diff options
Diffstat (limited to 'futility/vb1_helper.c')
| -rw-r--r-- | futility/vb1_helper.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/futility/vb1_helper.c b/futility/vb1_helper.c index 2a0e87a2..5a8908e6 100644 --- a/futility/vb1_helper.c +++ b/futility/vb1_helper.c @@ -1,4 +1,4 @@ -/* Copyright 2014 The Chromium OS Authors. All rights reserved. +/* Copyright 2014 The ChromiumOS Authors * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ @@ -129,6 +129,18 @@ uint64_t kernel_cmd_line_offset(const struct vb2_kernel_preamble *preamble) CROS_CONFIG_SIZE - CROS_PARAMS_SIZE; } +/* Returns whether the kernel CONFIG_EFI_STUB enabled. */ +static int KernelHasEfiBootStub(const uint8_t *kernel_buf, + uint32_t kernel_size) +{ + if (kernel_size < 2) + return 0; + + /* If the stub is enabled then the kernel data will start with + * the COFF header, which begins with the magic bytes "MZ". */ + return kernel_buf[0] == 'M' && kernel_buf[1] == 'Z'; +} + /* Returns the size of the 32-bit kernel, or negative on error. */ static int KernelSize(uint8_t *kernel_buf, uint32_t kernel_size, @@ -138,7 +150,7 @@ static int KernelSize(uint8_t *kernel_buf, struct linux_kernel_params *lh; /* Except for x86, the kernel is the kernel. */ - if (arch != ARCH_X86) + if (arch != ARCH_X86 || KernelHasEfiBootStub(kernel_buf, kernel_size)) return kernel_size; /* The first part of the x86 vmlinuz is a header, followed by @@ -170,6 +182,13 @@ static int PickApartVmlinuz(uint8_t *kernel_buf, /* Except for x86, the kernel is the kernel. */ switch (arch) { case ARCH_X86: + /* If the kernel has the EFI boot stub enabled, don't + * modify the kernel buffer. */ + if (KernelHasEfiBootStub(kernel_buf, kernel_size)) { + VB2_DEBUG("EFI boot stub detected\n"); + break; + } + /* The first part of the x86 vmlinuz is a header, followed by * a real-mode boot stub. We only want the 32-bit part. */ lh = (struct linux_kernel_params *)kernel_buf; |