.close_devices()
+
+if __name__ == "__main__":
+    main()
diff --git a/setup.py b/setup.py
index 1d5a9fd57..e5b6c5b8f 100755
--- a/setup.py
+++ b/setup.py
@@ -24,6 +24,7 @@ console_scripts = [
     "artiq_coreanalyzer=artiq.frontend.artiq_coreanalyzer:main",
     "artiq_coreconfig=artiq.frontend.artiq_coreconfig:main",
     "artiq_corelog=artiq.frontend.artiq_corelog:main",
+    "artiq_coreboot=artiq.frontend.artiq_coreboot:main",
     "artiq_ctlmgr=artiq.frontend.artiq_ctlmgr:main",
     "artiq_devtool=artiq.frontend.artiq_devtool:main",
     "artiq_influxdb=artiq.frontend.artiq_influxdb:main",