[PATCH 3/3] bloblist: Rework bloblist_init and bloblist_maybe_init
Tom Rini
trini at konsulko.com
Sat May 16 17:32:10 CEST 2026
On Fri, May 15, 2026 at 08:10:48PM -0400, Raymond Mao wrote:
> Hi Tom,
>
> On Fri, May 15, 2026 at 12:30 PM Tom Rini <trini at konsulko.com> wrote:
> >
> > On Fri, May 15, 2026 at 11:05:47AM -0400, Raymond Mao wrote:
> > > Hi Tom,
> > >
> > > On Thu, May 14, 2026 at 1:55 PM Tom Rini <trini at konsulko.com> wrote:
> > > >
> > > > With bloblist, we need to both see if one already exists as well as
> > > > create one if it does not. However, the current implementation leads to
> > > > odd cases where we attempt to create a bloblist before this is possible
> > > > and have things be overly complicated when we are given one to work
> > > > with.
> > > >
> > > > This reworks things to instead have a bloblist_exists function, which as
> > > > the name implies checks for an existing bloblist. This is used in
> > > > the case of booting, to see if we have one and in turn if we have a
> > > > device tree there as well as in the bloblist_init function to see if we
> > > > need to do anything.
> > > >
> > > > In practical details, we move the logic from bloblist_init that was
> > > > checking for a bloblist to the new bloblist_exists function and then can
> > > > clarify the logic as it is much easier to state when we know we do not
> > > > have one rather than all the ways we might have one. Then we have the
> > > > locations that set gd->bloblist now also set the GD_FLG_BLOBLIST_READY
> > > > flag.
> > > >
> > > > Signed-off-by: Tom Rini <trini at konsulko.com>
> > > > ---
> > > > common/bloblist.c | 144 +++++++++++++++++++++++----------------------
> > > > common/board_f.c | 4 +-
> > > > include/bloblist.h | 32 +++++-----
> > > > lib/fdtdec.c | 15 ++---
> > > > 4 files changed, 96 insertions(+), 99 deletions(-)
> > > >
> > > > diff --git a/common/bloblist.c b/common/bloblist.c
> > > > index 09afdd1f96b4..51ae9cc50a5f 100644
> > > > --- a/common/bloblist.c
> > > > +++ b/common/bloblist.c
> > > > @@ -448,6 +448,7 @@ int bloblist_new(ulong addr, uint size, uint flags, uint align_log2)
> > > > hdr->align_log2 = align_log2 ? align_log2 : BLOBLIST_BLOB_ALIGN_LOG2;
> > > > hdr->chksum = 0;
> > > > gd->bloblist = hdr;
> > > > + gd->flags |= GD_FLG_BLOBLIST_READY;
> > > >
> > > > return 0;
> > > > }
> > > > @@ -475,6 +476,7 @@ int bloblist_check(ulong addr, uint size)
> > > > return log_msg_ret("Bad checksum", -EIO);
> > > > }
> > > > gd->bloblist = hdr;
> > > > + gd->flags |= GD_FLG_BLOBLIST_READY;
> > > >
> > > > return 0;
> > > > }
> > > > @@ -576,90 +578,88 @@ int __weak xferlist_from_boot_arg(ulong __always_unused *addr)
> > > > return -ENOENT;
> > > > }
> > > >
> > > > -int bloblist_init(void)
> > > > +bool bloblist_exists(void)
> > > > {
> > > > - bool fixed = IS_ENABLED(CONFIG_BLOBLIST_FIXED);
> > > > - int ret = 0;
> > > > - ulong addr = 0, size;
> > > > + int ret;
> > > > + ulong addr = 0;
> > > >
> > > > /* Check if a valid transfer list passed in */
> > > > - if (!xferlist_from_boot_arg(&addr)) {
> > > > - size = bloblist_get_total_size();
> > > > - } else {
> > > > - /*
> > > > - * If U-Boot is not in the first phase, an existing bloblist must
> > > > - * be at a fixed address.
> > > > - */
> > > > - bool from_addr = fixed && !xpl_is_first_phase();
> > > > -
> > > > - /*
> > > > - * If Firmware Handoff is mandatory but no transfer list is
> > > > - * observed, report it as an error.
