efi-boot-shim/fallback.c
Peter Jones 6edc6ec0a3 [fallback] For HD() device paths, use just the media node and later.
UEFI 2.x section 3.1.2 provides for "short-form device path", where the
first element specified is a "hard drive media device path", so that you
can move a disk around on different buses without invalidating your
device path.  Fallback has not been using this option, though in most
cases efibootmgr has.

Note that we still keep the full device path, because LoadImage()
isn't necessarily the layer where HD() works - one some systems BDS is
responsible for resolving the full path and passes that to LoadImage()
instead.  So we have to do LoadImage() with the full path.
2014-01-31 10:30:36 -05:00

734 lines
17 KiB
C

/*
* Copyright 2012-2013 Red Hat, Inc.
* All rights reserved.
*
* See "COPYING" for license terms.
*
* Author(s): Peter Jones <pjones@redhat.com>
*/
#include <efi.h>
#include <efilib.h>
#include "ucs2.h"
EFI_LOADED_IMAGE *this_image = NULL;
static EFI_STATUS
FindSubDevicePath(EFI_DEVICE_PATH *In, UINT8 Type, UINT8 SubType,
EFI_DEVICE_PATH **Out)
{
EFI_DEVICE_PATH *dp = In;
if (!In || !Out)
return EFI_INVALID_PARAMETER;
for (dp = In; !IsDevicePathEnd(dp); dp = NextDevicePathNode(dp)) {
if (DevicePathType(dp) == Type &&
DevicePathSubType(dp) == SubType) {
*Out = DuplicateDevicePath(dp);
if (!*Out)
return EFI_OUT_OF_RESOURCES;
return EFI_SUCCESS;
}
}
*Out = NULL;
return EFI_NOT_FOUND;
}
static EFI_STATUS
get_file_size(EFI_FILE_HANDLE fh, UINTN *retsize)
{
EFI_STATUS rc;
void *buffer = NULL;
UINTN bs = 0;
EFI_GUID finfo = EFI_FILE_INFO_ID;
/* The API here is "Call it once with bs=0, it fills in bs,
* then allocate a buffer and ask again to get it filled. */
rc = uefi_call_wrapper(fh->GetInfo, 4, fh, &finfo, &bs, NULL);
if (rc == EFI_BUFFER_TOO_SMALL) {
buffer = AllocateZeroPool(bs);
if (!buffer) {
Print(L"Could not allocate memory\n");
return EFI_OUT_OF_RESOURCES;
}
rc = uefi_call_wrapper(fh->GetInfo, 4, fh, &finfo,
&bs, buffer);
}
/* This checks *either* the error from the first GetInfo, if it isn't
* the EFI_BUFFER_TOO_SMALL we're expecting, or the second GetInfo call
* in *any* case. */
if (EFI_ERROR(rc)) {
Print(L"Could not get file info: %d\n", rc);
if (buffer)
FreePool(buffer);
return rc;
}
EFI_FILE_INFO *fi = buffer;
*retsize = fi->FileSize;
FreePool(buffer);
return EFI_SUCCESS;
}
EFI_STATUS
read_file(EFI_FILE_HANDLE fh, CHAR16 *fullpath, CHAR16 **buffer, UINT64 *bs)
{
EFI_FILE_HANDLE fh2;
EFI_STATUS rc = uefi_call_wrapper(fh->Open, 5, fh, &fh2, fullpath,
EFI_FILE_READ_ONLY, 0);
if (EFI_ERROR(rc)) {
Print(L"Couldn't open \"%s\": %d\n", fullpath, rc);
return rc;
}
UINTN len = 0;
CHAR16 *b = NULL;
rc = get_file_size(fh2, &len);
if (EFI_ERROR(rc)) {
uefi_call_wrapper(fh2->Close, 1, fh2);
return rc;
}
b = AllocateZeroPool(len + 2);
if (!buffer) {
