[U-Boot] [PATCH v6 3/7] cmd: efidebug: add devices command
AKASHI Takahiro
takahiro.akashi at linaro.org
Wed Feb 20 07:42:39 UTC 2019
On Wed, Feb 20, 2019 at 07:49:01AM +0100, Heinrich Schuchardt wrote:
> On 2/20/19 3:20 AM, AKASHI Takahiro wrote:
> > On Tue, Feb 19, 2019 at 08:46:52PM +0100, Heinrich Schuchardt wrote:
> >> On 1/24/19 12:04 PM, AKASHI Takahiro wrote:
> >>> "devices" command prints all the uefi variables on the system.
> >>>
> >>> => efi devices
> >>> Scanning disk ahci_scsi.id0lun0...
> >>> Scanning disk ahci_scsi.id1lun0...
> >>> Found 4 disks
> >>> Device Device Path
> >>> ================ ====================
> >>> 000000007ef07ea0 /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)
> >>> 000000007ef00c10 /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/Scsi(0,0)
> >>> 000000007ef00dd0 /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/Scsi(1,0)
> >>> 000000007ef07be0 /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/Scsi(1,0)/HD(1,MBR,0x086246ba,0x800,0x40000)
> >>> 000000007ef07510 /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/Scsi(1,0)/HD(2,MBR,0x086246ba,0x40800,0x3f800)
> >>>
> >>> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> >>> ---
> >>> cmd/efidebug.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++++-
> >>> 1 file changed, 101 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/cmd/efidebug.c b/cmd/efidebug.c
> >>> index d836576cf6e0..8a7f775b117a 100644
> >>> --- a/cmd/efidebug.c
> >>> +++ b/cmd/efidebug.c
> >>> @@ -15,6 +15,102 @@
> >>> #include <search.h>
> >>> #include <linux/ctype.h>
> >>>
> >>> +#define BS systab.boottime
> >>> +
> >>
> >> Please, add Sphinx style descriptions to all functions, their
> >> parameters, and return values.
> >
> > Sure, but please clearify what you mean by "all."
> > Do you expect descriptions for exactly all the functions,
> > even for some helper functions of a few lines of code?
> >
> >> Why do you need this function? Can't you call LocateHandleBuffer() which
> >> takes care of the allocation of the buffer?
> >>
> >>> +static int efi_get_handles_by_proto(efi_guid_t *guid, efi_handle_t **handlesp,
> >>> + int *num)
> >
> > Right. I will use locate_handle_buffer here.
> > But why does UEFI spec define functionally-duplicated functions,
> > LocateHandle() and LocateHandleBuffer()?
> >
> >>> +{
> >>> + efi_handle_t *handles = NULL;
> >>> + efi_uintn_t size = 0;
> >>> + efi_status_t ret;
> >>> +
> >>> + if (guid) {
> >>> + ret = BS->locate_handle(BY_PROTOCOL, guid, NULL, &size,
> >>> + handles);
> >>
> >> This will not work on i386. Please, always use EFI_CALL when invoking a
> >> function which calls EFI_ENTRY().
> >
> > OK, but let me make sure.
> > We don't have to use EFI_CALL() for any of (internal) efi_xxx() functions,
> > say, efi_add_protocol(). Right?
>
> EFI_ENTRY() and EFI_EXIT() change the content of the register to which
> gd is mapped and executes an assert. So only functions starting with
> EFI_ENTRY() should be called via EFI_CALL. Please, do not call other
> functions via EFI_CALL().
Thank you for explanation.
> Please, check that efi_save_gd() is called (e.g. via
> efi_init_obj_list()) before the first EFI_CALL().
I didn't notice that.
Can you please leave some document about this kind of usage
so that future UEFI developers be aware of it.
> To get rid of the systab.boottime dereference it might be preferable to
> change static functions to global once.
Do you mean, for example, we should call efi_open_protocol()
instead of BS->open_protocol()?
I hesitate to agree with you as we should try to call exported *API's*
wherever possible, in particular, in EFI-application-like code, like efidebug.
-Takahiro Akashi
> Best regards
>
> Heinrich
>
> >
> >>> + if (ret == EFI_BUFFER_TOO_SMALL) {
> >>> + handles = calloc(1, size);
> >>> + if (!handles)
> >>> + return -1;
> >>> +
> >>> + ret = BS->locate_handle(BY_PROTOCOL, guid, NULL, &size,
> >>> + handles);
> >>> + }
> >>> + if (ret != EFI_SUCCESS) {
> >>> + free(handles);
> >>
> >> The handles are not allocated by malloc(). Use FreePool() here.
