riscv: Add EFI application infrastructure

The hello world binary and a few selftests require to build EFI target
binaries, not just the EFI host environment.

This patch adds all required files to generate an EFI binary for
RISC-V.

Signed-off-by: Alexander Graf <agraf@suse.de>

6 files changed, 405 insertions, 0 deletions

diff --git a/arch/riscv/config.mk b/arch/riscv/config.mk
index f65ed87..219e666 100644
--- a/arch/riscv/config.mk
+++ b/arch/riscv/config.mk
@@ -19,10 +19,12 @@ endif
 
 ifdef CONFIG_32BIT
 PLATFORM_LDFLAGS	+= -m $(32bit-emul)
+EFI_LDS			:= elf_riscv32_efi.lds
 endif
 
 ifdef CONFIG_64BIT
 PLATFORM_LDFLAGS	+= -m $(64bit-emul)
+EFI_LDS			:= elf_riscv64_efi.lds
 endif
 
 CONFIG_STANDALONE_LOAD_ADDR = 0x00000000 \
@@ -31,3 +33,6 @@ CONFIG_STANDALONE_LOAD_ADDR = 0x00000000 \
 PLATFORM_CPPFLAGS	+= -ffixed-gp -fpic
 PLATFORM_RELFLAGS += -fno-strict-aliasing -fno-common -gdwarf-2 -ffunction-sections
 LDFLAGS_u-boot += --gc-sections -static -pie
+
+EFI_CRT0		:= crt0_riscv_efi.o
+EFI_RELOC		:= reloc_riscv_efi.o
diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index 2eafd71..cc562f9 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -11,3 +11,14 @@ obj-$(CONFIG_CMD_GO) += boot.o
 obj-y	+= cache.o
 obj-y	+= interrupts.o
 obj-y   += setjmp.o
+
+# For building EFI apps
+CFLAGS_$(EFI_CRT0) := $(CFLAGS_EFI)
+CFLAGS_REMOVE_$(EFI_CRT0) := $(CFLAGS_NON_EFI)
+
+CFLAGS_$(EFI_RELOC) := $(CFLAGS_EFI)
+CFLAGS_REMOVE_$(EFI_RELOC) := $(CFLAGS_NON_EFI)
+
+extra-$(CONFIG_CMD_BOOTEFI_HELLO_COMPILE) += $(EFI_CRT0) $(EFI_RELOC)
+extra-$(CONFIG_CMD_BOOTEFI_SELFTEST) += $(EFI_CRT0) $(EFI_RELOC)
+extra-$(CONFIG_EFI) += $(EFI_CRT0) $(EFI_RELOC)
diff --git a/arch/riscv/lib/crt0_riscv_efi.S b/arch/riscv/lib/crt0_riscv_efi.S
new file mode 100644
index 0000000..498870e
--- /dev/null
+++ b/arch/riscv/lib/crt0_riscv_efi.S
@@ -0,0 +1,152 @@
+/*
+ * crt0-efi-riscv.S - PE/COFF header for RISC-V EFI applications
+ *
+ * Copright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
+ * Copright (C) 2018 Alexander Graf <agraf@suse.de>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+     BSD-2-Clause
+ *
+ * This file is inspired by arch/arm/lib/crt0_aarch64_efi.S
+ */
+
+#include <asm-generic/pe.h>
+
+#if __riscv_xlen == 64
+#define SIZE_LONG	8
+#define SAVE_LONG(reg, idx)	sd	reg, (idx*SIZE_LONG)(sp)
+#define LOAD_LONG(reg, idx)	ld	reg, (idx*SIZE_LONG)(sp)
+#define PE_MACHINE	0x5064
+#else
+#define SIZE_LONG	4
+#define SAVE_LONG(reg, idx)	sw	reg, (idx*SIZE_LONG)(sp)
+#define LOAD_LONG(reg, idx)	lw	reg, (idx*SIZE_LONG)(sp)
+#define PE_MACHINE	0x5032
+#endif
+
+
+	.section	.text.head
+
+	/*
+	 * Magic "MZ" signature for PE/COFF
+	 */
+	.globl	ImageBase
+ImageBase:
+	.ascii	"MZ"
+	.skip	58				/* 'MZ' + pad + offset == 64 */
+	.long	pe_header - ImageBase		/* Offset to the PE header */
+pe_header:
+	.ascii	"PE"
+	.short	0
+coff_header:
+	.short	PE_MACHINE			/* RISC-V 64/32-bit */
+	.short	2				/* nr_sections */
+	.long	0				/* TimeDateStamp */
+	.long	0				/* PointerToSymbolTable */
+	.long	1				/* NumberOfSymbols */
+	.short	section_table - optional_header	/* SizeOfOptionalHeader */
+	/*
+	 * Characteristics: IMAGE_FILE_DEBUG_STRIPPED |
+	 * IMAGE_FILE_EXECUTABLE_IMAGE | IMAGE_FILE_LINE_NUMS_STRIPPED
+	 */
+	.short	0x206
+optional_header:
+	.short	0x20b				/* PE32+ format */
+	.byte	0x02				/* MajorLinkerVersion */
+	.byte	0x14				/* MinorLinkerVersion */
+	.long	_edata - _start			/* SizeOfCode */
+	.long	0				/* SizeOfInitializedData */
+	.long	0				/* SizeOfUninitializedData */
+	.long	_start - ImageBase		/* AddressOfEntryPoint */
+	.long	_start - ImageBase		/* BaseOfCode */
+
+extra_header_fields:
+	.quad	0				/* ImageBase */
+	.long	0x20				/* SectionAlignment */
+	.long	0x8				/* FileAlignment */
+	.short	0				/* MajorOperatingSystemVersion */
+	.short	0				/* MinorOperatingSystemVersion */
+	.short	0				/* MajorImageVersion */
+	.short	0				/* MinorImageVersion */
+	.short	0				/* MajorSubsystemVersion */
+	.short	0				/* MinorSubsystemVersion */
+	.long	0				/* Win32VersionValue */
+
+	.long	_edata - ImageBase		/* SizeOfImage */
+
+	/*
+	 * Everything before the kernel image is considered part of the header
+	 */
+	.long	_start - ImageBase		/* SizeOfHeaders */
+	.long	0				/* CheckSum */
+	.short	IMAGE_SUBSYSTEM_EFI_APPLICATION /* Subsystem */
+	.short	0				/* DllCharacteristics */
+	.quad	0				/* SizeOfStackReserve */
+	.quad	0				/* SizeOfStackCommit */
+	.quad	0				/* SizeOfHeapReserve */
+	.quad	0				/* SizeOfHeapCommit */
+	.long	0				/* LoaderFlags */
+	.long	0x6				/* NumberOfRvaAndSizes */
+
+	.quad	0				/* ExportTable */
+	.quad	0				/* ImportTable */
+	.quad	0				/* ResourceTable */
+	.quad	0				/* ExceptionTable */
+	.quad	0				/* CertificationTable */
+	.quad	0				/* BaseRelocationTable */
+
+	/* Section table */
+section_table:
+
+	/*
+	 * The EFI application loader requires a relocation section
+	 * because EFI applications must be relocatable.  This is a
+	 * dummy section as far as we are concerned.
+	 */
+	.ascii	".reloc"
+	.byte	0
+	.byte	0			/* end of 0 padding of section name */
+	.long	0
+	.long	0
+	.long	0			/* SizeOfRawData */
+	.long	0			/* PointerToRawData */
+	.long	0			/* PointerToRelocations */
+	.long	0			/* PointerToLineNumbers */
+	.short	0			/* NumberOfRelocations */
+	.short	0			/* NumberOfLineNumbers */
+	.long	0x42100040		/* Characteristics (section flags) */
+
+
+	.ascii	".text"
+	.byte	0
+	.byte	0
+	.byte	0			/* end of 0 padding of section name */
+	.long	_edata - _start		/* VirtualSize */
+	.long	_start - ImageBase	/* VirtualAddress */
+	.long	_edata - _start		/* SizeOfRawData */
+	.long	_start - ImageBase	/* PointerToRawData */
+
+	.long	0		/* PointerToRelocations (0 for executables) */
+	.long	0		/* PointerToLineNumbers (0 for executables) */
+	.short	0		/* NumberOfRelocations  (0 for executables) */