Print(L"Could not allocate memory\n");
uefi_call_wrapper(fh2->Close, 1, fh2);
return EFI_OUT_OF_RESOURCES;
}
rc = uefi_call_wrapper(fh->Read, 3, fh, &len, b);
if (EFI_ERROR(rc)) {
FreePool(buffer);
uefi_call_wrapper(fh2->Close, 1, fh2);
Print(L"Could not read file: %d\n", rc);
return rc;
}
*buffer = b;
*bs = len;
uefi_call_wrapper(fh2->Close, 1, fh2);
return EFI_SUCCESS;
}
EFI_STATUS
make_full_path(CHAR16 *dirname, CHAR16 *filename, CHAR16 **out, UINT64 *outlen)
{
UINT64 len;
len = StrLen(L"\\EFI\\") + StrLen(dirname)
+ StrLen(L"\\") + StrLen(filename)
+ 2;
CHAR16 *fullpath = AllocateZeroPool(len*sizeof(CHAR16));
if (!fullpath) {
Print(L"Could not allocate memory\n");
return EFI_OUT_OF_RESOURCES;
}
StrCat(fullpath, L"\\EFI\\");
StrCat(fullpath, dirname);
StrCat(fullpath, L"\\");
StrCat(fullpath, filename);
*out = fullpath;
*outlen = len;
return EFI_SUCCESS;
}
CHAR16 *bootorder = NULL;
int nbootorder = 0;
EFI_DEVICE_PATH *first_new_option = NULL;
VOID *first_new_option_args = NULL;
UINTN first_new_option_size = 0;
EFI_STATUS
add_boot_option(EFI_DEVICE_PATH *hddp, EFI_DEVICE_PATH *fulldp,
CHAR16 *filename, CHAR16 *label, CHAR16 *arguments)
{
static int i = 0;
CHAR16 varname[] = L"Boot0000";
CHAR16 hexmap[] = L"0123456789ABCDEF";
EFI_GUID global = EFI_GLOBAL_VARIABLE;
EFI_STATUS rc;
for(; i <= 0xffff; i++) {
varname[4] = hexmap[(i & 0xf000) >> 12];
varname[5] = hexmap[(i & 0x0f00) >> 8];
varname[6] = hexmap[(i & 0x00f0) >> 4];
varname[7] = hexmap[(i & 0x000f) >> 0];
void *var = LibGetVariable(varname, &global);
if (!var) {
int size = sizeof(UINT32) + sizeof (UINT16) +
StrLen(label)*2 + 2 + DevicePathSize(hddp) +
StrLen(arguments) * 2;
CHAR8 *data = AllocateZeroPool(size);
CHAR8 *cursor = data;
*(UINT32 *)cursor = LOAD_OPTION_ACTIVE;
cursor += sizeof (UINT32);
*(UINT16 *)cursor = DevicePathSize(hddp);
cursor += sizeof (UINT16);
StrCpy((CHAR16 *)cursor, label);
cursor += StrLen(label)*2 + 2;
CopyMem(cursor, hddp, DevicePathSize(hddp));
cursor += DevicePathSize(hddp);
StrCpy((CHAR16 *)cursor, arguments);
Print(L"Creating boot entry \"%s\" with label \"%s\" "
L"for file \"%s\"\n",
varname, label, filename);
if (!first_new_option) {
first_new_option = DuplicateDevicePath(fulldp);
first_new_option_args = arguments;
first_new_option_size = StrLen(arguments) * sizeof (CHAR16);
}
rc = uefi_call_wrapper(RT->SetVariable, 5, varname,
&global, EFI_VARIABLE_NON_VOLATILE |
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
size, data);
FreePool(data);
if (EFI_ERROR(rc)) {
Print(L"Could not create variable: %d\n", rc);
return rc;
}
CHAR16 *newbootorder = AllocateZeroPool(sizeof (CHAR16)
* (nbootorder + 1));
if (!newbootorder)
return EFI_OUT_OF_RESOURCES;
int j = 0;
if (nbootorder) {
for (j = 0; j < nbootorder; j++)
newbootorder[j] = bootorder[j];
FreePool(bootorder);
}
newbootorder[j] = i & 0xffff;
