On Fri, Feb 19, 2021 at 09:46:49PM +0000, Aleksandar Gerasimovski wrote:
This is a draft patch to describe the problem and to initiate a discussion for solution.
PRAM usage is not taken into account when reserving lmb for ARM architecture, this means that predefined PRAM region is reserved by the u-boot and cannot be used by the u-boot users.
In our case this bug leads to non functional ramfs boot, as the PRAM and ram rootfs address ranges are getting reserved by the u-boot.
It is obvious that here PRAM region is ignored, but my question is is this clear to everyone and expected?
Taking board_f.c as reference, when calculating relocation address PRAM area is taken into account so I would expect that to be case here. Here the intention is to reserve unused space at the end of the effective RAM but PRAM is not part of that.
Possible solution would be to introduce something like get_effective_memsize here e.g powerpc/lib/bootm.c but then also NR_DRAM_BANKS has to be considered?
Signed-off-by: Aleksandar Gerasimovski aleksandar.gerasimovski@hitachi-powergrids.com
arch/arm/lib/bootm.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c index 11af9e2..4b06d25 100644 --- a/arch/arm/lib/bootm.c +++ b/arch/arm/lib/bootm.c @@ -54,7 +54,7 @@ static ulong get_sp(void)
void arch_lmb_reserve(struct lmb *lmb) {
- ulong sp, bank_end;
ulong sp, bank_end, pram = 0; int bank;
/*
@@ -69,6 +69,11 @@ void arch_lmb_reserve(struct lmb *lmb) sp = get_sp(); debug("## Current stack ends at 0x%08lx ", sp);
+#ifdef CONFIG_PRAM
- pram = env_get_ulong("pram", 10, CONFIG_PRAM);
- pram = pram << 10; /* size is in kB */
+#endif
- /* adjust sp by 4K to be safe */ sp -= 4096; for (bank = 0; bank < CONFIG_NR_DRAM_BANKS; bank++) {
@@ -76,8 +81,9 @@ void arch_lmb_reserve(struct lmb *lmb) sp < gd->bd->bi_dram[bank].start) continue; /* Watch out for RAM at end of address space! */
/* @todo: pram obviously wrong if NR_DRAM_BANKS > 1 */
gd->bd->bi_dram[bank].size - 1;
gd->bd->bi_dram[bank].size - pram - 1;
Adding a few folks who have touched lmb code relatively recently for their thoughts. Thanks!