> > > > - */
> > > > - if (IS_ENABLED(CONFIG_BLOBLIST_PASSAGE_MANDATORY))
> > > > - return -ENOENT;
> > > > -
> > > > - ret = -ENOENT;
> > > > -
> > > > - if (xpl_prev_phase() == PHASE_TPL &&
> > > > - !IS_ENABLED(CONFIG_TPL_BLOBLIST))
> > > > - from_addr = false;
> > > > - if (fixed)
> > > > - addr = IF_ENABLED_INT(CONFIG_BLOBLIST_FIXED,
> > > > - CONFIG_BLOBLIST_ADDR);
> > > > - size = CONFIG_BLOBLIST_SIZE;
> > > > -
> > > > - if (from_addr)
> > > > - ret = bloblist_check(addr, size);
> > > > + if (!xferlist_from_boot_arg(&addr))
> > > > + goto found;
> > > >
> > > > - if (ret)
> > > > - log_debug("Bloblist at %lx not found (err=%d)\n",
> > > > - addr, ret);
> > > > - else
> > > > - /* Get the real size */
> > > > - size = gd->bloblist->total_size;
> > > > - }
> > > > + /*
> > > > + * If Firmware Handoff is mandatory but no transfer list is
> > > > + * observed, report it as an error.
> > > > + */
> > > > + if (IS_ENABLED(CONFIG_BLOBLIST_PASSAGE_MANDATORY))
> > > > + return false;
> > > >
> > > > - if (ret) {
> > > > - /*
> > > > - * If we don't have a bloblist from a fixed address, or the one
> > > > - * in the fixed address is not valid. we must allocate the
> > > > - * memory for it now.
> > > > - */
> > > > - if (CONFIG_IS_ENABLED(BLOBLIST_ALLOC)) {
> > > > - void *ptr = memalign(BLOBLIST_ALIGN, size);
> > > > -
> > > > - if (!ptr)
> > > > - return log_msg_ret("alloc", -ENOMEM);
> > > > - addr = map_to_sysmem(ptr);
> > > > - } else if (!fixed) {
> > > > - return log_msg_ret("BLOBLIST_FIXED is not enabled",
> > > > - ret);
> > > > - }
> > > > - log_debug("Creating new bloblist size %lx at %lx\n", size,
> > > > - addr);
> > > > - ret = bloblist_new(addr, size, 0, 0);
> > > > - } else {
> > > > - log_debug("Found existing bloblist size %lx at %lx\n", size,
> > > > - addr);
> > > > - }
> > > > + /*
> > > > + * We have checked for a valid transfer list being passed. At this
> > > > + * point, if we do not have a fixed address for the bloblist, we cannot
> > > > + * be provided with one.
> > > > + */
> > > > + if (xpl_is_first_phase() || !IS_ENABLED(CONFIG_BLOBLIST_FIXED))
> > > > + return false;
> > > >
> > > > - if (ret)
> > > > - return log_msg_ret("ini", ret);
> > > > - gd->flags |= GD_FLG_BLOBLIST_READY;
> > > > + /*
> > > > + * Check for a valid list as the configured address.
> > > > + */
> > > > + addr = IF_ENABLED_INT(CONFIG_BLOBLIST_FIXED,
> > > > + CONFIG_BLOBLIST_ADDR);
> > > > + ret = bloblist_check(addr, CONFIG_BLOBLIST_SIZE);
> > > > + if (!ret)
> > > > + goto found;
> > > > +
> > > > + log_debug("Bloblist at %lx not found (err=%d)\n", addr, ret);
> > > > + return false;
> > > >
> > > > +found:
> > > > #ifdef DEBUG
> > > > bloblist_show_stats();
> > > > bloblist_show_list();
> > > > #endif
> > > > -
> > > > - return 0;
> > > > + return true;
> > > > }
> > > >
> > > > -int bloblist_maybe_init(void)
> > > > +int bloblist_init(void)
> > > > {
> > > > - if (CONFIG_IS_ENABLED(BLOBLIST) && !(gd->flags & GD_FLG_BLOBLIST_READY))
> > > > - return bloblist_init();
> > > > + int ret;
> > > > + ulong addr = 0, size = CONFIG_BLOBLIST_SIZE;
> > > > +
> > > > + if (gd->flags & GD_FLG_BLOBLIST_READY) {
> > > > + log_debug("Found existing bloblist size %x at %p\n",
> > > > + gd->bloblist->total_size, gd->bloblist);
> > > > + return 0;
> > > > + }
> > > > +
> > > > + /*
> > > > + * If Firmware Handoff is mandatory but no transfer list has been
> > > > + * observed by fdtdec_setup, report it as an error.