bootorder = newbootorder;
nbootorder += 1;
#ifdef DEBUG_FALLBACK
Print(L"nbootorder: %d\nBootOrder: ", nbootorder);
for (j = 0 ; j < nbootorder ; j++)
Print(L"%04x ", bootorder[j]);
Print(L"\n");
#endif
return EFI_SUCCESS;
}
}
return EFI_OUT_OF_RESOURCES;
}
EFI_STATUS
update_boot_order(void)
{
CHAR16 *oldbootorder;
UINTN size;
EFI_GUID global = EFI_GLOBAL_VARIABLE;
CHAR16 *newbootorder = NULL;
oldbootorder = LibGetVariableAndSize(L"BootOrder", &global, &size);
if (oldbootorder) {
int n = size / sizeof (CHAR16) + nbootorder;
newbootorder = AllocateZeroPool(n * sizeof (CHAR16));
if (!newbootorder)
return EFI_OUT_OF_RESOURCES;
CopyMem(newbootorder, bootorder, nbootorder * sizeof (CHAR16));
CopyMem(newbootorder + nbootorder, oldbootorder, size);
size = n * sizeof (CHAR16);
} else {
size = nbootorder * sizeof(CHAR16);
newbootorder = AllocateZeroPool(size);
if (!newbootorder)
return EFI_OUT_OF_RESOURCES;
CopyMem(newbootorder, bootorder, size);
}
#ifdef DEBUG_FALLBACK
Print(L"nbootorder: %d\nBootOrder: ", size / sizeof (CHAR16));
int j;
for (j = 0 ; j < size / sizeof (CHAR16); j++)
Print(L"%04x ", newbootorder[j]);
Print(L"\n");
#endif
if (oldbootorder) {
LibDeleteVariable(L"BootOrder", &global);
FreePool(oldbootorder);
}
EFI_STATUS rc;
rc = uefi_call_wrapper(RT->SetVariable, 5, L"BootOrder", &global,
EFI_VARIABLE_NON_VOLATILE |
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
size, newbootorder);
FreePool(newbootorder);
return rc;
}
EFI_STATUS
add_to_boot_list(EFI_FILE_HANDLE fh, CHAR16 *dirname, CHAR16 *filename, CHAR16 *label, CHAR16 *arguments)
{
CHAR16 *fullpath = NULL;
UINT64 pathlen = 0;
EFI_STATUS rc = EFI_SUCCESS;
rc = make_full_path(dirname, filename, &fullpath, &pathlen);
if (EFI_ERROR(rc))
return rc;
EFI_DEVICE_PATH *dph = NULL;
EFI_DEVICE_PATH *file = NULL;
EFI_DEVICE_PATH *full_device_path = NULL;
EFI_DEVICE_PATH *dp = NULL;
dph = DevicePathFromHandle(this_image->DeviceHandle);
if (!dph) {
rc = EFI_OUT_OF_RESOURCES;
goto err;
}
file = FileDevicePath(fh, fullpath);
if (!file) {
rc = EFI_OUT_OF_RESOURCES;
goto err;
}
full_device_path = AppendDevicePath(dph, file);
if (!full_device_path) {
rc = EFI_OUT_OF_RESOURCES;
goto err;
}
rc = FindSubDevicePath(full_device_path,
MEDIA_DEVICE_PATH, MEDIA_HARDDRIVE_DP, &dp);
if (EFI_ERROR(rc)) {
if (rc == EFI_NOT_FOUND) {
dp = full_device_path;
} else {
rc = EFI_OUT_OF_RESOURCES;
goto err;
}
}
#ifdef DEBUG_FALLBACK
{
UINTN s = DevicePathSize(dp);
int i;
UINT8 *dpv = (void *)dp;
for (i = 0; i < s; i++) {
if (i > 0 && i % 16 == 0)
Print(L"\n");
Print(L"%02x ", dpv[i]);
}
Print(L"\n");
CHAR16 *dps = DevicePathToStr(dp);
Print(L"device path: \"%s\"\n", dps);
}
#endif
add_boot_option(dp, full_device_path, fullpath, label, arguments);
err:
if (file)
FreePool(file);
if (full_device_path)
FreePool(full_device_path);
if (dp)
