[PATCH v7 0/7] Relocate U-Boot in the last bank

Christophe Leroy (CS GROUP) chleroy at kernel.org
Tue Jun 23 15:13:53 CEST 2026


Hi,

Le 17/06/2026 à 09:48, Ilias Apalodimas a écrit :
> Hi all, this is v7 of [1][2][3][4][5][6]!
> 
> There was a discussion recently on the mailing lists regarding our
> management of memory above ram_top [0]. The tl;dr is that we have two problems.
> 
> The first one is that U-Boot always relocates to the top of the first available
> bank unless there's special board code to sidestep that. The second is we don't
> successfully deal with devices that can only do 32-bit DMA.
> 
> This patch series deals with the first problem by adding a Kconfig option
> allowing platforms to relocate to the top of the last discovered bank.
> 
> It's worth noting that this is easily testable with QEMU

Following discussion on patch 1/7 in v5, I boot tested this v7 series on 
one of my powerpc boards. It could start Linux kernel v7.0 without any 
problem.

FWIW,

Tested-by: Christophe Leroy (CS GROUP) <chleroy at kernel.org>

Christophe

> 
> qemu-system-aarch64 -m 8192 -smp 2 -nographic -cpu cortex-a57 \
>      -machine virt,secure=off \
>      -bios u-boot.bin \
>      -device virtio-rng-pci \
>      -drive id=os,if=none,file="$image" \
>      -device virtio-blk-device,drive=os \
>      -object memory-backend-ram,id=ram0,size=4G \
>      -object memory-backend-ram,id=ram1,size=4G \
>      -numa node,memdev=ram0 \
>      -numa node,memdev=ram1
> 
> # RELOC_ADDR_TOP not set
> Hit any key to stop autoboot: 0
> => bdinfo
> [...]
> relocaddr   = 0x000000013f66c000
> reloc off   = 0x000000013f66c000
> [...]
> lmb_dump_all:
>   memory.count = 0x1
>   memory[0]	[0x40000000-0x23fffffff], 0x200000000 bytes, flags: none
>   reserved.count = 0x2
>   reserved[0]	[0x13d507000-0x13d509fff], 0x3000 bytes, flags: no-notify, no-overwrite
> reserved[1]	[0x13d50aff0-0x23fffffff], 0x102af5010 bytes, flags: no-overwrite
> devicetree  = board
> [...]
> TLB addr    = 0x000000013ffe0000
> irq_sp      = 0x000000013e50aff0
> sp start    = 0x000000013e50aff0
> Early malloc usage: e88 / 2000
> =>
> 
> # RELOC_ADDR_TOP enabled
> 
> => bdinfo
> [...]
> relocaddr   = 0x000000023f66c000
> reloc off   = 0x000000023f66c000
> [...]
> lmb_dump_all:
>   memory.count = 0x1
>   memory[0]	[0x40000000-0x23fffffff], 0x200000000 bytes, flags: none
>   reserved.count = 0x2
>   reserved[0]	[0x23d507000-0x23d509fff], 0x3000 bytes, flags: no-notify, no-overwrite
>   reserved[1]	[0x23d50aff0-0x23fffffff], 0x2af5010 bytes, flags: no-overwrite
> devicetree  = board
> [...]
> TLB addr    = 0x000000023ffe0000
> irq_sp      = 0x000000023e50aff0
> sp start    = 0x000000023e50aff0
> Early malloc usage: e88 / 2000
> =>
> 
> [1] https://lore.kernel.org/u-boot/20260403090109.3564638-1-ilias.apalodimas@linaro.org/
> [2] https://lore.kernel.org/u-boot/CAC_iWj+JmwW6gDmUf76OX0WiW+RQy-DA2STs+ROHH-i0AbGJ2A@mail.gmail.com/T/#t
> [3] https://lore.kernel.org/u-boot/20260427100832.581887-1-ilias.apalodimas@linaro.org/
> [4] https://lore.kernel.org/u-boot/20260515135245.45067-1-ilias.apalodimas@linaro.org/
> [5] https://lore.kernel.org/u-boot/20260604073719.48723-1-ilias.apalodimas@linaro.org/
