ZynqMP ZCU102 SD-card Linux boot: EL2 cleanup, DTS bootargs, SDHCI init#750
ZynqMP ZCU102 SD-card Linux boot: EL2 cleanup, DTS bootargs, SDHCI init#750dgarske wants to merge 1 commit intowolfSSL:masterfrom
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Pull request overview
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Targets reliable SD-card Linux boot on Xilinx ZynqMP (ZCU102) by improving SDHCI init timing, adding timer support, patching DT bootargs at runtime, and ensuring ARM64 Linux entry requirements are met when booting from EL2.
Changes:
- Add SDHCI delays/retries to avoid CMD0 cold-boot timeout on Arasan SDHCI.
- Add ZynqMP timer + DTB
/chosen/bootargsruntime fixup to match wolfBoot partitioning. - Add EL2 cache clean + MMU/I/D-cache disable path before jumping to Linux.
Reviewed changes
Copilot reviewed 4 out of 4 changed files in this pull request and generated 11 comments.
| File | Description |
|---|---|
| src/sdhci.c | Adds settle delays and CMD0 retry loop to stabilize SD card initialization timing. |
| src/boot_aarch64_start.S | Introduces an EL2 cleanup/jump helper to satisfy Linux boot protocol cache/MMU requirements. |
| src/boot_aarch64.c | Calls the EL2 cleanup/jump helper when booting from EL2. |
| hal/zynq.c | Implements DTB bootargs fixup and adds a microsecond timer using the ARMv8 generic timer. |
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Fenrir Automated Review — PR #750
Scan targets checked: wolfboot-bugs, wolfboot-consttime, wolfboot-defaults, wolfboot-mutation, wolfboot-proptest, wolfboot-src, wolfboot-zeroize
Findings: 1
1 finding(s) posted as inline comments (see file-level comments below)
This review was generated automatically by Fenrir. Findings are non-blocking.
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Pull request overview
Copilot reviewed 6 out of 6 changed files in this pull request and generated 5 comments.
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Pull request overview
Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.
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dgarske
changed the title
Add the pieces needed to boot Linux end-to-end from the ZCU102 SD card
with wolfBoot at EL2:
* src/boot_aarch64_start.S: new el2_flush_and_disable_mmu helper that
cleans D-cache to PoC, invalidates I-cache to PoU, and clears
SCTLR_EL2.{M,C,I}, then returns. Satisfies the ARM64 Linux boot
protocol and is also correct for any other payload that sets up its
own translation (hypervisor, RTOS, later bootloader stage).
* src/boot_aarch64.c: call el2_flush_and_disable_mmu from do_boot() on
the EL2 direct-jump path before falling through to the br x4 block.
Also pull in hal/zynq.h and hal/nxp_ls1028a.h so the EL_HYPERVISOR /
BOOT_EL1 guards compile for those targets.
* hal/zynq.c: implement hal_dts_fixup() — set /chosen/bootargs from
LINUX_BOOTARGS (with a LINUX_BOOTARGS_ROOT default of /dev/mmcblk0p4)
and grow DTB totalsize by 512 bytes to give fdt_setprop() headroom
(matches hal/versal.c). Add hal_get_timer_us() via CNTPCT_EL0.
* src/sdhci.c: add a 1 ms settling delay after sdhci_platform_init()
and a CMD0 retry loop (up to 10 x 10 ms) so the ZCU102 Arasan
controller reliably detects the card after the slot-type change +
soft reset.
* config/examples/zynqmp_sdcard.config: stay at EL2 by default (comment
out BOOT_EL1), default rootfs to /dev/mmcblk0p4, turn DEBUG off.
* hal/versal.c: correct the default LINUX_BOOTARGS_ROOT to
/dev/mmcblk0p4 to match the shipped MBR layout.
* docs/Targets.md: note the unconditional EL2 cleanup in the ZynqMP
and Versal SD-card sections.
Behavior change: non-Linux AArch64 EL2 payloads now enter with MMU
off and caches clean instead of inheriting wolfBoot's tables. No
in-tree payload relies on the old state leakage.
ZynqMP ZCU102 SD-card Linux boot: EL2 cleanup, DTS bootargs, SDHCI init
Add the pieces needed to boot Linux end-to-end from the ZCU102 SD card
with wolfBoot at EL2:
cleans D-cache to PoC, invalidates I-cache to PoU, and clears
SCTLR_EL2.{M,C,I}, then returns. Satisfies the ARM64 Linux boot
protocol and is also correct for any other payload that sets up its
own translation (hypervisor, RTOS, later bootloader stage).
the EL2 direct-jump path before falling through to the br x4 block.
Also pull in hal/zynq.h and hal/nxp_ls1028a.h so the EL_HYPERVISOR /
BOOT_EL1 guards compile for those targets.
LINUX_BOOTARGS (with a LINUX_BOOTARGS_ROOT default of /dev/mmcblk0p4)
and grow DTB totalsize by 512 bytes to give fdt_setprop() headroom
(matches hal/versal.c). Add hal_get_timer_us() via CNTPCT_EL0.
and a CMD0 retry loop (up to 10 x 10 ms) so the ZCU102 Arasan
controller reliably detects the card after the slot-type change +
soft reset.
out BOOT_EL1), default rootfs to /dev/mmcblk0p4, turn DEBUG off.
/dev/mmcblk0p4 to match the shipped MBR layout.
and Versal SD-card sections.
Behavior change: non-Linux AArch64 EL2 payloads now enter with MMU
off and caches clean instead of inheriting wolfBoot's tables. No
in-tree payload relies on the old state leakage.