FreePool(dp);
if (fullpath)
FreePool(fullpath);
return rc;
}
EFI_STATUS
populate_stanza(EFI_FILE_HANDLE fh, CHAR16 *dirname, CHAR16 *filename, CHAR16 *csv)
{
#ifdef DEBUG_FALLBACK
Print(L"CSV data: \"%s\"\n", csv);
#endif
CHAR16 *file = csv;
UINTN comma0 = StrCSpn(csv, L",");
if (comma0 == 0)
return EFI_INVALID_PARAMETER;
file[comma0] = L'\0';
#ifdef DEBUG_FALLBACK
Print(L"filename: \"%s\"\n", file);
#endif
CHAR16 *label = csv + comma0 + 1;
UINTN comma1 = StrCSpn(label, L",");
if (comma1 == 0)
return EFI_INVALID_PARAMETER;
label[comma1] = L'\0';
#ifdef DEBUG_FALLBACK
Print(L"label: \"%s\"\n", label);
#endif
CHAR16 *arguments = csv + comma0 +1 + comma1 +1;
UINTN comma2 = StrCSpn(arguments, L",");
arguments[comma2] = L'\0';
/* This one is optional, so don't check if comma2 is 0 */
#ifdef DEBUG_FALLBACK
Print(L"arguments: \"%s\"\n", arguments);
#endif
add_to_boot_list(fh, dirname, file, label, arguments);
return EFI_SUCCESS;
}
EFI_STATUS
try_boot_csv(EFI_FILE_HANDLE fh, CHAR16 *dirname, CHAR16 *filename)
{
CHAR16 *fullpath = NULL;
UINT64 pathlen = 0;
EFI_STATUS rc;
rc = make_full_path(dirname, filename, &fullpath, &pathlen);
if (EFI_ERROR(rc))
return rc;
#ifdef DEBUG_FALLBACK
Print(L"Found file \"%s\"\n", fullpath);
#endif
CHAR16 *buffer;
UINT64 bs;
rc = read_file(fh, fullpath, &buffer, &bs);
if (EFI_ERROR(rc)) {
Print(L"Could not read file \"%s\": %d\n", fullpath, rc);
FreePool(fullpath);
return rc;
}
FreePool(fullpath);
#ifdef DEBUG_FALLBACK
Print(L"File looks like:\n%s\n", buffer);
#endif
CHAR16 *start = buffer;
/* The file may or may not start with the Unicode byte order marker.
* Sadness ensues. Since UEFI is defined as LE, I'm going to decree
* that these files must also be LE.
*
* IT IS THUS SO.
*
* But if we find the LE byte order marker, just skip it.
*/
if (*start == 0xfeff)
start++;
while (*start) {
while (*start == L'\r' || *start == L'\n')
start++;
UINTN l = StrCSpn(start, L"\r\n");
if (l == 0) {
if (start[l] == L'\0')
break;
start++;
continue;
}
CHAR16 c = start[l];
start[l] = L'\0';
populate_stanza(fh, dirname, filename, start);
start[l] = c;
start += l;
}
FreePool(buffer);
return EFI_SUCCESS;
}
EFI_STATUS
find_boot_csv(EFI_FILE_HANDLE fh, CHAR16 *dirname)
{
EFI_STATUS rc;
void *buffer = NULL;
UINTN bs = 0;
EFI_GUID finfo = EFI_FILE_INFO_ID;
/* The API here is "Call it once with bs=0, it fills in bs,
* then allocate a buffer and ask again to get it filled. */
rc = uefi_call_wrapper(fh->GetInfo, 4, fh, &finfo, &bs, NULL);
if (rc == EFI_BUFFER_TOO_SMALL) {
buffer = AllocateZeroPool(bs);
if (!buffer) {
Print(L"Could not allocate memory\n");
return EFI_OUT_OF_RESOURCES;
}
rc = uefi_call_wrapper(fh->GetInfo, 4, fh, &finfo,
&bs, buffer);
}
/* This checks *either* the error from the first GetInfo, if it isn't
* the EFI_BUFFER_TOO_SMALL we're expecting, or the second GetInfo call
