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2025-12-02boot/bootfdt: Add smbios3-entrypoint to FDT for non-EFI bootsAdriana Nicolae
The Linux kernel can discover SMBIOS tables through two primary methods: 1. Via EFI tables, when using EFI boot; 2. Via the 'smbios3-entrypoint' property in the /chosen node of the device tree. When U-Boot boots a Linux kernel using a non-EFI command ("bootm", "bootz", or "booti"), the kernel relies on the device tree to detect the hardware. If SMBIOS tables are available in U-Boot, they should be passed to the kernel via this device tree property. This patch modifies boot_fdt_prepare(), to inject the SMBIOSv3 table address into the device tree if there is a table generated by U-boot. The "board_fdt_chosen_smbios" is weak in order to leave the possibilty for specific boards to select custom SMBIOS addresses. The changes in this patch are added in the context of supporting this device tree property in linux kernel: https://lkml.org/lkml/2025/10/24/1393 Device tree schema was updated to include the "smbios3-entrypoint" node in pull request: https://github.com/devicetree-org/dt-schema/pull/177 Signed-off-by: Adriana Nicolae <[email protected]>
2025-10-03Revert "fdt: Make sure there is no stale initrd left"Sam Protsenko
This reverts commit 9fe2e4b46458f9c4ec6b8115ebf18b4b26fe6127. Commit 9fe2e4b46458 ("fdt: Make sure there is no stale initrd left") introduces a regression in case when U-Boot transfers control to an EFI app which acts as a subsequent bootloading program. Such an app might try to set "linux,initrd-start" and "linux,initrd-end" fdt properties, but by that time those properties are already removed by the code added in the mentioned commit. Particularly, the issue was observed on the E850-96 board where GBL EFI app [1] can't run Android successfully anymore. More specifically, the kernel can't see the ramdisk and panics with next messages: /dev/root: Can't open blockdev VFS: Cannot open root device "" or unknown-block(0,0): error -6 Please append a correct "root=" boot option; ... Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) fdt_initrd() function (where initrd dts properties are removed) is called two times: 1. First it's called by EFI boot manager (e.g. as a part of U-Boot Standard Boot mechanism) when it's installing FDT: fdt_initrd image_setup_libfdt efi_install_fdt efi_bootmgr_run efi_mgr_boot It's already enough for EFI app to malfunction. But then it's also called second time: 2. From the EFI app, via EFI DT fixup protocol: fdt_initrd image_setup_libfdt efi_dt_fixup struct efi_dt_fixup_protocol efi_dt_fixup_prot = { .fixup = efi_dt_fixup }; See [2] for specific GBL code which sets those fdt properties and then runs DT fixup protocol callback. This issue was discussed [3], but no action was taken since then. Revert this patch for now, until a proper solution can be found. [1] https://source.android.com/docs/core/architecture/bootloader/generic-bootloader/gbl-dev [2] https://android.googlesource.com/platform/bootable/libbootloader/+/refs/heads/gbl-mainline/gbl/libgbl/src/android_boot/mod.rs#208 [3] https://lists.denx.de/pipermail/u-boot/2025-July/593879.html Fixes: 9fe2e4b46458 ("fdt: Make sure there is no stale initrd left") Signed-off-by: Sam Protsenko <[email protected]>
2025-06-12fdt: Make sure there is no stale initrd leftRichard Weinberger
Although if we don't setup an initrd, there could be a stale initrd setting from the previous boot firmware in the live device tree. So, make sure there is no setting left if we don't want an initrd. This can happen when booting on a Raspberry Pi. The boot firmware can happily load an initrd before us and configuring the addresses in the live device tree we get handed over. Especially the setting `auto_initramfs` in config.txt is dangerous. When enabled (default), the firmware tries to be smart and looks for initramfs files. Signed-off-by: Richard Weinberger <[email protected]>
2025-03-26fdt: add support for adding pmem nodesMasahisa Kojima
One of the problems an OS may face, when running in EFI, is that a mounted ISO, after calling ExitBootServices goes away, if that ISO is resident in RAM memory as a ramdisk. ACPI has NFIT and NVDIMM support to provide ramdisks to the OS, but we don't have anything in place for DTs. Linux and device trees have support for persistent memory devices. So add a function that can inject a pmem node in a DT, so we can pass information on the ramdisk the OS. Signed-off-by: Masahisa Kojima <[email protected]> Signed-off-by: Sughosh Ganu <[email protected]> Reviewed-by: Ilias Apalodimas <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]>