+	.short	0		/* NumberOfLineNumbers  (0 for executables) */
+	.long	0xe0500020	/* Characteristics (section flags) */
+
+_start:
+	addi		sp, sp, -(SIZE_LONG * 3)
+	SAVE_LONG(a0, 0)
+	SAVE_LONG(a1, 1)
+	SAVE_LONG(ra, 2)
+
+	lla		a0, ImageBase
+	lla		a1, _DYNAMIC
+	call		_relocate
+	bne		a0, zero, 0f
+
+	LOAD_LONG(a1, 1)
+	LOAD_LONG(a0, 0)
+	call		efi_main
+
+	LOAD_LONG(ra, 2)
+
+0:	addi		sp, sp, (SIZE_LONG * 3)
+	ret
diff --git a/arch/riscv/lib/elf_riscv32_efi.lds b/arch/riscv/lib/elf_riscv32_efi.lds
new file mode 100644
index 0000000..96d1198
--- /dev/null
+++ b/arch/riscv/lib/elf_riscv32_efi.lds
@@ -0,0 +1,70 @@
+/*
+ * U-Boot riscv32 EFI linker script
+ *
+ * SPDX-License-Identifier:	BSD-2-Clause
+ *
+ * Modified from arch/arm/lib/elf_aarch64_efi.lds
+ */
+
+OUTPUT_FORMAT("elf32-littleriscv", "elf32-littleriscv", "elf32-littleriscv")
+OUTPUT_ARCH(riscv)
+ENTRY(_start)
+SECTIONS
+{
+	.text 0x0 : {
+		_text = .;
+		*(.text.head)
+		*(.text)
+		*(.text.*)
+		*(.gnu.linkonce.t.*)
+		*(.srodata)
+		*(.rodata*)
+		. = ALIGN(16);
+	}
+	_etext = .;
+	_text_size = . - _text;
+	.dynamic  : { *(.dynamic) }
+	.data : {
+		_data = .;
+		*(.sdata)
+		*(.data)
+		*(.data1)
+		*(.data.*)
+		*(.got.plt)
+		*(.got)
+
+		/*
+		 * The EFI loader doesn't seem to like a .bss section, so we
+		 * stick it all into .data:
+		 */
+		. = ALIGN(16);
+		_bss = .;
+		*(.sbss)
+		*(.scommon)
+		*(.dynbss)
+		*(.bss)
+		*(.bss.*)
+		*(COMMON)
+		. = ALIGN(16);
+		_bss_end = .;
+		_edata = .;
+	}
+	.rela.dyn : { *(.rela.dyn) }
+	.rela.plt : { *(.rela.plt) }
+	.rela.got : { *(.rela.got) }
+	.rela.data : { *(.rela.data) *(.rela.data*) }
+	_data_size = . - _etext;
+
+	. = ALIGN(4096);
+	.dynsym   : { *(.dynsym) }
+	. = ALIGN(4096);
+	.dynstr   : { *(.dynstr) }
+	. = ALIGN(4096);
+	.note.gnu.build-id : { *(.note.gnu.build-id) }
+	/DISCARD/ : {
+		*(.rel.reloc)
+		*(.eh_frame)
+		*(.note.GNU-stack)
+	}
+	.comment 0 : { *(.comment) }
+}
diff --git a/arch/riscv/lib/elf_riscv64_efi.lds b/arch/riscv/lib/elf_riscv64_efi.lds
new file mode 100644
index 0000000..25c863d
--- /dev/null
+++ b/arch/riscv/lib/elf_riscv64_efi.lds
@@ -0,0 +1,70 @@
+/*
+ * U-Boot riscv64 EFI linker script
+ *
+ * SPDX-License-Identifier:	BSD-2-Clause
+ *
+ * Modified from arch/arm/lib/elf_aarch64_efi.lds
+ */
+
+OUTPUT_FORMAT("elf64-littleriscv", "elf64-littleriscv", "elf64-littleriscv")
+OUTPUT_ARCH(riscv)
+ENTRY(_start)
+SECTIONS
+{
+	.text 0x0 : {
+		_text = .;
+		*(.text.head)
+		*(.text)
+		*(.text.*)
+		*(.gnu.linkonce.t.*)
+		*(.srodata)
+		*(.rodata*)
+		. = ALIGN(16);
+	}
+	_etext = .;
+	_text_size = . - _text;
+	.dynamic  : { *(.dynamic) }
+	.data : {
+		_data = .;
+		*(.sdata)
+		*(.data)
+		*(.data1)
+		*(.data.*)
+		*(.got.plt)
+		*(.got)
+
+		/*
+		 * The EFI loader doesn't seem to like a .bss section, so we
+		 * stick it all into .data:
+		 */
+		. = ALIGN(16);
+		_bss = .;
+		*(.sbss)
