[PATCHv4 2/6] boot_fdt_add_mem_rsv_regions: free old dtb reservations

[Simon Glass]

Hi Randolph,

On Wed, 22 Apr 2026 at 10:14, Randolph Sapp <rs at ti.com> wrote:
>
> On Tue Apr 21, 2026 at 3:40 PM CDT, Simon Glass wrote:
> > Hi Randolph,
> >
> > On 2026-04-20T19:25:18, Randolph Sapp <rs at ti.com> wrote:
> >> boot_fdt_add_mem_rsv_regions: free old dtb reservations
> >>
> >> Add a free flag and an initial call to free allocations covered by the
> >> global FDT. This assumes that all calls to boot_fdt_add_mem_rsv_regions
> >> occur before the transition to the new device tree, thus we can access
> >> the currently active device tree through the global data pointer.
> >>
> >> This allows us to clearly indicate to the user when a device tree
> >> reservation fails. How we handle this can still use some improvement.
> >> Right now we'll keep the default behavior and try to boot anyway.
> >>
> >> This functionality was broken in:
> >> 5a6aa7d ("boot: fdt: Handle already reserved memory in boot_fdt_reserve_region()")
> >>
> >> Signed-off-by: Randolph Sapp <rs at ti.com>
> >>
> >> arch/mips/lib/bootm.c |  2 +-
> >>  boot/bootm.c          |  2 +-
> >>  boot/bootm_os.c       |  2 +-
> >>  boot/image-board.c    |  2 +-
> >>  boot/image-fdt.c      | 57 +++++++++++++++++++++++++++++++++++----------------
> >>  include/image.h       |  2 +-
> >>  lib/lmb.c             |  2 +-
> >>  7 files changed, 45 insertions(+), 24 deletions(-)
> >
> >> diff --git a/boot/image-fdt.c b/boot/image-fdt.c
> >> @@ -69,35 +69,51 @@ static const struct legacy_img_hdr *image_get_fdt(ulong fdt_addr)
> >> +static void boot_fdt_reserve_region(u64 addr, u64 size, u32 flags, bool free)
> >>  {
> >> -     long ret;
> >> +     int ret;
> >
> > nit: perhaps keep this one 'long' since lmb_free() returns long ?
> >
> > Regards,
> > Simon
>
> Ugh, yeah though it should only return 0, -EEXIST, or -1 since that's all
> lmb_add_region_flags returns. I'm not going to ask why that's the case.

Ah yes, I suppose it could be changed to return an int.

Regards,
Simon