Patchwork tests: Multiboot mmap test case

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Submitter Kevin Wolf
Date June 27, 2013, 1:31 p.m.
Message ID <1372339880-29125-1-git-send-email-kwolf@redhat.com>
Download mbox | patch
Permalink /patch/255078/
State New
Headers show

Comments

Kevin Wolf - June 27, 2013, 1:31 p.m.
This adds a test case for Multiboot memory map in the tests/multiboot
directory, where future i386 test kernels can be dropped. Because this
requires an x86 build host and an installed 32 bit libgcc, the test is
not part of a regular 'make check'.

The reference output for the test is verified against test runs of the
same multiboot kernel booted by some GRUB 0.97.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/multiboot/Makefile    |  18 ++++++
 tests/multiboot/libc.c      | 139 ++++++++++++++++++++++++++++++++++++++++++++
 tests/multiboot/libc.h      |  61 +++++++++++++++++++
 tests/multiboot/link.ld     |  19 ++++++
 tests/multiboot/mmap.c      |  56 ++++++++++++++++++
 tests/multiboot/mmap.out    |  93 +++++++++++++++++++++++++++++
 tests/multiboot/multiboot.h |  66 +++++++++++++++++++++
 tests/multiboot/run_test.sh |  81 ++++++++++++++++++++++++++
 tests/multiboot/start.S     |  51 ++++++++++++++++
 9 files changed, 584 insertions(+)
 create mode 100644 tests/multiboot/Makefile
 create mode 100644 tests/multiboot/libc.c
 create mode 100644 tests/multiboot/libc.h
 create mode 100644 tests/multiboot/link.ld
 create mode 100644 tests/multiboot/mmap.c
 create mode 100644 tests/multiboot/mmap.out
 create mode 100644 tests/multiboot/multiboot.h
 create mode 100755 tests/multiboot/run_test.sh
 create mode 100644 tests/multiboot/start.S

Patch

diff --git a/tests/multiboot/Makefile b/tests/multiboot/Makefile
new file mode 100644
index 0000000..34cdd81
--- /dev/null
+++ b/tests/multiboot/Makefile
@@ -0,0 +1,18 @@ 
+CC=gcc
+CCFLAGS=-m32 -Wall -Wextra -Werror -fno-stack-protector -nostdinc -fno-builtin
+ASFLAGS=-m32
+
+LD=ld
+LDFLAGS=-melf_i386 -T link.ld
+LIBS=$(shell $(CC) $(CCFLAGS) -print-libgcc-file-name)
+
+all: mmap.elf
+
+mmap.elf: start.o mmap.o libc.o
+	$(LD) $(LDFLAGS) -o $@ $^ $(LIBS)
+
+%.o: %.c
+	$(CC) $(CCFLAGS) -c -o $@ $^
+
+%.o: %.S
+	$(CC) $(ASFLAGS) -c -o $@ $^
diff --git a/tests/multiboot/libc.c b/tests/multiboot/libc.c
new file mode 100644
index 0000000..05abbd9
--- /dev/null
+++ b/tests/multiboot/libc.c
@@ -0,0 +1,139 @@ 
+/*
+ * Copyright (c) 2013 Kevin Wolf <kwolf@redhat.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "libc.h"
+
+static void print_char(char c)
+{
+    outb(0xe9, c);
+}
+
+static void print_str(char *s)
+{
+    while (*s) {
+        print_char(*s++);
+    }
+}
+
+static void print_num(uint64_t value, int base)
+{
+    char digits[] = "0123456789abcdef";
+    char buf[32] = { 0 };
+    int i = sizeof(buf) - 2;
+
+    do {
+        buf[i--] = digits[value % base];
+        value /= base;
+    } while (value);
+
+    print_str(&buf[i + 1]);
+}
+
+void printf(const char *fmt, ...)
