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🟡 Changes recommended
Two-cell addresses truncate unsafely on 32-bit builds, and the central loader-level initrd regression lacks direct coverage.
Review effort: Balanced
Findings: 1
Open (4)
What changed in this PR
Adds support for booting kernel-only FIT images without kernel load/entry addresses or an embedded device tree.
Changes:
- Adds configurable FIT kernel relocation and 64-bit address handling.
- Defers initrd fixups until the final DTB is selected.
- Adds Versal high-DDR configuration, documentation, CI, and tests.
| File | Description |
|---|---|
src/fdt.c |
Adds kernel relocation helper and diagnostics. |
src/update_ram.c |
Adds DTB fallback and deferred initrd fixup. |
src/update_disk.c |
Defers initrd fixup and improves address logging. |
src/boot_aarch64.c |
Prints full-width boot addresses. |
include/fdt.h |
Declares the kernel-loading API. |
include/target.h.in |
Exposes the kernel load address. |
Makefile |
Generates the new target setting. |
options.mk |
Defines the kernel relocation option. |
tools/config.mk |
Persists the new configuration variable. |
tools/unit-tests/Makefile |
Enables ramdisk testing. |
tools/unit-tests/unit-fit-gzip.c |
Tests relocation and initrd helpers. |
tools/unit-tests/unit-fdt.c |
Tests two-cell FIT addresses. |
tools/unit-tests/unit-update-disk-fit.c |
Adds the kernel loader stub. |
docs/Targets.md |
Documents supported FIT layouts. |
config/examples/versal_vmk180.config |
Documents optional relocation settings. |
config/examples/versal_vmk180_highddr.config |
Adds a high-DDR Versal example. |
.github/workflows/test-configs.yml |
Builds the new example in CI. |
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Description
A Versal customer FIT built without
load/entryon the kernel node and with nofdtsub-image exposed four problems.No device tree. A kernel-only FIT left
dts_addrNULL anddo_boot()passed that to the kernel.update_ram.chad its configured-DTB fallback in theelseof the FIT branch;update_disk.chad none beyondhal_get_boot_dts(), a weak NULL onlyhal/cm4.cimplements. Both now fall back whenever the FIT yields no device tree, validating the blob and relocating it into the staging window first.No initrd.
fit_load_ramdisk()ran inside the FIT branch against a tree the FIT supplied, so a device tree from the boot firmware never received/chosen/linux,initrd-*. Both loaders defer the fixup until the source is settled, and a ramdisk staged with no tree to name it in is now reported instead of skipped silently.Truncated addresses.
fdt_getprop_address()cast an 8-byteload/entrydown touintptr_t; it now rejects a value the target cannot represent.Wrong exception level.
hal/versal.hdefaulted toBOOT_EL1, dropping only the boot core to EL1 while PSCI brings the secondaries up at EL2 - Linux refuses that withCPUs started in inconsistent modes. The default is nowBOOT_EL2, matching Xilinx U-Boot;BOOT_EL1=1still works but must be stated explicitly.WOLFBOOT_LOAD_KERNEL_ADDRESSstages the FIT kernel at a configured address, mirroring the ramdisk and fpga options, with0honoring the FIT.DDR_HIGH_BASE/DDR_HIGH_SIZE/NO_DDR_LOWreplace theVERSAL_DDR_HIGH_*defines with AArch64-generic ones; the old spellings are still accepted, an incomplete combination is a build error rather than a silently unmapped window, and these and the exception-level options now survive amake config.Testing
Validated on a Versal VMK180: the FIT boots with the device tree from the BIF raw partition, and the exception-level change was confirmed by reading Linux's
__boot_cpu_modeover JTAG with onlyBOOT.BINdiffering between runs. Hosted tests cover the kernel-only-FIT fallback, the initrd ordering and its failure path on both loaders, and a second build of the FDT suite with the pointer bound narrowed to 32 bits exercises the two-cell rejection on a 64-bit host.The disk loader has no DTB-digest machinery, so a device tree supplied from outside the FIT is unauthenticated there and
LINUX_BOOTARGSalways supplies the command line;docs/Targets.mdstates this, and anfdtsub-image is the way to bring such a tree inside the root of trust. VA-cleaning the actual FIT load destinations before the handoff is left as follow-on work.