Dear Rob Herring,
In message 1359085160-28675-1-git-send-email-robherring2@gmail.com you wrote:
Currently, u-boot will always fixup the DT memory node on ARM. If the dtb has correct memory information, then we don't want or need u-boot to touch the memory node. Allow platforms to skip this by not filling in dram bank information.
Well, if this is what you want, then please implement just this, and do not do much more.
void __dram_init_banksize(void) { +#if CONFIG_NR_DRAM_BANKS gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE; gd->bd->bi_dram[0].size = gd->ram_size; +#endif }
This change will leave the memory information in struct bd_info uninitialized, so the "bdinfo" command will print just bogus data.
This is not a good idea.
--- a/arch/arm/lib/bootm.c +++ b/arch/arm/lib/bootm.c @@ -79,6 +79,7 @@ void arch_lmb_reserve(struct lmb *lmb) #ifdef CONFIG_OF_LIBFDT static int fixup_memory_node(void *blob) { +#if CONFIG_NR_DRAM_BANKS bd_t *bd = gd->bd; int bank; u64 start[CONFIG_NR_DRAM_BANKS]; @@ -90,6 +91,9 @@ static int fixup_memory_node(void *blob) }
return fdt_fixup_memory_banks(blob, start, size, CONFIG_NR_DRAM_BANKS); +#else
- return 0;
+#endif
I dislike this. If you want to make a property of your device tree "immutable", then you should mark it there as such. Instead of removing the code here, U-Boot should then check for such a property and leave the value unchanged.
Actually you are reaching here a point where it seems necessary that U-Boot itself is able to read the DT to configure itself correctly, i. e. the memory size information it holds should then also be extracted from the DT.
Best regards,
Wolfgang Denk