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authorAtish Patra <atish.patra@wdc.com>2020-09-18 01:37:14 +0300
committerPalmer Dabbelt <palmerdabbelt@google.com>2020-10-03 00:31:21 +0300
commitd7071743db31b4f6898b1c742e4b451bb4bc4b02 (patch)
treea1200c6aee002dd0b0658316660cc2ac0b1a6c3b /arch/riscv
parentcb7d2dd5612a77a2597c00fce770a52c921e2ea5 (diff)
downloadlinux-d7071743db31b4f6898b1c742e4b451bb4bc4b02.tar.xz
RISC-V: Add EFI stub support.
Add a RISC-V architecture specific stub code that actually copies the actual kernel image to a valid address and jump to it after boot services are terminated. Enable UEFI related kernel configs as well for RISC-V. Signed-off-by: Atish Patra <atish.patra@wdc.com> Link: https://lore.kernel.org/r/20200421033336.9663-4-atish.patra@wdc.com [ardb: - move hartid fetch into check_platform_features() - use image_size not reserve_size - select ISA_C - do not use dram_base] Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch/riscv')
-rw-r--r--arch/riscv/Kconfig22
-rw-r--r--arch/riscv/Makefile1
-rw-r--r--arch/riscv/configs/defconfig1
-rw-r--r--arch/riscv/include/asm/efi.h35
4 files changed, 59 insertions, 0 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5e4ace64acbc..6ef2394be857 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -401,6 +401,26 @@ config CMDLINE_FORCE
endchoice
+config EFI_STUB
+ bool
+
+config EFI
+ bool "UEFI runtime support"
+ depends on OF
+ select LIBFDT
+ select UCS2_STRING
+ select EFI_PARAMS_FROM_FDT
+ select EFI_STUB
+ select EFI_GENERIC_STUB
+ select RISCV_ISA_C
+ default y
+ help
+ This option provides support for runtime services provided
+ by UEFI firmware (such as non-volatile variables, realtime
+ clock, and platform reset). A UEFI stub is also provided to
+ allow the kernel to be booted as an EFI application. This
+ is only useful on systems that have UEFI firmware.
+
endmenu
config BUILTIN_DTB
@@ -413,3 +433,5 @@ menu "Power management options"
source "kernel/power/Kconfig"
endmenu
+
+source "drivers/firmware/Kconfig"
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index fb6e37db836d..10df59f28add 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -80,6 +80,7 @@ head-y := arch/riscv/kernel/head.o
core-y += arch/riscv/
libs-y += arch/riscv/lib/
+libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
PHONY += vdso_install
vdso_install:
diff --git a/arch/riscv/configs/defconfig b/arch/riscv/configs/defconfig
index d58c93efb603..d222d353d86d 100644
--- a/arch/riscv/configs/defconfig
+++ b/arch/riscv/configs/defconfig
@@ -130,3 +130,4 @@ CONFIG_DEBUG_BLOCK_EXT_DEVT=y
# CONFIG_RUNTIME_TESTING_MENU is not set
CONFIG_MEMTEST=y
# CONFIG_SYSFS_SYSCALL is not set
+CONFIG_EFI=y
diff --git a/arch/riscv/include/asm/efi.h b/arch/riscv/include/asm/efi.h
new file mode 100644
index 000000000000..bf6a40e20a8e
--- /dev/null
+++ b/arch/riscv/include/asm/efi.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ */
+#ifndef _ASM_EFI_H
+#define _ASM_EFI_H
+
+#include <asm/io.h>
+#include <asm/mmu_context.h>
+#include <asm/ptrace.h>
+#include <asm/tlbflush.h>
+
+/* on RISC-V, the FDT may be located anywhere in system RAM */
+static inline unsigned long efi_get_max_fdt_addr(unsigned long image_addr)
+{
+ return ULONG_MAX;
+}
+
+/* Load initrd at enough distance from DRAM start */
+static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
+{
+ return image_addr + SZ_256M;
+}
+
+#define alloc_screen_info(x...) (&screen_info)
+
+static inline void free_screen_info(struct screen_info *si)
+{
+}
+
+static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
+{
+}
+
+#endif /* _ASM_EFI_H */