[PATCH v1] arm: snapdragon: Add EFI reserved memory regions for QCS615/QCM6490
Ilias Apalodimas
ilias.apalodimas at linaro.org
Thu Jan 15 07:48:24 CET 2026
On Wed, 14 Jan 2026 at 16:44, Casey Connolly <casey.connolly at linaro.org> wrote:
>
> Hi Balaji,
>
> No, we aren't adding platform-specific hardcoded memory maps to U-Boot.
> Reserved memory should be specified in devicetree and added to the EFI
> memory map automatically (Ilias?).
Yes, the reserved memory regions should only be added to the DT. The
EFI subsystem will scan that and mark it as EiReserved
(efi_carve_out_dt_rsv()). We want to keep the DT and the efi memory
mnap in sync
Cheers
/Ilias
>
> Kind regards,
>
> On 07/01/2026 10:14, Balaji Selvanathan wrote:
> > Implemented platform-specific reserved memory registration for EFI on
> > Qualcomm Snapdragon platforms. This adds SoC-specific memory regions
> > to the EFI memory map.
> >
> > Added qcom_reserved_memory.c with predefined memory regions for QCS615
> > and QCM6490/SC7280 SoCs. The implementation detects the SoC type
> > from device tree and registers appropriate memory regions
> > via efi_add_memory_map().
> >
> > Implemented efi_add_known_memory() in board.c to hook into the EFI
> > memory initialization.
> >
> > Signed-off-by: Balaji Selvanathan <balaji.selvanathan at oss.qualcomm.com>
> > ---
> > arch/arm/mach-snapdragon/Makefile | 1 +
> > arch/arm/mach-snapdragon/board.c | 15 +++
> > arch/arm/mach-snapdragon/qcom-priv.h | 10 ++
> > .../mach-snapdragon/qcom_reserved_memory.c | 114 ++++++++++++++++++
> > 4 files changed, 140 insertions(+)
> > create mode 100644 arch/arm/mach-snapdragon/qcom_reserved_memory.c
> >
> > diff --git a/arch/arm/mach-snapdragon/Makefile b/arch/arm/mach-snapdragon/Makefile
> > index 343e825c6fd..19820a075e8 100644
> > --- a/arch/arm/mach-snapdragon/Makefile
> > +++ b/arch/arm/mach-snapdragon/Makefile
> > @@ -4,4 +4,5 @@
> >
> > obj-y += board.o
> > obj-$(CONFIG_EFI_HAVE_CAPSULE_SUPPORT) += capsule_update.o
> > +obj-$(CONFIG_EFI_LOADER) += qcom_reserved_memory.o
> > obj-$(CONFIG_OF_LIVE) += of_fixup.o
> > diff --git a/arch/arm/mach-snapdragon/board.c b/arch/arm/mach-snapdragon/board.c
> > index 5fb3240acc5..0259623d382 100644
> > --- a/arch/arm/mach-snapdragon/board.c
> > +++ b/arch/arm/mach-snapdragon/board.c
> > @@ -709,6 +709,21 @@ static void carve_out_reserved_memory(void)
> > }
> > }
> >
> > +#ifdef CONFIG_EFI_LOADER
> > +/**
> > + * efi_add_known_memory() - Add platform-specific reserved memory to EFI map
> > + *
> > + * This function is called by the EFI memory initialization code to allow
> > + * platforms to add their reserved memory regions to the EFI memory map.
> > + * For Qualcomm platforms, this delegates to qcom_add_reserved_memory_to_efi()
> > + * which handles SoC-specific reserved memory regions.
> > + */
> > +void efi_add_known_memory(void)
> > +{
> > + qcom_add_reserved_memory_to_efi();
> > +}
> > +#endif /* CONFIG_EFI_LOADER */
> > +
> > /* This function open-codes setup_all_pgtables() so that we can
> > * insert additional mappings *before* turning on the MMU.
> > */
> > diff --git a/arch/arm/mach-snapdragon/qcom-priv.h b/arch/arm/mach-snapdragon/qcom-priv.h
> > index b8bf574e8bb..b488516cfdb 100644
> > --- a/arch/arm/mach-snapdragon/qcom-priv.h
> > +++ b/arch/arm/mach-snapdragon/qcom-priv.h
> > @@ -17,6 +17,16 @@ enum qcom_boot_source {
> >
> > extern enum qcom_boot_source qcom_boot_source;
> >
> > +#if IS_ENABLED(CONFIG_EFI_LOADER)
> > +/**
> > + * qcom_add_reserved_memory_to_efi() - Add Qualcomm SoC reserved memory to EFI
> > + *
> > + * This function detects the SoC type and adds the appropriate reserved
> > + * memory regions to the EFI memory map. Called from efi_add_known_memory().
> > + */
> > +void qcom_add_reserved_memory_to_efi(void);
> > +#endif /* CONFIG_EFI_LOADER */
> > +
> > #if IS_ENABLED(CONFIG_EFI_HAVE_CAPSULE_SUPPORT)
> > void qcom_configure_capsule_updates(void);
> > #else
> > diff --git a/arch/arm/mach-snapdragon/qcom_reserved_memory.c b/arch/arm/mach-snapdragon/qcom_reserved_memory.c
> > new file mode 100644
> > index 00000000000..e670f74bc1f
> > --- /dev/null
> > +++ b/arch/arm/mach-snapdragon/qcom_reserved_memory.c
> > @@ -0,0 +1,114 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> > + */
> > +
> > +#include <efi_loader.h>
> > +#include <fdt_support.h>
> > +#include <log.h>
> > +#include <linux/sizes.h>
> > +#include <asm/global_data.h>
> > +#include "qcom-priv.h"
> > +
> > +DECLARE_GLOBAL_DATA_PTR;
> > +
> > +/**
> > + * struct reserved_mem_region - Reserved memory region descriptor
> > + * @start: Physical start address of the region
> > + * @size: Size of the region in bytes
> > + * @name: Human-readable name for logging
> > + */
> > +struct reserved_mem_region {
> > + u64 start;
> > + u64 size;
> > + const char *name;
> > +};
> > +
> > +/* QCS615 reserved memory regions */
> > +static const struct reserved_mem_region qcs615_reserved[] = {
> > + { 0x80000000, 0x600000, "hyp" },
> > + { 0x85D00000, 0x200000, "boot" },
> > + { 0x85F00000, 0x20000, "aop" },
> > + { 0x85F40000, 0x30000, "xbl_dt" },
> > + { 0x86200000, 0x100000, "tz_stat" },
> > + { 0x86300000, 0x1200000, "tags" },
> > + { 0x87500000, 0x500000, "tz" },
> > + { 0x87A00000, 0x1C00000, "tzapps" },
> > + { 0x8AB00000, 0xCC17000, "pil" },
> > + { 0xA0000000, 0x1600000, "secure_dsp" },
> > +};
> > +
> > +/* SC7280/QCM6490 reserved memory regions */
> > +static const struct reserved_mem_region sc7280_reserved[] = {
> > + { 0x80600000, 0x100000, "axon_dma" },
> > + { 0x80894000, 0x40000, "xbl_dt" },
> > + { 0x84300000, 0x16B00000, "pil_reserved" },
> > + { 0xE1000000, 0x2400000, "display" },
> > +};
> > +
> > +/**
> > + * add_soc_reserved_memory() - Add SoC-specific reserved memory to EFI map
> > + * @regions: Array of reserved memory regions
> > + * @count: Number of regions in the array
> > + * @soc_name: SoC name for logging
> > + *
> > + * This function iterates through the provided reserved memory regions and
> > + * adds them to the EFI memory map with type EFI_RESERVED_MEMORY_TYPE.
> > + */
> > +static void add_soc_reserved_memory(const struct reserved_mem_region *regions,
> > + int count, const char *soc_name)
> > +{
> > + int i;
> > +
> > + log_debug("Adding %s reserved memory to EFI map (%d regions)\n",
> > + soc_name, count);
> > +
> > + for (i = 0; i < count; i++) {
> > + efi_status_t ret;
> > +
> > + ret = efi_add_memory_map(regions[i].start,
> > + regions[i].size,
> > + EFI_RESERVED_MEMORY_TYPE);
> > +
> > + if (ret != EFI_SUCCESS) {
> > + log_err("%s: Failed to reserve %s (0x%llx-0x%llx): %lu\n",
> > + soc_name, regions[i].name,
> > + regions[i].start,
> > + regions[i].start + regions[i].size,
> > + ret & ~EFI_ERROR_MASK);
> > + } else {
> > + log_debug("%s: Reserved %s: 0x%llx-0x%llx (%llu KB)\n",
> > + soc_name, regions[i].name,
> > + regions[i].start,
> > + regions[i].start + regions[i].size,
> > + regions[i].size / 1024);
> > + }
> > + }
> > +}
> > +
> > +/**
> > + * qcom_add_reserved_memory_to_efi() - Add Qualcomm SoC reserved memory to EFI
> > + *
> > + * This function detects the SoC type from the device tree and adds the
> > + * appropriate reserved memory regions to the EFI memory map.
> > + *
> > + * Supported SoCs:
> > + * - QCS615 (Talos)
> > + * - QCM6490/SC7280 (Kodiak)
> > + */
> > +void qcom_add_reserved_memory_to_efi(void)
> > +{
> > + /* Detect SoC and add appropriate reserved memory */
> > + if (fdt_node_check_compatible(gd->fdt_blob, 0, "qcom,qcs615") == 0) {
> > + add_soc_reserved_memory(qcs615_reserved,
> > + ARRAY_SIZE(qcs615_reserved),
> > + "QCS615");
> > + } else if (fdt_node_check_compatible(gd->fdt_blob, 0, "qcom,qcm6490") == 0 ||
> > + fdt_node_check_compatible(gd->fdt_blob, 0, "qcom,sc7280") == 0) {
> > + add_soc_reserved_memory(sc7280_reserved,
> > + ARRAY_SIZE(sc7280_reserved),
> > + "QCM6490/SC7280");
> > + } else {
> > + log_debug("No SoC-specific reserved memory to add\n");
> > + }
> > +}
>
> --
> // Casey (she/her)
>
More information about the U-Boot
mailing list