+{
+    va_list ap;
+    uint64_t val;
+    char *str;
+    int base;
+    int has_long;
+    int alt_form;
+
+    va_start(ap, fmt);
+
+    for (; *fmt; fmt++) {
+        if (*fmt != '%') {
+            print_char(*fmt);
+            continue;
+        }
+        fmt++;
+
+        if (*fmt == '#') {
+            fmt++;
+            alt_form = 1;
+        } else {
+            alt_form = 0;
+        }
+
+        if (*fmt == 'l') {
+            fmt++;
+            if (*fmt == 'l') {
+                fmt++;
+                has_long = 2;
+            } else {
+                has_long = 1;
+            }
+        } else {
+            has_long = 0;
+        }
+
+        switch (*fmt) {
+        case 'x':
+        case 'p':
+            base = 16;
+            goto convert_number;
+        case 'd':
+        case 'i':
+        case 'u':
+            base = 10;
+            goto convert_number;
+        case 'o':
+            base = 8;
+            goto convert_number;
+
+        convert_number:
+            switch (has_long) {
+            case 0:
+                val = va_arg(ap, unsigned int);
+                break;
+            case 1:
+                val = va_arg(ap, unsigned long);
+                break;
+            case 2:
+                val = va_arg(ap, unsigned long long);
+                break;
+            }
+
+            if (alt_form && base == 16) {
+                print_str("0x");
+            }
+
+            print_num(val, base);
+            break;
+
+        case 's':
+            str = va_arg(ap, char*);
+            print_str(str);
+            break;
+        case '%':
+            print_char(*fmt);
+            break;
+        default:
+            print_char('%');
+            print_char(*fmt);
+            break;
+        }
+    }
+
+    va_end(ap);
+}
+
+
diff --git a/tests/multiboot/libc.h b/tests/multiboot/libc.h
new file mode 100644
index 0000000..80eec5b
--- /dev/null
+++ b/tests/multiboot/libc.h
@@ -0,0 +1,61 @@ 
+/*
+ * Copyright (c) 2013 Kevin Wolf <kwolf@redhat.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef LIBC_H
+#define LIBC_H
+
+/* Integer types */
+
+typedef unsigned long long uint64_t;
+typedef unsigned int uint32_t;
+typedef unsigned short uint16_t;
+typedef unsigned char uint8_t;
+
+typedef signed long long int64_t;
+typedef signed int int32_t;
+typedef signed short int16_t;
+typedef signed char int8_t;
+
+typedef uint32_t uintptr_t;
+
+
+/* stdarg.h */
+
+typedef __builtin_va_list       va_list;
+#define va_start(ap, X)         __builtin_va_start(ap, X)
+#define va_arg(ap, type)        __builtin_va_arg(ap, type)
+#define va_end(ap)              __builtin_va_end(ap)
+
+
+/* Port I/O functions */
+
+static inline void outb(uint16_t port, uint8_t data)
+{
+    asm volatile ("outb %0, %1" : : "a" (data), "Nd" (port));
+}
+
+
+/* Misc functions */
+
+void printf(const char *fmt, ...);
+
+#endif
diff --git a/tests/multiboot/link.ld b/tests/multiboot/link.ld
new file mode 100644
index 0000000..3d49b58
--- /dev/null
+++ b/tests/multiboot/link.ld
@@ -0,0 +1,19 @@ 
+ENTRY(_start)
+
+SECTIONS
+{
+    . = 0x100000;
+    .text : {
+        *(multiboot)
+        *(.text)
+    }
+    .data ALIGN(4096) : {
+        *(.data)
+    }
+    .rodata ALIGN(4096) : {
+        *(.rodata)
+    }
+    .bss ALIGN(4096) : {
+        *(.bss)
+    }
+}
diff --git a/tests/multiboot/mmap.c b/tests/multiboot/mmap.c
new file mode 100644
index 0000000..766b003
--- /dev/null
+++ b/tests/multiboot/mmap.c
@@ -0,0 +1,56 @@ 
+/*
+ * Copyright (c) 2013 Kevin Wolf <kwolf@redhat.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "libc.h"
+#include "multiboot.h"
+
+int test_main(uint32_t magic, struct mb_info *mbi)
+{
+    uintptr_t entry_addr;
+    struct mb_mmap_entry *entry;
+
+    (void) magic;
+
+    printf("Lower memory: %dk\n", mbi->mem_lower);
+    printf("Upper memory: %dk\n", mbi->mem_upper);
+
+    printf("\ne820 memory map:\n");
+
+    for (entry_addr = mbi->mmap_addr;
+         entry_addr < mbi->mmap_addr + mbi->mmap_length;
+         entry_addr += entry->size + 4)
+    {
+        entry = (struct mb_mmap_entry*) entry_addr;
+
+        printf("%#llx - %#llx: type %d [entry size: %d]\n",
+               entry->base_addr,
+               entry->base_addr + entry->length,
+               entry->type,
+               entry->size);
+    }
+
+    printf("\nmmap start:       %#x\n", mbi->mmap_addr);
+    printf("mmap end:         %#x\n", mbi->mmap_addr + mbi->mmap_length);
+    printf("real mmap end:    %#x\n", entry_addr);
+
+    return 0;
+}
diff --git a/tests/multiboot/mmap.out b/tests/multiboot/mmap.out
new file mode 100644
index 0000000..e70b6eb
--- /dev/null
+++ b/tests/multiboot/mmap.out
@@ -0,0 +1,93 @@ 
+
+
+
+=== Running test case: mmap.elf  ===
+
+Lower memory: 639k
+Upper memory: 130040k
+
+e820 memory map:
+0x0 - 0x9fc00: type 1 [entry size: 20]
+0x9fc00 - 0xa0000: type 2 [entry size: 20]
+0xf0000 - 0x100000: type 2 [entry size: 20]
+0x100000 - 0x7ffe000: type 1 [entry size: 20]
+0x7ffe000 - 0x8000000: type 2 [entry size: 20]
+0xfffc0000 - 0x100000000: type 2 [entry size: 20]
+
+mmap start:       0x9000
+mmap end:         0x9090
+real mmap end:    0x9090
+
+
+=== Running test case: mmap.elf -m 1.1M ===
+
+Lower memory: 639k
+Upper memory: 96k
+
+e820 memory map:
+0x0 - 0x9fc00: type 1 [entry size: 20]
+0x9fc00 - 0xa0000: type 2 [entry size: 20]
+0xf0000 - 0x100000: type 2 [entry size: 20]
+0x100000 - 0x118000: type 1 [entry size: 20]
+0x118000 - 0x11a000: type 2 [entry size: 20]
+0xfffc0000 - 0x100000000: type 2 [entry size: 20]
+
+mmap start:       0x9000
+mmap end:         0x9090
+real mmap end:    0x9090
+
+
+=== Running test case: mmap.elf -m 2G ===
+
+Lower memory: 639k
+Upper memory: 2096120k
+
+e820 memory map:
+0x0 - 0x9fc00: type 1 [entry size: 20]
+0x9fc00 - 0xa0000: type 2 [entry size: 20]
+0xf0000 - 0x100000: type 2 [entry size: 20]
+0x100000 - 0x7fffe000: type 1 [entry size: 20]
+0x7fffe000 - 0x80000000: type 2 [entry size: 20]
+0xfffc0000 - 0x100000000: type 2 [entry size: 20]
+
+mmap start:       0x9000
+mmap end:         0x9090
+real mmap end:    0x9090
+
+
+=== Running test case: mmap.elf -m 4G ===
+
+Lower memory: 639k
+Upper memory: 3668984k
+
+e820 memory map:
+0x0 - 0x9fc00: type 1 [entry size: 20]
+0x9fc00 - 0xa0000: type 2 [entry size: 20]
+0xf0000 - 0x100000: type 2 [entry size: 20]
+0x100000 - 0xdfffe000: type 1 [entry size: 20]
+0xdfffe000 - 0xe0000000: type 2 [entry size: 20]
+0xfffc0000 - 0x100000000: type 2 [entry size: 20]
+0x100000000 - 0x120000000: type 1 [entry size: 20]
+
+mmap start:       0x9000
+mmap end:         0x90a8
+real mmap end:    0x90a8
+
+
+=== Running test case: mmap.elf -m 8G ===
+
+Lower memory: 639k
+Upper memory: 3668984k
+
+e820 memory map:
+0x0 - 0x9fc00: type 1 [entry size: 20]
+0x9fc00 - 0xa0000: type 2 [entry size: 20]
+0xf0000 - 0x100000: type 2 [entry size: 20]
+0x100000 - 0xdfffe000: type 1 [entry size: 20]
+0xdfffe000 - 0xe0000000: type 2 [entry size: 20]
+0xfffc0000 - 0x100000000: type 2 [entry size: 20]
+0x100000000 - 0x220000000: type 1 [entry size: 20]
+
+mmap start:       0x9000
+mmap end:         0x90a8
+real mmap end:    0x90a8