2025-01-14common: fdt: hand over original fdt bootargs into board chosen handlerDmitry Rokosov
Sometimes, it is necessary to provide an additional bootargs string to the kernel command line. We have a real scenario where one U-Boot blob needs to boot several kernel images: the vendor-patched kernel image and the latest upstream kernel image. The Amlogic (Meson architecture) tty driver has different tty suffixes in these kernels: the vendor uses 'ttySx', while the upstream implementation uses 'ttyAMLx'. The initial console setup is provided to the kernel using the kernel command line (bootargs). For the vendor kernel, we should use 'console=ttyS0,115200', while for the upstream kernel, it must be 'console=ttyAML0,115200'. This means we have to use different command line strings depending on the kernel version. To resolve this issue, we cannot use the CMDLINE_EXTEND kernel configuration because it is considered legacy and is not supported for the arm64 architecture. CMDLINE_EXTEND is outdated primarily because we can provide additional command line strings through the 'chosen/bootargs' FDT node. However, U-Boot uses this node to inject the U-Boot bootargs environment variable content, which results in U-Boot silently overriding all data in the 'chosen/bootargs' node. While we do have the board_fdt_chosen_bootargs() board hook to address such issues, this function lacks any FDT context, such as the original value of the 'chosen/bootargs' node. This patch introduces a read-only (RO) fdt_property argument to board_fdt_chosen_bootargs() to share the original 'chosen/bootargs' data with the board code. Consequently, the board developer can decide how to handle this information for their board setup: whether to drop it or merge it with the bootargs environment. Signed-off-by: Dmitry Rokosov <[email protected]> Reviewed-by: Quentin Schulz <[email protected]>
2025-01-14fdt_support: board_fdt_chosen_bootargs() should return const char*Dmitry Rokosov
It should be structured this way to demonstrate to the caller that freeing the return value is unnecessary and that the caller cannot modify it. The function fdt_setprop() includes a parameter with a const char* prototype, so it is better to use the const qualifier. Signed-off-by: Dmitry Rokosov <[email protected]> Reviewed-by: Heinrich Schuchardt <[email protected]>
2024-06-28Merge patch series "automatically add /chosen/kaslr-seed and deduplicate code"Tom Rini
Tim Harvey <[email protected]> says: This series will automatically add /chosen/kaslr-seed to the dt if DM_RNG is enabled during the boot process. If RANDOMIZE_BASE is enabled in the Linux kernel instructing it to randomize the virtual address at which the kernel image is loaded, it expects entropy to be provided by the bootloader by populating /chosen/kaslr-seed with a 64-bit value from source of entropy at boot. If we have DM_RNG enabled populate this value automatically when fdt_chosen is called. We skip this if ARMV8_SEC_FIRMWARE_SUPPORT is enabled as its implementation uses a different source of entropy that is not yet implemented as DM_RNG. We also skip this if MEASURED_BOOT is enabled as in that case any modifications to the dt will cause measured boot to fail (although there are many other places the dt is altered). As this fdt node is added elsewhere create a library function and use it to deduplicate code. We will provide a parameter to overwrite the node if present. For our automatic injection, we will use the first rng device and not overwrite if already present with a non-zero value (which may have been populated by an earlier boot stage). This way if a board specific ft_board_setup() function wants to customize this behavior it can call fdt_kaslrseed with a rng device index of its choosing and set overwrite true. Note that the kalsrseed command (CMD_KASLRSEED) is likely pointless now but left in place in case boot scripts exist that rely on this command existing and returning success. An informational message is printed to alert users of this command that it is likely no longer needed. Note that the Kernel's EFI STUB only relies on EFI_RNG_PROTOCOL for randomization and completely ignores the kaslr-seed for its own randomness needs (i.e the randomization of the physical placement of the kernel). It gets weeded out from the DTB that gets handed over via efi_install_fdt() as it would also mess up the measured boot DTB TPM measurements as well.