> [6] https://lore.kernel.org/u-boot/20260609131611.46399-1-ilias.apalodimas@linaro.org/
> 
> Marek, I've kept your r-b on patch #5 since the changes seem minor and won't
> affect anything for now
> 
> Changes since v6:
> - Mention QEMU on patch #6
> - Remove redundant depends on EXPERT
> - Rebase on top of -next
> 
> Changes since v5:
> - Call board_get_usable_ram_top() with mon_len until we decide what's best
>    for the common code (mon_len is what we used up to now)
> - Address some comments from Simon on the documentation
> - Reduce ram_top as well as ram_size when CONFIG_SYS_MEM_TOP_HIDE is defined
> 
> Changes since v4:
> - Use CONFIG_VAL instead of IS_ENABLED for SYS_MEM_TOP_HIDE
> - Fix RPi4 hang
> 
> Changes since v3:
> - Use (aligned) gd->mon_len for the get_mem_top() size argument instead of 0.
>    Using !0 will properly factor in reserved regions before calculating the
>    reloc address
> - Call board_get_usable_ram_top() regardless of the config option so
>    boards can tweak the address eventually
> - Don't rely on the fact that banks are populated in ascending order
> - Updated the Kconfig description wrt 32-bit boundaries
> - Fixed array comment in include/init.h
> - Don't carry Marek's patches. We can resend those once we have actual users
> 
> Changes since v2:
> - Rename bi_dram to dram apart from moving it to gd
> - Adjusted a Kconfig description and a commit message on patch #6
> - Use get_mem_top() instead of calculating the top address adding the
>    dram bank info. That function will account for the reserved memory regions
>    and exclude them
> - Collected Tested/Reviewed-by tags
> 
> Changes since v1:
> - Rebased and added Marek's cleanup patches
> - Remove the ifdefery on patch #6 in favor of 'if (CONFIG_IS_ENABLED)'
> - Added a warning on the Kconfig message about breaking devices that
>    can't DMA to high memory
> - Added depends on EXPERT for relocatiing to the last bank
> - Using %llx instead of %llX on debug prints
> - Removed 2 remaining comments of bd->bi_dram[]
> - Collected Tested/Reviewed-by tags
> 
> Ilias Apalodimas (7):
>    treewide: move bi_dram[] from bd to gd
>    common: move ram_base calculation to independent INITCALL()
>    common: Clean up setup_dest_addr()
>    rpi: Add a local get_effective_memsize()
>    common: Add an option to relocate on ram top
>    configs: Enable RELOC_ADDR_TOP on arm64 QEMU
>    doc: Add a warning about using RELOC_ADDR_TOP
> 
>   Kconfig                                       |  13 ++
>   api/api_platform.c                            |   4 +-
>   arch/arm/cpu/armv8/cache_v8.c                 |   6 +-
>   arch/arm/cpu/armv8/fsl-layerscape/cpu.c       | 118 +++++++++---------
>   arch/arm/lib/bootm-fdt.c                      |   5 +-
>   arch/arm/lib/bootm.c                          |   4 +-
>   arch/arm/lib/cache-cp15.c                     |   9 +-
>   arch/arm/lib/image.c                          |   2 +-
>   arch/arm/mach-airoha/an7581/init.c            |   8 +-
>   arch/arm/mach-apple/board.c                   |   4 +-
>   arch/arm/mach-davinci/misc.c                  |   4 +-
>   arch/arm/mach-imx/ele_ahab.c                  |   7 +-
>   arch/arm/mach-imx/imx8/ahab.c                 |   7 +-
>   arch/arm/mach-imx/imx8/cpu.c                  |  44 +++----
>   arch/arm/mach-imx/imx8m/soc.c                 |  24 ++--
>   arch/arm/mach-imx/imx8ulp/soc.c               |  20 +--
>   arch/arm/mach-imx/imx9/scmi/soc.c             |  24 ++--
>   arch/arm/mach-imx/imx9/soc.c                  |  24 ++--
>   arch/arm/mach-imx/mx5/mx53_dram.c             |   8 +-
>   arch/arm/mach-imx/spl.c                       |   4 +-
>   arch/arm/mach-k3/k3-ddr.c                     |   4 +-
>   arch/arm/mach-mvebu/alleycat5/cpu.c           |   4 +-
>   arch/arm/mach-mvebu/armada3700/cpu.c          |  10 +-
>   arch/arm/mach-mvebu/armada8k/dram.c           |  10 +-
>   arch/arm/mach-mvebu/dram.c                    |   6 +-
>   arch/arm/mach-omap2/am33xx/board.c            |   4 +-
>   arch/arm/mach-omap2/omap-cache.c              |   5 +-
>   arch/arm/mach-omap2/omap3/emif4.c             |   8 +-
>   arch/arm/mach-omap2/omap3/sdrc.c              |   8 +-
>   arch/arm/mach-owl/soc.c                       |   4 +-
>   arch/arm/mach-renesas/memmap-gen3.c           |   8 +-
>   arch/arm/mach-renesas/memmap-rzg2l.c          |   4 +-
>   arch/arm/mach-rockchip/rk3588/rk3588.c        |   8 +-
>   arch/arm/mach-rockchip/sdram.c                |  42 +++----
>   arch/arm/mach-snapdragon/board.c              |  16 +--
>   arch/arm/mach-socfpga/board.c                 |   5 +-
>   arch/arm/mach-socfpga/misc_arria10.c          |   7 +-
>   .../mach-stm32mp/cmd_stm32prog/stm32prog.c    |   4 +-
>   arch/arm/mach-stm32mp/stm32mp1/cpu.c          |   7 +-
>   arch/arm/mach-tegra/board2.c                  |  14 +--
>   arch/arm/mach-tegra/cboot.c                   |   4 +-
>   arch/arm/mach-uniphier/dram_init.c            |   6 +-
>   arch/arm/mach-uniphier/fdt-fixup.c            |   8 +-
>   arch/arm/mach-versal-net/cpu.c                |   8 +-
>   arch/arm/mach-versal/cpu.c                    |  16 +--
>   arch/arm/mach-versal2/cpu.c                   |   7 +-
>   arch/arm/mach-zynqmp/cpu.c                    |   8 +-
>   arch/mips/mach-octeon/dram.c                  |   4 +-
>   arch/riscv/cpu/k1/dram.c                      |  12 +-
>   arch/sandbox/cpu/spl.c                        |   4 +-
>   arch/x86/cpu/coreboot/sdram.c                 |   4 +-
>   arch/x86/cpu/efi/payload.c                    |   4 +-
>   arch/x86/cpu/efi/sdram.c                      |   4 +-
>   arch/x86/cpu/intel_common/mrc.c               |   4 +-
>   arch/x86/cpu/ivybridge/sdram_nop.c            |   4 +-
>   arch/x86/cpu/qemu/dram.c                      |   8 +-
>   arch/x86/cpu/quark/dram.c                     |   4 +-
>   arch/x86/cpu/slimbootloader/sdram.c           |   4 +-
>   arch/x86/cpu/tangier/sdram.c                  |   4 +-
>   arch/x86/lib/bootm.c                          |   5 +-
>   arch/x86/lib/fsp/fsp_dram.c                   |  18 +--
>   board/CZ.NIC/turris_1x/turris_1x.c            |  42 +++----
>   board/armltd/corstone1000/corstone1000.c      |   4 +-
>   board/armltd/integrator/integrator.c          |   4 +-
>   board/armltd/total_compute/total_compute.c    |   6 +-
>   board/armltd/vexpress/vexpress_common.c       |   8 +-
>   board/atmel/common/video_display.c            |   2 +-
>   .../sam9x60_curiosity/sam9x60_curiosity.c     |   2 +-
>   .../sam9x75_curiosity/sam9x75_curiosity.c     |   2 +-
>   .../atmel/sama5d27_som1_ek/sama5d27_som1_ek.c |   2 +-
>   .../sama5d27_wlsom1_ek/sama5d27_wlsom1_ek.c   |   2 +-
>   .../sama5d29_curiosity/sama5d29_curiosity.c   |   2 +-
>   .../atmel/sama5d2_xplained/sama5d2_xplained.c |   2 +-
>   .../sama7d65_curiosity/sama7d65_curiosity.c   |   2 +-
>   .../sama7g54_curiosity/sama7g54_curiosity.c   |   2 +-
>   board/axiado/scm3005/scm3005.c                |   4 +-
>   board/broadcom/bcmns3/ns3.c                   |   4 +-
>   board/compulab/cm_fx6/cm_fx6.c                |  28 ++---
>   board/elgin/elgin_rv1108/elgin_rv1108.c       |   4 +-
>   board/esd/meesc/meesc.c                       |   4 +-
>   board/friendlyarm/nanopi2/board.c             |  10 +-
>   board/ge/mx53ppd/mx53ppd.c                    |   8 +-
>   board/hisilicon/hikey/hikey.c                 |  24 ++--
>   board/hisilicon/hikey960/hikey960.c           |   4 +-
>   board/hisilicon/poplar/poplar.c               |   4 +-
>   board/k+p/kp_imx53/kp_imx53.c                 |   4 +-
>   board/keymile/pg-wcom-ls102xa/ddr.c           |   4 +-
>   board/kontron/sl28/sl28.c                     |   4 +-
>   board/kontron/sl28/spl_atf.c                  |   6 +-
>   board/liebherr/btt/btt.c                      |   2 +-
>   board/menlo/m53menlo/m53menlo.c               |   8 +-
>   board/nuvoton/arbel_evb/arbel_evb.c           |  26 ++--
>   board/nxp/imxrt1020-evk/imxrt1020-evk.c       |   2 +-
>   board/nxp/imxrt1050-evk/imxrt1050-evk.c       |   2 +-
>   board/nxp/imxrt1170-evk/imxrt1170-evk.c       |   2 +-
>   board/nxp/ls1021aqds/ddr.c                    |   4 +-
>   board/nxp/ls1028a/ls1028a.c                   |  10 +-
>   board/nxp/ls1043aqds/ls1043aqds.c             |   8 +-
>   board/nxp/ls1043ardb/ls1043ardb.c             |   8 +-
>   board/nxp/ls1046afrwy/ls1046afrwy.c           |   8 +-
>   board/nxp/ls1046aqds/ls1046aqds.c             |   8 +-
>   board/nxp/ls1046ardb/ls1046ardb.c             |   8 +-
>   board/nxp/ls1088a/ls1088a.c                   |   6 +-
>   board/nxp/ls2080aqds/ls2080aqds.c             |  14 +--
>   board/nxp/ls2080ardb/ls2080ardb.c             |  14 +--
>   board/nxp/lx2160a/lx2160a.c                   |   6 +-
>   board/phytec/phycore_am62x/phycore-am62x.c    |  26 ++--
>   board/phytec/phycore_am64x/phycore-am64x.c    |  18 +--
>   board/phytium/durian/durian.c                 |   4 +-
>   board/phytium/pe2201/pe2201.c                 |   4 +-
>   board/raspberrypi/rpi/rpi.c                   |  12 +-
>   board/renesas/common/rcar64-common.c          |   6 +-
>   board/renesas/genmai/genmai.c                 |   4 +-
>   board/renesas/sparrowhawk/sparrowhawk.c       |   8 +-
>   board/ronetix/pm9261/pm9261.c                 |   4 +-
>   board/ronetix/pm9263/pm9263.c                 |   4 +-
>   board/ronetix/pm9g45/pm9g45.c                 |   4 +-
>   board/samsung/arndale/arndale.c               |   4 +-
>   board/samsung/common/board.c                  |   6 +-
>   board/samsung/exynos-mobile/exynos-mobile.c   |   4 +-
>   board/samsung/goni/goni.c                     |  12 +-
>   board/samsung/smdkc100/smdkc100.c             |   4 +-
>   board/samsung/smdkv310/smdkv310.c             |  16 +--
>   board/siemens/iot2050/board.c                 |  16 +--
>   board/socionext/developerbox/developerbox.c   |   6 +-
>   board/st/stih410-b2260/board.c                |   4 +-
>   board/ste/stemmy/stemmy.c                     |   4 +-
>   board/ti/dra7xx/evm.c                         |   8 +-
>   board/ti/ks2_evm/board.c                      |   4 +-
>   board/toradex/colibri_imx7/colibri_imx7.c     |   8 +-
>   board/toradex/verdin-am62/verdin-am62.c       |   2 +-
>   board/toradex/verdin-am62p/verdin-am62p.c     |   2 +-
>   board/traverse/ten64/ten64.c                  |   6 +-
>   board/xilinx/zynq/cmds.c                      |   6 +-
>   board/xilinx/zynqmp/zynqmp.c                  |   4 +-
>   boot/image-board.c                            |   2 +-
>   boot/image-fdt.c                              |   4 +-
>   cmd/bdinfo.c                                  |  12 +-
>   cmd/ti/ddr4.c                                 |   8 +-
>   cmd/ufetch.c                                  |   4 +-
>   common/board_f.c                              |  71 ++++++++---
>   common/init/handoff.c                         |  10 +-
>   configs/qemu_arm64_defconfig                  |   1 +
>   doc/develop/memory.rst                        |   9 ++
>   drivers/bootcount/bootcount_ram.c             |   4 +-
>   drivers/ddr/altera/sdram_agilex.c             |   4 +-
>   drivers/ddr/altera/sdram_agilex5.c            |  18 +--
>   drivers/ddr/altera/sdram_agilex7m.c           |   4 +-
>   drivers/ddr/altera/sdram_arria10.c            |  12 +-
>   drivers/ddr/altera/sdram_n5x.c                |   4 +-
>   drivers/ddr/altera/sdram_s10.c                |   4 +-
>   drivers/ddr/altera/sdram_soc64.c              |  28 ++---
>   drivers/mmc/mvebu_mmc.c                       |   4 +-
>   drivers/net/mvgbe.c                           |   4 +-
>   drivers/pci/pci-uclass.c                      |   8 +-
>   drivers/usb/host/ehci-marvell.c               |   4 +-
>   drivers/video/meson/meson_vpu.c               |   8 +-
>   drivers/video/sunxi/sunxi_de2.c               |   2 +-
>   drivers/video/sunxi/sunxi_display.c           |   2 +-
>   include/asm-generic/global_data.h             |   7 ++
>   include/asm-generic/u-boot.h                  |   4 -
>   include/configs/m53menlo.h                    |   4 +-
>   include/configs/mx53cx9020.h                  |   4 +-
>   include/configs/mx53loco.h                    |   4 +-
>   include/configs/mx53ppd.h                     |   4 +-
>   include/fdtdec.h                              |   7 +-
>   include/init.h                                |   2 +-
>   lib/fdtdec.c                                  |  23 ++--
>   lib/lmb.c                                     |  19 ++-
>   test/cmd/bdinfo.c                             |   7 +-
>   170 files changed, 785 insertions(+), 728 deletions(-)
> 
> --
> 2.43.0
> 



More information about the U-Boot mailing list