[U-Boot] [PATCH v2 1/3] efi_loader: rework fdt handling in distro boot script
AKASHI Takahiro
takahiro.akashi at linaro.org
Tue Oct 23 02:08:00 UTC 2018
On Mon, Oct 22, 2018 at 08:42:32AM +0100, Alexander Graf wrote:
>
>
> On 22.10.18 08:22, AKASHI Takahiro wrote:
> > On Mon, Oct 22, 2018 at 01:40:05PM +0900, AKASHI Takahiro wrote:
> >> The current scenario for default UEFI booting, scan_dev_for_efi, has
> >> several issues:
> >> * load dtb dynamically even if its loacation (device) is not the same
> >> as BOOTEFI_NAME binary's, (reported by Alex)
> >> * invoke 'bootmgr' only if BOOTEFI_NAME binary does exit even though
> >> 'bootmgr' can and should work independently whether or not the binary
> >> exist,
> >> * in addition, invoke 'bootmgr' with dynamically-loaded dtb.
> >> This behavior is not expected. (reported by Alex)
> >> * always assume that a 'fdtfile' variable is defined,
> >> ("test -e ${devtype} ${devnum}:${distro_bootpart} "${prefix}${efi_fdtfile}"
> >> always returns true even if fdtfile is NULL with prefix=="/".)
> >> * redundantly check for 'fdt_addr_r' in boot_efi_binary
> >>
> >> In this patch, all the issues above are sorted out.
> >> Please note that the default behavior can be customized with:
> >> fdtfile: a dtb file name
> >> efi_dtb_prefixes: a list of paths for searching for a dtb file
> >>
> >> (this feature does work even without this patch.)
> >>
> >> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> >> ---
> >> include/config_distro_bootcmd.h | 38 +++++++++++++++++----------------
> >> 1 file changed, 20 insertions(+), 18 deletions(-)
> >>
> >> diff --git a/include/config_distro_bootcmd.h b/include/config_distro_bootcmd.h
> >> index 373fee78a999..256698309eb9 100644
> >> --- a/include/config_distro_bootcmd.h
> >> +++ b/include/config_distro_bootcmd.h
> >> @@ -115,7 +115,7 @@
> >> */
> >> #define BOOTENV_EFI_SET_FDTFILE_FALLBACK \
> >> "if test -z \"${fdtfile}\" -a -n \"${soc}\"; then " \
> >> - "setenv efi_fdtfile ${soc}-${board}${boardver}.dtb; " \
> >> + "efi_fdtfile=${soc}-${board}${boardver}.dtb; " \
> >> "fi; "
> >> #else
> >> #define BOOTENV_EFI_SET_FDTFILE_FALLBACK
> >> @@ -124,26 +124,20 @@
> >>
> >> #define BOOTENV_SHARED_EFI \
> >> "boot_efi_binary=" \
> >> - "if fdt addr ${fdt_addr_r}; then " \
> >> - "bootefi bootmgr ${fdt_addr_r};" \
> >> - "else " \
> >> - "bootefi bootmgr ${fdtcontroladdr};" \
> >> - "fi;" \
> >> "load ${devtype} ${devnum}:${distro_bootpart} " \
> >> "${kernel_addr_r} efi/boot/"BOOTEFI_NAME"; " \
> >> - "if fdt addr ${fdt_addr_r}; then " \
> >> - "bootefi ${kernel_addr_r} ${fdt_addr_r};" \
> >> - "else " \
> >> - "bootefi ${kernel_addr_r} ${fdtcontroladdr};" \
> >> - "fi\0" \
> >> + "bootefi ${kernel_addr_r} ${efi_fdt_addr};\0" \
> >> \
> >> "load_efi_dtb=" \
> >> - "load ${devtype} ${devnum}:${distro_bootpart} " \
> >> - "${fdt_addr_r} ${prefix}${efi_fdtfile}\0" \
> >> + "load ${devtype} ${devnum}:${distro_bootpart} " \
> >> + "${fdt_addr_r} ${prefix}${efi_fdtfile}; " \
> >> + "if fdt addr ${fdt_addr_r}; then " \
> >> + "efi_fdt_addr=${fdt_addr_r}; " \
> >> + "fi;\0" \
> >> \
> >> "efi_dtb_prefixes=/ /dtb/ /dtb/current/\0" \
> >> - "scan_dev_for_efi=" \
> >> - "setenv efi_fdtfile ${fdtfile}; " \
> >> + "set_efi_fdt_addr=" \
> >> + "efi_fdtfile=${fdtfile}; " \
> >> BOOTENV_EFI_SET_FDTFILE_FALLBACK \
> >> "for prefix in ${efi_dtb_prefixes}; do " \
> >> "if test -e ${devtype} " \
> >> @@ -151,19 +145,26 @@
> >> "${prefix}${efi_fdtfile}; then " \
> >> "run load_efi_dtb; " \
> >> "fi;" \
> >> - "done;" \
> >> + "done;\0" \
> >> + \
> >> + "scan_dev_for_efi=" \
> >> "if test -e ${devtype} ${devnum}:${distro_bootpart} " \
> >> "efi/boot/"BOOTEFI_NAME"; then " \
> >> "echo Found EFI removable media binary " \
> >> "efi/boot/"BOOTEFI_NAME"; " \
> >> + "efi_fdt_addr=${fdtcontroladdr}; " \
> >> + "if test -n \"${fdtfile}\"; then " \
> >> + "run set_efi_fdt_addr; " \
> >> + "fi; " \
> >> "run boot_efi_binary; " \
> >> "echo EFI LOAD FAILED: continuing...; " \
> >> - "fi; " \
> >> - "setenv efi_fdtfile\0"
> >> + "fi;\0"
> >> #define SCAN_DEV_FOR_EFI "run scan_dev_for_efi;"
> >> +#define BOOT_EFI_BOOT_MANAGER "bootefi bootmgr;"
> >> #else
> >> #define BOOTENV_SHARED_EFI
> >> #define SCAN_DEV_FOR_EFI
> >> +#define BOOT_EFI_BOOT_MANAGER
> >> #endif
> >>
> >> #ifdef CONFIG_SATA
> >> @@ -409,6 +410,7 @@
> >> BOOT_TARGET_DEVICES(BOOTENV_DEV) \
> >> \
> >> "distro_bootcmd=" BOOTENV_SET_SCSI_NEED_INIT \
> >> + BOOT_EFI_BOOT_MANAGER \
> >
> > The last-minute change may have introduced a problem.
> > By moving "bootmgr" from scan_dev_for_efi" to here,
> > grub fails to start a grub.cfg menu, saying
> > "error: no such device: /.disk/info."
> >
> > Do you have any ideas?
>
> I would guess that bootmgr doesn't set the loaded image target correctly
> and before it just happened to work because there was a load command
> before the bootmgr command?
The root cause was that efi_init_obj_list(), particularly efi_disk_register(),
is executed only once.
In my case, efi bootmgr is called before "usb start" in scan_dev_for_efi,
and any USB devices will not be added to efi object list forever.
Therefore, later on, grub itself can start but cannot detect/access its own
boot device (USB mass storage) via efi interface.
I think we can fix this problem in several ways:
1. run all 'device-scanning' commands, like "usb start" and "scsi scan,"
before calling bootmgr in distro_bootcmd,
2. modify efi_obj_init_list() to check and register newly-detected devices,
3. add a device to efi object list dynamically whenever a 'device-scanning'
command detects one,
4. search and check for a device on-the-fly with each efi device path
(or handle?) specified in efi interface
What do you think?
-Takahiro Akashi
> https://github.com/u-boot/u-boot/blob/master/cmd/fs.c#L26
>
>
> Alex
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