2024-06-28fdt: automatically add /chosen/kaslr-seed if DM_RNG is enabledTim Harvey
If RANDOMIZE_BASE is enabled in the Linux kernel instructing it to randomize the virtual address at which the kernel image is loaded, it expects entropy to be provided by the bootloader by populating /chosen/kaslr-seed with a 64-bit value from source of entropy at boot. If we have DM_RNG enabled populate this value automatically when fdt_chosen is called. We skip this if ARMV8_SEC_FIRMWARE_SUPPORT is enabled as its implementation uses a different source of entropy that is not yet implemented as DM_RNG. We also skip this if MEASURED_BOOT is enabled as in that case any modifications to the dt will cause measured boot to fail (although there are many other places the dt is altered). Note that the Kernel's EFI STUB only relies on EFI_RNG_PROTOCOL for randomization and completely ignores the kaslr-seed for its own randomness needs (i.e the randomization of the physical placement of the kernel). It gets weeded out from the DTB that gets handed over via efi_install_fdt() as it would also mess up the measured boot DTB TPM measurements as well. Signed-off-by: Tim Harvey <[email protected]> Reviewed-by: Simon Glass <[email protected]> Cc: Michal Simek <[email protected]> Cc: Andy Yan <[email protected]> Cc: Akash Gajjar <[email protected]> Cc: Ilias Apalodimas <[email protected]> Cc: Simon Glass <[email protected]> Cc: Patrick Delaunay <[email protected]> Cc: Patrice Chotard <[email protected]> Cc: Devarsh Thakkar <[email protected]> Cc: Heinrich Schuchardt <[email protected]> Cc: Hugo Villeneuve <[email protected]> Cc: Marek Vasut <[email protected]> Cc: Tom Rini <[email protected]> Cc: Chris Morgan <[email protected]>
2024-06-28Add fdt_kaslrseed function to add kaslr-seed to chosen nodeTim Harvey
If RANDOMIZE_BASE is enabled in the Linux kernel instructing it to randomize the virtual address at which the kernel image is loaded, it expects entropy to be provided by the bootloader by populating /chosen/kaslr-seed with a 64-bit value from source of entropy at boot. Add a fdt_kaslrseed function to accommodate this allowing an existing node to be overwritten if present. For now use the first rng device but it would be good to enhance this in the future to allow some sort of selection or policy in choosing the rng device used. Signed-off-by: Tim Harvey <[email protected]> Reviewed-by: Simon Glass <[email protected]> Cc: Michal Simek <[email protected]> Cc: Andy Yan <[email protected]> Cc: Akash Gajjar <[email protected]> Cc: Ilias Apalodimas <[email protected]> Cc: Simon Glass <[email protected]> Cc: Patrick Delaunay <[email protected]> Cc: Patrice Chotard <[email protected]> Cc: Devarsh Thakkar <[email protected]> Cc: Heinrich Schuchardt <[email protected]> Cc: Hugo Villeneuve <[email protected]> Cc: Marek Vasut <[email protected]> Cc: Tom Rini <[email protected]> Cc: Chris Morgan <[email protected]> Reviewed-by: Caleb Connolly <[email protected]>
2024-05-20Restore patch series "arm: dts: am62-beagleplay: Fix Beagleplay Ethernet"Tom Rini
As part of bringing the master branch back in to next, we need to allow for all of these changes to exist here. Reported-by: Jonas Karlman <[email protected]> Signed-off-by: Tom Rini <[email protected]>
2024-05-19Revert "Merge patch series "arm: dts: am62-beagleplay: Fix Beagleplay Ethernet""Tom Rini
