Re: [PATCH 02/19] ARM: mvebu: add lowlevel support for Netgear RN102

["Sascha Hauer" <s.hauer@pengutronix.de>]

On 2026-07-23 15:57, Luca Lauro via B4 Relay wrote:
> From: Luca Lauro <famlauro93l@gmail.com>
> 
> ---
>  arch/arm/boards/netgear-rn102/lowlevel.c | 49 ++++++++++++++++++++++++++++++++
>  1 file changed, 49 insertions(+)
> 
> diff --git a/arch/arm/boards/netgear-rn102/lowlevel.c b/arch/arm/boards/netgear-rn102/lowlevel.c
> new file mode 100644
> index 0000000000..11130eabbc
> --- /dev/null
> +++ b/arch/arm/boards/netgear-rn102/lowlevel.c
> @@ -0,0 +1,49 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <common.h>
> +#include <asm/barebox-arm.h>
> +#include <mach/mvebu/lowlevel.h>
> +#include <mach/mvebu/barebox-arm-head.h>
> +#include <mach/mvebu/armada-370-xp-regs.h>
> +
> +extern char __dtb_armada_370_rn102_bb_start[];
> +
> +#define INTERNAL_REG_BASE_ADDR	0x20080
> +
> +static __always_inline void mvebu_remap_registers(void)
> +{
> +	void __iomem *base = mvebu_get_initial_int_reg_base();
> +
> +	writel(MVEBU_REMAP_INT_REG_BASE, base + INTERNAL_REG_BASE_ADDR);
> +}
> +
> +static unsigned long armada_370_xp_memory_find(void)
> +{
> +	unsigned long mem_size = 0;
> +
> +	for (int cs = 0; cs < 4; cs++) {
> +		u32 ctrl = readl(ARMADA_370_XP_SDRAM_BASE + DDR_SIZE_CSn(cs));
> +
> +		/* Skip non-enabled CS */
> +		if ((ctrl & DDR_SIZE_ENABLED) != DDR_SIZE_ENABLED)
> +			continue;
> +
> +		mem_size += (ctrl | ~DDR_SIZE_MASK) + 1;
> +	}
> +
> +	return mem_size;
> +}
> +
> +ENTRY_FUNCTION_MVEBU(start_netgear_rn102, r0, r1, r2)
> +{
> +    void *fdt;
> +
> +    arm_cpu_lowlevel_init();
> +	
> +	fdt = __dtb_armada_370_rn102_bb_start +
> +		get_runtime_offset();
> +
> +	mvebu_remap_registers();
> +	barebox_arm_entry(0, armada_370_xp_memory_find(), fdt);
> +	// armada_370_xp_barebox_entry(fdt);

Why can't you use armada_370_xp_barebox_entry()? I assume that wrongly
detects the amount of memory. If that's the case the preferred way would
be to fix the SDRAM detection code. If that's not feasible, please leave
an explanation in the code why it doesn't work and drop the commented
out call.

Sascha

--
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |