Hi, On Tue, 28 Feb 2017 15:16:58 +0100 Patrick Wildt <[email protected]> wrote: > On Tue, Feb 28, 2017 at 10:41:21PM +0900, YASUOKA Masahiko wrote: >> On Mon, 27 Feb 2017 11:10:31 +0100 >> Patrick Wildt <[email protected]> wrote: >> > I'm surprised this didn't come up earlier, but I think the for-loop is a >> > bit wrong. What the code is supposed to be doing is going over each >> > device path node for the loaded image, which is supposed to be the path >> > to the device that efiboot was loaded from, and check for a node that >> > is a medium (as in hard drive, cdrom) and look for a hard drive. >> >> Yes, you are right it's wrong. >> >> > As it turns out, the code would actually skip all device paths that >> > are mediums and instead match on all non-media types. It's surprising >> > to me that this seems to work for people. >> > >> > On Qemu and VMware the first node in the device path is ACPI (2) with >> > subtype (1). Interestingly, the hard drive subtype in the media type >> > has the subtype (1) as well. So that might be a reason it did work. >> >> As far as my test on QEMU and VAIO, the first node is ACPI and subtype >> is 1. >> >> But we had another bug, >> >> 87 if (status == EFI_SUCCESS) { >> 88 for (dp = dp0; !IsDevicePathEnd(dp); >> 89 dp = NextDevicePathNode(dp)) { >> 90 if (DevicePathType(dp) == MEDIA_DEVICE_PATH) >> 91 continue; >> 92 if (DevicePathSubType(dp) == >> MEDIA_HARDDRIVE_DP) { >> 93 bios_bootdev = 0x80; >> 94 efi_bootdp = dp; >> 95 break; >> 96 } >> 97 break; >> 98 } >> 99 } >> >> if we fix the bug at #90, at #94 efi_bootdp will not become the first >> dp node(dp0). Then efi_diskprobe() will fail to reorder hd? properly >> since the function assumes efi_bootdp is the first dp node. >> >> So I'd like to commit the diff below. > > First of all, I've been having a look at supporting CDROMs in efiboot > and saw that FreeBSD has a nice "devpath.c" file which implements a few > good helpers. I've been using efi_devpath_match(), efi_devpath_trim() > and efi_devpath_last_node(). Those have been particularly helpful and > simplify some code. I wonder if it would make sense to pull that one > in instead of writing another completely new implementation of tha same > thing. > >> diff --git a/sys/arch/amd64/stand/efiboot/efiboot.c >> b/sys/arch/amd64/stand/efiboot/efiboot.c >> index 1903862d271..f82ea34f66e 100644 >> --- a/sys/arch/amd64/stand/efiboot/efiboot.c >> +++ b/sys/arch/amd64/stand/efiboot/efiboot.c >> @@ -41,7 +41,8 @@ >> EFI_SYSTEM_TABLE *ST; >> EFI_BOOT_SERVICES *BS; >> EFI_RUNTIME_SERVICES *RS; >> -EFI_HANDLE IH, efi_bootdp = NULL; >> +EFI_HANDLE IH; >> +EFI_DEVICE_PATH *efi_bootdp = NULL; >> EFI_PHYSICAL_ADDRESS heap; >> EFI_LOADED_IMAGE *loadedImage; >> UINTN heapsiz = 1 * 1024 * 1024; >> @@ -51,6 +52,7 @@ static EFI_GUID blkio_guid = BLOCK_IO_PROTOCOL; >> static EFI_GUID devp_guid = DEVICE_PATH_PROTOCOL; >> u_long efi_loadaddr; >> >> +static int efi_device_path_cmp(EFI_DEVICE_PATH *, EFI_DEVICE_PATH *, int); >> static void efi_heap_init(void); >> static void efi_memprobe_internal(void); >> static void efi_video_init(void); >> @@ -87,14 +89,12 @@ efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *systab) >> if (status == EFI_SUCCESS) { >> for (dp = dp0; !IsDevicePathEnd(dp); >> dp = NextDevicePathNode(dp)) { >> - if (DevicePathType(dp) == MEDIA_DEVICE_PATH) >> - continue; >> - if (DevicePathSubType(dp) == MEDIA_HARDDRIVE_DP) { >> + if (DevicePathType(dp) == MEDIA_DEVICE_PATH && >> + DevicePathSubType(dp) == MEDIA_HARDDRIVE_DP) { >> bios_bootdev = 0x80; >> - efi_bootdp = dp; >> + efi_bootdp = dp0; > > This part makes sense to me. > >> break; >> } >> - break; >> } >> } >> >> @@ -166,7 +166,7 @@ efi_diskprobe(void) >> EFI_BLOCK_IO *blkio; >> EFI_BLOCK_IO_MEDIA *media; >> struct diskinfo *di; >> - EFI_DEVICE_PATH *dp, *bp; >> + EFI_DEVICE_PATH *dp; >> >> TAILQ_INIT(&efi_disklist); >> >> @@ -193,23 +193,14 @@ efi_diskprobe(void) >> di = alloc(sizeof(struct diskinfo)); >> efid_init(di, blkio); >> >> - if (efi_bootdp == NULL) >> - goto next; >> - status = EFI_CALL(BS->HandleProtocol, handles[i], &devp_guid, >> - (void **)&dp); >> - if (EFI_ERROR(status)) >> - goto next; >> - bp = efi_bootdp; >> - while (1) { >> - if (IsDevicePathEnd(dp)) { >> + if (efi_bootdp != NULL) { >> + status = EFI_CALL(BS->HandleProtocol, handles[i], >> &devp_guid, >> + (void **)&dp); >> + if (EFI_ERROR(status)) >> + goto next; >> + if (efi_device_path_cmp(efi_bootdp, dp, >> MESSAGING_DEVICE_PATH) >> + == 0) > > This part makes sense to me as well. > >> bootdev = 1; >> - break; >> - } >> - if (memcmp(dp, bp, sizeof(EFI_DEVICE_PATH)) != 0 || >> - memcmp(dp, bp, DevicePathNodeLength(dp)) != 0) >> - break; >> - dp = NextDevicePathNode(dp); >> - bp = NextDevicePathNode(bp); >> } >> next: >> if (bootdev) >> @@ -221,6 +212,35 @@ next: >> free(handles, sz); >> } >> >> +static int >> +efi_device_path_cmp(EFI_DEVICE_PATH *dpa, EFI_DEVICE_PATH *dpb, int dptype) >> +{ >> + int cmp; >> + EFI_DEVICE_PATH *dp, *dpt_a = NULL, *dpt_b = NULL; >> + >> + for (dp = dpa; !IsDevicePathEnd(dp); dp = NextDevicePathNode(dp)) { >> + if (DevicePathType(dp) == dptype) { >> + dpt_a = dp; >> + break; >> + } >> + } >> + for (dp = dpb; !IsDevicePathEnd(dp); dp = NextDevicePathNode(dp)) { >> + if (DevicePathType(dp) == dptype) { >> + dpt_b = dp; >> + break; >> + } >> + } >> + >> + if (dpt_a && dpt_b) { >> + cmp = DevicePathNodeLength(dpt_a) - DevicePathNodeLength(dpt_b); >> + if (cmp) >> + return (cmp); >> + return (memcmp(dpt_a, dpt_b, DevicePathNodeLength(dpt_a))); >> + } >> + >> + return ((uintptr_t)dpt_a - (uintptr_t)dpt_b); >> +} > > I don't like this. Have a look at the FreeBSD implementation, it's > nicer sind you don't have to pass some device path type but instead > it does a full path comparison.
How will you fix by efi_devpath_match()? AFAIK, we need to find the device path of the booted disk. (not the booted parition) So I belive "full path comparison" is not usable. --yasuoka