> >
> > Will take care of that along with the change above.
> >
> > -Takahiro Akashi
> >
> >
> >>> + return -1;
> >>> + }
> >>> + } else {
> >>> + ret = BS->locate_handle(ALL_HANDLES, NULL, NULL, &size, NULL);
> >>> + if (ret == EFI_BUFFER_TOO_SMALL) {
> >>> + handles = calloc(1, size);
> >>> + if (!handles)
> >>> + return -1;
> >>> +
> >>> + ret = BS->locate_handle(ALL_HANDLES, NULL, NULL, &size,
> >>> + handles);
> >>> + }
> >>> + if (ret != EFI_SUCCESS) {
> >>> + free(handles);
> >>
> >> Same here.
> >>
> >>> + return -1;
> >>> + }
> >>> + }
> >>> +
> >>> + *handlesp = handles;
> >>> + *num = size / sizeof(efi_handle_t);
> >>> +
> >>> + return 0;
> >>> +}
> >>> +
> >>> +static int efi_get_device_handle_info(efi_handle_t handle, u16 **dev_path_text)
> >>> +{
> >>> + struct efi_device_path *dp;
> >>> + efi_status_t ret;
> >>> +
> >>> + ret = BS->open_protocol(handle, &efi_guid_device_path,
> >>> + (void **)&dp, NULL /* FIXME */, NULL,
> >>> + EFI_OPEN_PROTOCOL_GET_PROTOCOL);
> >>> + if (ret == EFI_SUCCESS) {
> >>> + *dev_path_text = efi_dp_str(dp);
> >>> + return 0;
> >>> + } else {
> >>> + return -1;
> >>> + }
> >>> +}
> >>> +
> >>> +#define EFI_HANDLE_WIDTH ((int)sizeof(efi_handle_t) * 2)
> >>> +
> >>> +static const char spc[] = " ";
> >>> +static const char sep[] = "================";
> >>> +
> >>> +static int do_efi_show_devices(cmd_tbl_t *cmdtp, int flag,
> >>> + int argc, char * const argv[])
> >>> +{
> >>> + efi_handle_t *handles;
> >>> + u16 *dev_path_text;
> >>> + int num, i;
> >>> +
> >>> + handles = NULL;
> >>> + num = 0;
> >>> + if (efi_get_handles_by_proto(NULL, &handles, &num))
> >>> + return CMD_RET_FAILURE;
> >>> +
> >>> + if (!num)
> >>> + return CMD_RET_SUCCESS;
> >>> +
> >>> + printf("Device%.*s Device Path\n", EFI_HANDLE_WIDTH - 6, spc);
> >>> + printf("%.*s ====================\n", EFI_HANDLE_WIDTH, sep);
> >>> + for (i = 0; i < num; i++) {
> >>> + if (!efi_get_device_handle_info(handles[i], &dev_path_text)) {
> >>> + printf("%p %ls\n", handles[i], dev_path_text);
> >>> + efi_free_pool(dev_path_text);
> >>> + }
> >>> + }
> >>> +
> >>> + free(handles);
> >>
> >> FreePool()!
> >>
> >> Best regards
> >>
> >> Heinrich
> >>
> >>> +
> >>> + return CMD_RET_SUCCESS;
> >>> +}
> >>> +
> >>> static int do_efi_boot_add(cmd_tbl_t *cmdtp, int flag,
> >>> int argc, char * const argv[])
> >>> {
> >>> @@ -406,6 +502,8 @@ static int do_efi_boot_opt(cmd_tbl_t *cmdtp, int flag,
> >>>
> >>> static cmd_tbl_t cmd_efidebug_sub[] = {
> >>> U_BOOT_CMD_MKENT(boot, CONFIG_SYS_MAXARGS, 1, do_efi_boot_opt, "", ""),
> >>> + U_BOOT_CMD_MKENT(devices, CONFIG_SYS_MAXARGS, 1, do_efi_show_devices,
> >>> + "", ""),
> >>> };
> >>>
> >>> /* Interpreter command to configure UEFI environment */
> >>> @@ -451,7 +549,9 @@ static char efidebug_help_text[] =
> >>> " - set UEFI BootNext variable\n"
> >>> "efidebug boot order [<bootid#1> [<bootid#2> [<bootid#3> [...]]]]\n"
> >>> " - set/show UEFI boot order\n"
> >>> - "\n";
> >>> + "\n"
> >>> + "efidebug devices\n"
> >>> + " - show uefi devices\n";
> >>> #endif
> >>>
> >>> U_BOOT_CMD(
> >>>
> >>
> >
>
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