* in *any* case. */
if (EFI_ERROR(rc)) {
Print(L"Could not get info for \"%s\": %d\n", dirname, rc);
if (buffer)
FreePool(buffer);
return rc;
}
EFI_FILE_INFO *fi = buffer;
if (!(fi->Attribute & EFI_FILE_DIRECTORY)) {
FreePool(buffer);
return EFI_SUCCESS;
}
FreePool(buffer);
buffer = NULL;
bs = 0;
do {
bs = 0;
rc = uefi_call_wrapper(fh->Read, 3, fh, &bs, NULL);
if (EFI_ERROR(rc) && rc != EFI_BUFFER_TOO_SMALL) {
Print(L"Could not read \\EFI\\%s\\: %d\n", dirname, rc);
if (buffer)
FreePool(buffer);
return rc;
}
buffer = AllocateZeroPool(bs);
if (!buffer) {
Print(L"Could not allocate memory\n");
return EFI_OUT_OF_RESOURCES;
}
rc = uefi_call_wrapper(fh->Read, 3, fh, &bs, buffer);
if (EFI_ERROR(rc)) {
Print(L"Could not read \\EFI\\%s\\: %d\n", dirname, rc);
FreePool(buffer);
return rc;
}
if (bs == 0)
break;
fi = buffer;
if (!StrCaseCmp(fi->FileName, L"boot.csv")) {
EFI_FILE_HANDLE fh2;
rc = uefi_call_wrapper(fh->Open, 5, fh, &fh2,
fi->FileName,
EFI_FILE_READ_ONLY, 0);
if (EFI_ERROR(rc) || fh2 == NULL) {
Print(L"Couldn't open \\EFI\\%s\\%s: %d\n",
dirname, fi->FileName, rc);
FreePool(buffer);
buffer = NULL;
continue;
}
rc = try_boot_csv(fh2, dirname, fi->FileName);
uefi_call_wrapper(fh2->Close, 1, fh2);
}
FreePool(buffer);
buffer = NULL;
} while (bs != 0);
rc = EFI_SUCCESS;
return rc;
}
EFI_STATUS
find_boot_options(EFI_HANDLE device)
{
EFI_STATUS rc = EFI_SUCCESS;
EFI_FILE_IO_INTERFACE *fio = NULL;
rc = uefi_call_wrapper(BS->HandleProtocol, 3, device,
&FileSystemProtocol, (void **)&fio);
if (EFI_ERROR(rc)) {
Print(L"Couldn't find file system: %d\n", rc);
return rc;
}
/* EFI_FILE_HANDLE is a pointer to an EFI_FILE, and I have
* *no idea* what frees the memory allocated here. Hopefully
* Close() does. */
EFI_FILE_HANDLE fh = NULL;
rc = uefi_call_wrapper(fio->OpenVolume, 2, fio, &fh);
if (EFI_ERROR(rc) || fh == NULL) {
Print(L"Couldn't open file system: %d\n", rc);
return rc;
}
EFI_FILE_HANDLE fh2 = NULL;
rc = uefi_call_wrapper(fh->Open, 5, fh, &fh2, L"EFI",
EFI_FILE_READ_ONLY, 0);
if (EFI_ERROR(rc) || fh2 == NULL) {
Print(L"Couldn't open EFI: %d\n", rc);
uefi_call_wrapper(fh->Close, 1, fh);
return rc;
}
rc = uefi_call_wrapper(fh2->SetPosition, 2, fh2, 0);
if (EFI_ERROR(rc)) {
Print(L"Couldn't set file position: %d\n", rc);
uefi_call_wrapper(fh2->Close, 1, fh2);
uefi_call_wrapper(fh->Close, 1, fh);
return rc;
}
void *buffer;
UINTN bs;
do {
bs = 0;
rc = uefi_call_wrapper(fh2->Read, 3, fh2, &bs, NULL);
if (rc == EFI_BUFFER_TOO_SMALL ||
(rc == EFI_SUCCESS && bs != 0)) {
buffer = AllocateZeroPool(bs);
if (!buffer) {
Print(L"Could not allocate memory\n");
/* sure, this might work, why not? */
uefi_call_wrapper(fh2->Close, 1, fh2);
uefi_call_wrapper(fh->Close, 1, fh);
return EFI_OUT_OF_RESOURCES;
}
rc = uefi_call_wrapper(fh2->Read, 3, fh2, &bs, buffer);
}
if (bs == 0)
break;