diff --git a/tests/multiboot/multiboot.h b/tests/multiboot/multiboot.h
new file mode 100644
index 0000000..4eb1fbe
--- /dev/null
+++ b/tests/multiboot/multiboot.h
@@ -0,0 +1,66 @@ 
+/*
+ * Copyright (c) 2013 Kevin Wolf <kwolf@redhat.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MULTIBOOT_H
+#define MULTIBOOT_H
+
+#include "libc.h"
+
+struct mb_info {
+    uint32_t    flags;
+    uint32_t    mem_lower;
+    uint32_t    mem_upper;
+    uint32_t    boot_device;
+    uint32_t    cmdline;
+    uint32_t    mods_count;
+    uint32_t    mods_addr;
+    char        syms[16];
+    uint32_t    mmap_length;
+    uint32_t    mmap_addr;
+    uint32_t    drives_length;
+    uint32_t    drives_addr;
+    uint32_t    config_table;
+    uint32_t    boot_loader_name;
+    uint32_t    apm_table;
+    uint32_t    vbe_control_info;
+    uint32_t    vbe_mode_info;
+    uint16_t    vbe_mode;
+    uint16_t    vbe_interface_seg;
+    uint16_t    vbe_interface_off;
+    uint16_t    vbe_interface_len;
+} __attribute__((packed));
+
+struct mb_module {
+    uint32_t    mod_start;
+    uint32_t    mod_end;
+    uint32_t    string;
+    uint32_t    reserved;
+} __attribute__((packed));
+
+struct mb_mmap_entry {
+    uint32_t    size;
+    uint64_t    base_addr;
+    uint64_t    length;
+    uint32_t    type;
+} __attribute__((packed));
+
+#endif
diff --git a/tests/multiboot/run_test.sh b/tests/multiboot/run_test.sh
new file mode 100755
index 0000000..97a9a49
--- /dev/null
+++ b/tests/multiboot/run_test.sh
@@ -0,0 +1,81 @@ 
+#!/bin/bash
+
+# Copyright (c) 2013 Kevin Wolf <kwolf@redhat.com>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+QEMU=${QEMU:-"../../x86_64-softmmu/qemu-system-x86_64"}
+
+run_qemu() {
+    local kernel=$1
+    shift
+
+    echo -e "\n\n=== Running test case: $kernel $@ ===\n" >> test.log
+
+    $QEMU \
+        -kernel $kernel \
+        -display none \
+        -device isa-debugcon,chardev=stdio \
+        -chardev file,path=test.out,id=stdio \
+        -device isa-debug-exit,iobase=0xf4,iosize=0x4 \
+        "$@"
+    ret=$?
+
+    cat test.out >> test.log
+}
+
+mmap() {
+    run_qemu mmap.elf
+    run_qemu mmap.elf -m 1.1M
+    run_qemu mmap.elf -m 2G
+    run_qemu mmap.elf -m 4G
+    run_qemu mmap.elf -m 8G
+}
+
+
+make all
+
+for t in mmap; do
+
+    echo > test.log
+    $t
+
+    debugexit=$((ret & 0x1))
+    ret=$((ret >> 1))
+    pass=1
+
+    if [ $debugexit != 1 ]; then
+        echo -e "\e[31m ?? \e[0m $t (no debugexit used, exit code $ret)"
+        pass=0
+    elif [ $ret != 0 ]; then
+        echo -e "\e[31mFAIL\e[0m $t (exit code $ret)"
+        pass=0
+    fi
+
+    if ! diff $t.out test.log > /dev/null 2>&1; then
+        echo -e "\e[31mFAIL\e[0m $t (output difference)"
+        diff -u $t.out test.log
+        pass=0
+    fi
+
+    if [ $pass == 1 ]; then
+        echo -e "\e[32mPASS\e[0m $t"
+    fi
+
+done
diff --git a/tests/multiboot/start.S b/tests/multiboot/start.S
new file mode 100644
index 0000000..7d33959
--- /dev/null
+++ b/tests/multiboot/start.S
@@ -0,0 +1,51 @@ 
+/*
+ * Copyright (c) 2013 Kevin Wolf <kwolf@redhat.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+.section multiboot
+
+#define MB_MAGIC 0x1badb002
+#define MB_FLAGS 0x0
+#define MB_CHECKSUM -(MB_MAGIC + MB_FLAGS)
+
+.align  4
+.int    MB_MAGIC
+.int    MB_FLAGS
+.int    MB_CHECKSUM
+
+.section .text
+.global _start
+_start:
+    mov     $stack, %esp
+    push    %ebx
+    push    %eax
+    call    test_main
+
+    /* Test device exit */
+    outl    %eax, $0xf4
+
+    cli
+    hlt
+    jmp .
+
+.section bss
+.space 8192
+stack: