[U-Boot] [PATCH v3 1/1] efi_loader: rework fdt handling in distro boot script

AKASHI Takahiro
2018-12-03T02:22:40Z

On Sun, Dec 02, 2018 at 11:58:45PM +0100, Alexander Graf wrote:
>
>
> On 27.11.18 01:33, 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@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"
>
> This drops the bit that unsets the variable. So after the script, your
> env will be different from before the script.

Yeah, but

> Please run
>
> U-Boot# printenv
> U-Boot# boot (w/o any efi payload to boot)
> U-Boot# printenv
>
> Then diff the two environments. They should be identical.

Are you sure? When I try this on unmodified v2018.11,
I also see some difference:

18a19
> devnum=0
37a39
> scsi_need_init=false
44c46
< Environment size: 3614/65532 bytes
---
> Environment size: 3644/65532 bytes

It seems that 'devnum' and 'scsi_need_init' come from 'bootcmd_scsi0.'
Can you clarify your point a bit more, please?

Thanks,
-Takahiro Akashi

>
>
> Alex