When bringing in the series 'arm: dts: am62-beagleplay: Fix Beagleplay Ethernet"' I failed to notice that b4 noticed it was based on next and so took that as the base commit and merged that part of next to master. This reverts commit c8ffd1356d42223cbb8c86280a083cc3c93e6426, reversing changes made to 2ee6f3a5f7550de3599faef9704e166e5dcace35. Reported-by: Jonas Karlman <[email protected]> Signed-off-by: Tom Rini <[email protected]>
2024-05-06boot: Remove <common.h> and add needed includesTom Rini
Remove <common.h> from all "boot/" files and when needed add missing include files directly. Signed-off-by: Tom Rini <[email protected]>
2024-04-21boot: Move framebuffer reservation to separate helperDevarsh Thakkar
Create separate helper for just reserving framebuffer region without creating or enabling simple-framebuffer node. This is useful for scenarios where user want to preserve the bootloader splash screen till OS boots up and display server gets started without displaying anything else in between and thus not requiring simple-framebuffer. Signed-off-by: Devarsh Thakkar <[email protected]> Reviewed-by: Nikhil M Jain <[email protected]>
2024-04-12fdt: Fix fdt_pack_reg() on 64-bit platformsSam Protsenko
When "memory" node is being processed in fdt_pack_reg() on ARM64 platforms, an unaligned bus access might happen, which leads to "synchronous abort" CPU exception. Consider next dts example: / { #address-cells = <2>; #size-cells = <1>; memory@80000000 { device_type = "memory"; reg = <0x0 0x80000000 0x3ab00000>, <0x0 0xc0000000 0x40000000>, <0x8 0x80000000 0x80000000>; }; }; After fdt_pack_reg() reads the first addr/size entry from such memory node, the "p" pointer becomes 12 bytes shifted from its original value (8 bytes for two address cells + 4 bytes for one size cell). So now it's not 64-bit aligned, and an attempt to do 64-bit bus access to that address will cause an abort like this: "Synchronous Abort" handler, esr 0x96000021, far 0xba235efc This issue was originally reported by David Virag [1] who observed it happening on Samsung Exynos7885 SoC (ARM64), and later the same issue was observed on Samsung Exynos850 (ARM64). Fix the issue by using put_unaligned_be64() helper, which takes care of possible unaligned 64-bit accesses. That solution was proposed by Simon Glass in the original thread [1]. [1] https://lists.denx.de/pipermail/u-boot/2023-July/522074.html Fixes: 739a01ed8e02 ("fdt_support: fix an endian bug of fdt_fixup_memory_banks") Suggested-by: Simon Glass <[email protected]> Reported-by: David Virag <[email protected]> Closes: https://lists.denx.de/pipermail/u-boot/2023-July/522074.html Signed-off-by: Sam Protsenko <[email protected]> Reviewed-by: Heinrich Schuchardt <[email protected]>
2023-12-13fdt: Improve the comment for fdt_shrink_to_minimum()Simon Glass
Add a bit more detail about what this function does. Signed-off-by: Simon Glass <[email protected]>
2023-11-10boot: Fix syntax in fdt_overlay_apply_verbose() error messageHugo Villeneuve
Remove superfluous "did". Signed-off-by: Hugo Villeneuve <[email protected]>
2023-09-19boot: Move fdt_support to boot/Simon Glass
This relates to booting since it fixes up the devicetree for the OS. Move it into the boot/ directory. Signed-off-by: Simon Glass <[email protected]> Reviewed-by: Tom Rini <[email protected]>