From 5aaab2879d0fbbb0b3665d5c5566c88e74e02a36 Mon Sep 17 00:00:00 2001
From: Tau <tau@nowhere>
Date: Wed, 7 Nov 2018 16:45:48 -0500
Subject: [PATCH] nu/eeprom.c: Add emulated EEPROM device

---
 nu/eeprom.c    | 154 +++++++++++++++++++++++++++++++++++++++++++++++++
 nu/eeprom.h    |  12 ++++
 nu/guid.c      |   2 +
 nu/meson.build |   2 +
 4 files changed, 170 insertions(+)
 create mode 100644 nu/eeprom.c
 create mode 100644 nu/eeprom.h

diff --git a/nu/eeprom.c b/nu/eeprom.c
new file mode 100644
index 0000000..88400ce
--- /dev/null
+++ b/nu/eeprom.c
@@ -0,0 +1,154 @@
+#include <windows.h>
+
+#include "hook/iohook.h"
+
+#include "nu/eeprom.h"
+#include "nu/nvram.h"
+
+#include "util/dprintf.h"
+#include "util/setupapi.h"
+
+static HRESULT eeprom_handle_irp(struct irp *irp);
+static HRESULT eeprom_handle_open(struct irp *irp);
+static HRESULT eeprom_handle_close(struct irp *irp);
+static HRESULT eeprom_handle_ioctl(struct irp *irp);
+static HRESULT eeprom_handle_read(struct irp *irp);
+static HRESULT eeprom_handle_write(struct irp *irp);
+
+static HRESULT eeprom_ioctl_get_geometry(struct irp *irp);
+
+static HANDLE eeprom_file;
+
+HRESULT eeprom_hook_init(void)
+{
+    HRESULT hr;
+
+    hr = nvram_open_file(&eeprom_file, L"DEVICE\\eeprom.bin", 0x2000);
+
+    if (FAILED(hr)) {
+        return hr;
+    }
+
+    hr = iohook_push_handler(eeprom_handle_irp);
+
+    if (FAILED(hr)) {
+        return hr;
+    }
+
+    hr = setupapi_add_phantom_dev(&eeprom_guid, L"$eeprom");
+
+    if (FAILED(hr)) {
+        return hr;
+    }
+
+    return S_OK;
+}
+
+static HRESULT eeprom_handle_irp(struct irp *irp)
+{
+    assert(irp != NULL);
+
+    if (irp->op != IRP_OP_OPEN && irp->fd != eeprom_file) {
+        return iohook_invoke_next(irp);
+    }
+
+    switch (irp->op) {
+    case IRP_OP_OPEN:   return eeprom_handle_open(irp);
+    case IRP_OP_CLOSE:  return eeprom_handle_close(irp);
+    case IRP_OP_IOCTL:  return eeprom_handle_ioctl(irp);
+    case IRP_OP_READ:   return eeprom_handle_read(irp);
+    case IRP_OP_WRITE:  return eeprom_handle_write(irp);
+    default:            return iohook_invoke_next(irp);
+    }
+}
+
+static HRESULT eeprom_handle_open(struct irp *irp)
+{
+    if (wcscmp(irp->open_filename, L"$eeprom") != 0) {
+        return iohook_invoke_next(irp);
+    }
+
+    dprintf("EEPROM: Open device\n");
+    irp->fd = eeprom_file;
+
+    return S_OK;
+}
+
+static HRESULT eeprom_handle_close(struct irp *irp)
+{
+    dprintf("EEPROM: Close device\n");
+
+    return S_OK;
+}
+
+static HRESULT eeprom_handle_ioctl(struct irp *irp)
+{
+    switch (irp->ioctl) {
+    case IOCTL_DISK_GET_DRIVE_GEOMETRY:
+        return eeprom_ioctl_get_geometry(irp);
+
+    default:
+        dprintf("EEPROM: Unknown ioctl %x, write %i read %i\n",
+                irp->ioctl,
+                irp->write.nbytes,
+                irp->read.nbytes);
+
+        return HRESULT_FROM_WIN32(ERROR_INVALID_FUNCTION);
+    }
+}
+
+static HRESULT eeprom_ioctl_get_geometry(struct irp *irp)
+{
+    DISK_GEOMETRY *out;
+
+    if (irp->read.nbytes < sizeof(*out)) {
+        dprintf("EEPROM: Invalid ioctl response buffer size\n");
+
+        return HRESULT_FROM_WIN32(ERROR_INSUFFICIENT_BUFFER);
+    }
+
+    dprintf("EEPROM: Get geometry\n");
+
+    /* Not the real values, just bullshitting something for now */
+
+    out = (DISK_GEOMETRY *) irp->read.bytes;
+    out->Cylinders.QuadPart = 0x800;
+    out->MediaType = 0;
+    out->TracksPerCylinder = 1;
+    out->SectorsPerTrack = 2;
+    out->BytesPerSector = 4;
+
+    irp->read.pos = sizeof(*out);
+
+    return S_OK;
+}
+
+static HRESULT eeprom_handle_read(struct irp *irp)
+{
+    if (irp->ovl == NULL) {
+        dprintf("EEPROM: Synchronous read..?\n");
+
+        return E_UNEXPECTED;
+    }
+
+    dprintf("EEPROM: Read off %x len %x\n",
+            (int) irp->ovl->Offset,
+            irp->read.nbytes);
+
+    return iohook_invoke_next(irp);
+}
+
+static HRESULT eeprom_handle_write(struct irp *irp)
+{
+    if (irp->ovl == NULL) {
+        dprintf("EEPROM: Synchronous write..?\n");
+
+        return E_UNEXPECTED;
+    }
+
+    dprintf("EEPROM: Write off %x len %x\n",
+            (int) irp->ovl->Offset,
+            irp->write.nbytes);
+
+    return iohook_invoke_next(irp);
+}
diff --git a/nu/eeprom.h b/nu/eeprom.h
new file mode 100644
index 0000000..0d1802d
--- /dev/null
+++ b/nu/eeprom.h
@@ -0,0 +1,12 @@
+#pragma once
+
+#include <windows.h>
+
+DEFINE_GUID(
+        eeprom_guid,
+        0xB7970F0C,
+        0x31C4,
+        0x45FF,
+        0x96, 0x18, 0x0A, 0x24, 0x00, 0x94, 0xB2, 0x71);
+
+HRESULT eeprom_hook_init(void);
diff --git a/nu/guid.c b/nu/guid.c
index 3bb6ac4..f2f706f 100644
--- a/nu/guid.c
+++ b/nu/guid.c
@@ -1,2 +1,4 @@
 #include <windows.h>
 #include <initguid.h>
+
+#include "nu/eeprom.h"
diff --git a/nu/meson.build b/nu/meson.build
index 771292e..f827bb9 100644
--- a/nu/meson.build
+++ b/nu/meson.build
@@ -8,6 +8,8 @@ nu_lib = static_library(
         capnhook.get_variable('hooklib_dep'),
     ],
     sources : [
+        'eeprom.c',
+        'eeprom.h',
         'guid.c',
         'nvram.c',
         'nvram.h',