> > > > + */
> > > > + if (IS_ENABLED(CONFIG_BLOBLIST_PASSAGE_MANDATORY))
> > > > + return -ENOENT;
> > > > +
> > > > + /*
> > > > + * If we don't have an existing bloblist, we either need
> > > > + * to allocate one now, or initialize the fixed address
> > > > + * space as a bloblist.
> > > > + */
> > > > + if (CONFIG_IS_ENABLED(BLOBLIST_ALLOC)) {
> > > > + void *ptr = memalign(BLOBLIST_ALIGN, size);
> > > > +
> > > > + if (!ptr)
> > > > + return log_msg_ret("alloc", -ENOMEM);
> > > > + addr = map_to_sysmem(ptr);
> > > > + } else
> > > > + addr = IF_ENABLED_INT(CONFIG_BLOBLIST_FIXED,
> > > > + CONFIG_BLOBLIST_ADDR);
> > > > +
> > > > + log_debug("Creating new bloblist size %lx at %lx\n", size,
> > > > + addr);
> > > > + ret = bloblist_new(addr, size, 0, 0);
> > > > + if (ret)
> > > > + return log_msg_ret("ini", ret);
> > > >
> > > > return 0;
> > > > }
> > > > @@ -687,7 +687,9 @@ int bloblist_check_reg_conv(ulong rfdt, ulong rzero, ulong rsig, ulong xlist)
> > > > return ret;
> > > >
> > > > if (rfdt != (ulong)bloblist_find(BLOBLISTT_CONTROL_FDT, 0)) {
> > > > - gd->bloblist = NULL; /* Reset the gd bloblist pointer */
> > > > + /* Remove this bloblist from gd */
> > > > + gd->bloblist = NULL;
> > > > + gd->flags &= ~GD_FLG_BLOBLIST_READY;
> > > > return -EIO;
> > > > }
> > > >
> > > > diff --git a/common/board_f.c b/common/board_f.c
> > > > index ce87c619e680..c39e3b940d3b 100644
> > > > --- a/common/board_f.c
> > > > +++ b/common/board_f.c
> > > > @@ -894,7 +894,9 @@ static void initcall_run_f(void)
> > > > INITCALL(log_init);
> > > > INITCALL(initf_bootstage); /* uses its own timer, so does not need DM */
> > > > INITCALL(event_init);
> > > > - INITCALL(bloblist_maybe_init);
> > > > +#if CONFIG_IS_ENABLED(BLOBLIST)
> > > > + INITCALL(bloblist_init);
> > > > +#endif
> > > > INITCALL(setup_spl_handoff);
> > > > #if CONFIG_IS_ENABLED(CONSOLE_RECORD_INIT_F)
> > > > INITCALL(console_record_init);
> > > > diff --git a/include/bloblist.h b/include/bloblist.h
> > > > index e67b2a76358d..4c5787729654 100644
> > > > --- a/include/bloblist.h
> > > > +++ b/include/bloblist.h
> > > > @@ -488,10 +488,24 @@ const char *bloblist_tag_name(enum bloblist_tag_t tag);
> > > > */
> > > > int bloblist_reloc(void *to, uint to_size);
> > > >
> > > > +/**
> > > > + * bloblist_exists() - Check for the prior existence of a bloblist
> > > > + *
> > > > + * This will check for a transfer list having been passed via standard
> > > > + * convention. If CONFIG_BLOBLIST_PASSAGE_MANDATORY is selected and one is not
> > > > + * found, we return false.
> > > > + *
> > > > + * If CONFIG_BLOBLIST_FIXED is selected, it uses CONFIG_BLOBLIST_ADDR and
> > > > + * CONFIG_BLOBLIST_SIZE to check for a bloblist.
> > > > + *
> > > > + * Return: true if found, false if not
> > > > + */
> > > > +bool bloblist_exists(void);
> > > > +
> > > > /**
> > > > * bloblist_init() - Init the bloblist system with a single bloblist
> > > > *
> > > > - * This locates and sets up the blocklist for use.
> > > > + * This creates a bloblist for use, if not already found.
> > > > *
> > > > * If CONFIG_BLOBLIST_FIXED is selected, it uses CONFIG_BLOBLIST_ADDR and
> > > > * CONFIG_BLOBLIST_SIZE to set up a bloblist for use by U-Boot.
> > > > @@ -508,22 +522,6 @@ int bloblist_reloc(void *to, uint to_size);
> > > > */
> > > > int bloblist_init(void);
> > > >
> > > > -#if CONFIG_IS_ENABLED(BLOBLIST)
> > > > -/**
> > > > - * bloblist_maybe_init() - Init the bloblist system if not already done
> > > > - *
> > > > - * Calls bloblist_init() if the GD_FLG_BLOBLIST_READY flag is not set
> > > > - *
> > > > - * Return: 0 if OK, -ve on error
> > > > - */
> > > > -int bloblist_maybe_init(void);
> > > > -#else
> > > > -static inline int bloblist_maybe_init(void)
> > > > -{
> > > > - return 0;
> > > > -}
> > > > -#endif /* BLOBLIST */
> > > > -
> > > > /**
> > > > * bloblist_check_reg_conv() - Check whether the bloblist is compliant to
> > > > * the register conventions according to the
> > > > diff --git a/lib/fdtdec.c b/lib/fdtdec.c
> > > > index c67b6e8c133e..7fd7f7ff01e5 100644
> > > > --- a/lib/fdtdec.c
> > > > +++ b/lib/fdtdec.c
> > > > @@ -1822,17 +1822,12 @@ int fdtdec_setup(void)
> > > > int ret = -ENOENT;
> > > >
> > > > /*
> > > > - * If allowing a bloblist, check that first. There was discussion about
> > > > - * adding an OF_BLOBLIST Kconfig, but this was rejected.
> > > > - *
> > > > - * The necessary test is whether the previous phase passed a bloblist,
> > > > - * not whether this phase creates one.
> > > > + * If allowing a bloblist, check that first. The necessary test is
> > > > + * whether the previous phase passed a bloblist, not whether this phase
> > > > + * creates one.
> > > > */
> > > > - if (CONFIG_IS_ENABLED(BLOBLIST) &&
> > > > - (xpl_prev_phase() != PHASE_TPL ||
> > > > - IS_ENABLED(CONFIG_TPL_BLOBLIST))) {
> > > > - ret = bloblist_maybe_init();
> > > > - if (!ret) {
> > > > + if (CONFIG_IS_ENABLED(BLOBLIST) && (xpl_prev_phase() != PHASE_TPL)) {
> > >
> > > I think this change drops the TPL-provided blobs on TPL->SPL boots.
> > > When TPL_BLOBLIST is selected, the next phase starts with
> > > xpl_prev_phase() == PHASE_TPL.
> > > This new guard now skips bloblist_exists(), so gd->flags never gets
> > > GD_FLG_BLOBLIST_READY; the later bloblist_init() in common/spl/spl.c
> > > then creates a fresh bloblist and overwrites the fixed-address list
> > > from TPL.
> >
> > Ah right, oops. I guess the only question is if we should continue to
> > optimize the TPL case (it can't exist) or just always check (maybe
> > there's some 4 stage boot..).
> >
>
> That really depends on whether we shall consider the scenario of TPL.
> For the case of the Arm Firmware Handoff, stages before BL2 are not
> considered to hand information over to the next stage via Transfer
> List (aka. bloblist in U-Boot).
OK, I think we can just go with SPL or higher looks for a bloblist, TPL
can create one but not be passed one. It's simple enough to change if
there's somehow a 4 stage boot we need to worry about later.
--
Tom
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