+		*(.scommon)
+		*(.dynbss)
+		*(.bss)
+		*(.bss.*)
+		*(COMMON)
+		. = ALIGN(16);
+		_bss_end = .;
+		_edata = .;
+	}
+	.rela.dyn : { *(.rela.dyn) }
+	.rela.plt : { *(.rela.plt) }
+	.rela.got : { *(.rela.got) }
+	.rela.data : { *(.rela.data) *(.rela.data*) }
+	_data_size = . - _etext;
+
+	. = ALIGN(4096);
+	.dynsym   : { *(.dynsym) }
+	. = ALIGN(4096);
+	.dynstr   : { *(.dynstr) }
+	. = ALIGN(4096);
+	.note.gnu.build-id : { *(.note.gnu.build-id) }
+	/DISCARD/ : {
+		*(.rel.reloc)
+		*(.eh_frame)
+		*(.note.GNU-stack)
+	}
+	.comment 0 : { *(.comment) }
+}
diff --git a/arch/riscv/lib/reloc_riscv_efi.c b/arch/riscv/lib/reloc_riscv_efi.c
new file mode 100644
index 0000000..d80ffc9
--- /dev/null
+++ b/arch/riscv/lib/reloc_riscv_efi.c
@@ -0,0 +1,97 @@
+/* reloc_riscv.c - position independent ELF shared object relocator
+   Copyright (C) 2018 Alexander Graf <agraf@suse.de>
+   Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
+   Copyright (C) 1999 Hewlett-Packard Co.
+	Contributed by David Mosberger <davidm@hpl.hp.com>.
+
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials
+      provided with the distribution.
+    * Neither the name of Hewlett-Packard Co. nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+    CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+    INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+    MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+    BE LIABLE FOR ANYDIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
+    OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+    TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+    THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+*/
+
+#include <efi.h>
+
+#include <elf.h>
+
+#if __riscv_xlen == 64
+#define Elf_Dyn		Elf64_Dyn
+#define Elf_Rela	Elf64_Rela
+#define ELF_R_TYPE	ELF64_R_TYPE
+#else
+#define Elf_Dyn		Elf32_Dyn
+#define Elf_Rela	Elf32_Rela
+#define ELF_R_TYPE	ELF32_R_TYPE
+#endif
+
+efi_status_t _relocate(long ldbase, Elf_Dyn *dyn, efi_handle_t image,
+		       struct efi_system_table *systab)
+{
+	long relsz = 0, relent = 0;
+	Elf_Rela *rel = 0;
+	unsigned long *addr;
+	int i;
+
+	for (i = 0; dyn[i].d_tag != DT_NULL; ++i) {
+		switch (dyn[i].d_tag) {
+		case DT_RELA:
+			rel = (Elf_Rela *)((ulong)dyn[i].d_un.d_ptr + ldbase);
+			break;
+		case DT_RELASZ:
+			relsz = dyn[i].d_un.d_val;
+			break;
+		case DT_RELAENT:
+			relent = dyn[i].d_un.d_val;
+			break;
+		default:
+			break;
+		}
+	}
+
+	if (!rel && relent == 0)
+		return EFI_SUCCESS;
+
+	if (!rel || relent == 0)
+		return EFI_LOAD_ERROR;
+
+	while (relsz > 0) {
+		/* apply the relocs */
+		switch (ELF_R_TYPE(rel->r_info)) {
+		case R_RISCV_RELATIVE:
+			addr = (ulong *)(ldbase + rel->r_offset);
+			*addr = ldbase + rel->r_addend;
+			break;
+		default:
+			/* Panic */
+			while (1) ;
+		}
+		rel = (Elf_Rela *)((char *)rel + relent);
+		relsz -= relent;
+	}
+	return EFI_SUCCESS;
+}