if (EFI_ERROR(rc)) {
Print(L"Could not read \\EFI\\: %d\n", rc);
if (buffer) {
FreePool(buffer);
buffer = NULL;
}
uefi_call_wrapper(fh2->Close, 1, fh2);
uefi_call_wrapper(fh->Close, 1, fh);
return rc;
}
EFI_FILE_INFO *fi = buffer;
if (!(fi->Attribute & EFI_FILE_DIRECTORY)) {
FreePool(buffer);
buffer = NULL;
continue;
}
if (!StrCmp(fi->FileName, L".") ||
!StrCmp(fi->FileName, L"..") ||
!StrCaseCmp(fi->FileName, L"BOOT")) {
FreePool(buffer);
buffer = NULL;
continue;
}
#ifdef DEBUG_FALLBACK
Print(L"Found directory named \"%s\"\n", fi->FileName);
#endif
EFI_FILE_HANDLE fh3;
rc = uefi_call_wrapper(fh->Open, 5, fh2, &fh3, fi->FileName,
EFI_FILE_READ_ONLY, 0);
if (EFI_ERROR(rc)) {
Print(L"%d Couldn't open %s: %d\n", __LINE__, fi->FileName, rc);
FreePool(buffer);
buffer = NULL;
continue;
}
rc = find_boot_csv(fh3, fi->FileName);
FreePool(buffer);
buffer = NULL;
if (rc == EFI_OUT_OF_RESOURCES)
break;
} while (1);
if (rc == EFI_SUCCESS && nbootorder > 0)
rc = update_boot_order();
uefi_call_wrapper(fh2->Close, 1, fh2);
uefi_call_wrapper(fh->Close, 1, fh);
return rc;
}
static EFI_STATUS
try_start_first_option(EFI_HANDLE parent_image_handle)
{
EFI_STATUS rc;
EFI_HANDLE image_handle;
if (!first_new_option) {
return EFI_SUCCESS;
}
rc = uefi_call_wrapper(BS->LoadImage, 6, 0, parent_image_handle,
first_new_option, NULL, 0,
&image_handle);
if (EFI_ERROR(rc)) {
CHAR16 *dps = DevicePathToStr(first_new_option);
UINTN s = DevicePathSize(first_new_option);
int i;
UINT8 *dpv = (void *)first_new_option;
Print(L"LoadImage failed: %d\nDevice path: \"%s\"\n", rc, dps);
for (i = 0; i < s; i++) {
if (i > 0 && i % 16 == 0)
Print(L"\n");
Print(L"%02x ", dpv[i]);
}
Print(L"\n");
uefi_call_wrapper(BS->Stall, 1, 500000000);
return rc;
}
EFI_LOADED_IMAGE *image;
rc = uefi_call_wrapper(BS->HandleProtocol, 3, image_handle, &LoadedImageProtocol, (void *)&image);
if (!EFI_ERROR(rc)) {
image->LoadOptions = first_new_option_args;
image->LoadOptionsSize = first_new_option_size;
}
rc = uefi_call_wrapper(BS->StartImage, 3, image_handle, NULL, NULL);
if (EFI_ERROR(rc)) {
Print(L"StartImage failed: %d\n", rc);
uefi_call_wrapper(BS->Stall, 1, 500000000);
}
return rc;
}
EFI_STATUS
efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *systab)
{
EFI_STATUS rc;
InitializeLib(image, systab);
rc = uefi_call_wrapper(BS->HandleProtocol, 3, image, &LoadedImageProtocol, (void *)&this_image);
if (EFI_ERROR(rc)) {
Print(L"Error: could not find loaded image: %d\n", rc);
return rc;
}
Print(L"System BootOrder not found. Initializing defaults.\n");
rc = find_boot_options(this_image->DeviceHandle);
if (EFI_ERROR(rc)) {
Print(L"Error: could not find boot options: %d\n", rc);
return rc;
}
try_start_first_option(image);
Print(L"Reset System\n");
uefi_call_wrapper(RT->ResetSystem, 4, EfiResetCold,
EFI_SUCCESS, 0, NULL);
return EFI_SUCCESS;
}