From 6c4a2f6329f0925161a80d2fd90aa8438c1ca82f Mon Sep 17 00:00:00 2001 From: Frederik Haxel Date: Tue, 12 Dec 2023 14:01:14 +0100 Subject: [PATCH] riscv: Allow disabling of BUILTIN_DTB for XIP This enables, among other things, testing with the QEMU virt machine. To build an XIP kernel for the QEMU virt machine, configure the the kernel as desired and apply the following configuration ``` CONFIG_NONPORTABLE=y CONFIG_XIP_KERNEL=y CONFIG_XIP_PHYS_ADDR=0x20000000 CONFIG_PHYS_RAM_BASE=0x80200000 CONFIG_BUILTIN_DTB=n ``` Since the QEMU virt flash memory expects a 32 MB file, the built image must be padded. For example, with `truncate -s 32M arch/riscv/boot/xipImage` The kernel can be started using the following command in QEMU (v8+) ``` qemu-system-riscv64 -M virt,pflash0=pflash0 \ -blockdev node-name=pflash0,driver=file,read-only=on,\ filename=arch/riscv/boot/xipImage ``` Signed-off-by: Frederik Haxel Link: https://lore.kernel.org/r/20231212130116.848530-4-haxel@fzi.de Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 6 +++--- arch/riscv/kernel/head.S | 4 +++- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 95a2a06acc6a6..72bc31b6eeb95 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -904,13 +904,13 @@ config RISCV_ISA_FALLBACK on the replacement properties, "riscv,isa-base" and "riscv,isa-extensions". -endmenu # "Boot options" - config BUILTIN_DTB - bool + bool "Built-in device tree" depends on OF && NONPORTABLE default y if XIP_KERNEL +endmenu # "Boot options" + config PORTABLE bool default !NONPORTABLE diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index a2e2f0dd3899a..a8939558702cb 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -266,10 +266,12 @@ SYM_CODE_START(_start_kernel) la sp, _end + THREAD_SIZE XIP_FIXUP_OFFSET sp mv s0, a0 + mv s1, a1 call __copy_data - /* Restore a0 copy */ + /* Restore a0 & a1 copy */ mv a0, s0 + mv a1, s1 #endif #ifndef CONFIG_XIP_KERNEL -- 2.30.2