@@ -2061,6 +2061,25 @@ config AUTO_ZRELADDR
0xf8000000. This assumes the zImage being placed in the first 128MB
from start of memory.
+config EFI_STUB
+ bool
+
+config EFI
+ bool "UEFI runtime support"
+ depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
+ select UCS2_STRING
+ select EFI_PARAMS_FROM_FDT
+ select EFI_STUB
+ select EFI_ARMSTUB
+ select EFI_RUNTIME_WRAPPERS
+ ---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 for kernels that may run on systems that have
+ UEFI firmware.
+
endmenu
menu "CPU Power Management"
@@ -167,9 +167,12 @@ if [ $(words $(ZRELADDR)) -gt 1 -a "$(CONFIG_AUTO_ZRELADDR)" = "" ]; then \
false; \
fi
+efi-obj-$(CONFIG_EFI_STUB) := $(obj)/efi-stub.o $(obj)/efi-banner.o \
+ $(objtree)/drivers/firmware/efi/libstub/lib.a
+
$(obj)/vmlinux: $(obj)/vmlinux.lds $(obj)/$(HEAD) $(obj)/piggy.$(suffix_y).o \
$(addprefix $(obj)/, $(OBJS)) $(lib1funcs) $(ashldi3) \
- $(bswapsdi2) FORCE
+ $(bswapsdi2) $(efi-obj-y) FORCE
@$(check_for_multiple_zreladdr)
$(call if_changed,ld)
@$(check_for_bad_syms)
new file mode 100644
@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) 2013-2015 Linaro Ltd
+ * Authors: Roy Franz <roy.franz@linaro.org>
+ * Ard Biesheuvel <ard.biesheuvel@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+ .macro __nop
+#ifdef CONFIG_EFI_STUB
+ @ This is almost but not quite a NOP, since it does clobber the
+ @ condition flags. But it is the best we can do for EFI, since
+ @ PE/COFF expects the magic string "MZ" at offset 0, while the
+ @ ARM/Linux boot protocol expects an executable instruction
+ @ there.
+ .inst 'M' | ('Z' << 8) | (0x1310 << 16) @ tstne r0, #0x4d000
+#else
+ mov r0, r0
+#endif
+ .endm
+
+ .macro __EFI_HEADER
+#ifdef CONFIG_EFI_STUB
+ b __efi_start
+
+ .set start_offset, __efi_start - start
+ .org start + 0x3c
+ @
+ @ The PE header can be anywhere in the file, but for
+ @ simplicity we keep it together with the MSDOS header
+ @ The offset to the PE/COFF header needs to be at offset
+ @ 0x3C in the MSDOS header.
+ @ The only 2 fields of the MSDOS header that are used are this
+ @ PE/COFF offset, and the "MZ" bytes at offset 0x0.
+ @
+ .long pe_header - start @ Offset to the PE header.
+
+pe_header:
+ .ascii "PE\0\0"
+
+coff_header:
+ .short 0x01c2 @ ARM or Thumb
+ .short 2 @ nr_sections
+ .long 0 @ TimeDateStamp
+ .long 0 @ PointerToSymbolTable
+ .long 1 @ NumberOfSymbols
+ .short section_table - optional_header
+ @ SizeOfOptionalHeader
+ .short 0x306 @ Characteristics.
+ @ IMAGE_FILE_32BIT_MACHINE |
+ @ IMAGE_FILE_DEBUG_STRIPPED |
+ @ IMAGE_FILE_EXECUTABLE_IMAGE |
+ @ IMAGE_FILE_LINE_NUMS_STRIPPED
+
+optional_header:
+ .short 0x10b @ PE32 format
+ .byte 0x02 @ MajorLinkerVersion
+ .byte 0x14 @ MinorLinkerVersion
+ .long _end - __efi_start @ SizeOfCode
+ .long 0 @ SizeOfInitializedData
+ .long 0 @ SizeOfUninitializedData
+ .long efi_stub_entry - start @ AddressOfEntryPoint
+ .long start_offset @ BaseOfCode
+ .long 0 @ data
+
+extra_header_fields:
+ .long 0 @ ImageBase
+ .long 0x200 @ SectionAlignment
+ .long 0x200 @ FileAlignment
+ .short 0 @ MajorOperatingSystemVersion
+ .short 0 @ MinorOperatingSystemVersion
+ .short 0 @ MajorImageVersion
+ .short 0 @ MinorImageVersion
+ .short 0 @ MajorSubsystemVersion
+ .short 0 @ MinorSubsystemVersion
+ .long 0 @ Win32VersionValue
+
+ .long _end - start @ SizeOfImage
+ .long start_offset @ SizeOfHeaders
+ .long 0 @ CheckSum
+ .short 0xa @ Subsystem (EFI application)
+ .short 0 @ DllCharacteristics
+ .long 0 @ SizeOfStackReserve
+ .long 0 @ SizeOfStackCommit
+ .long 0 @ SizeOfHeapReserve
+ .long 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:
+ @
+ @ 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\0\0"
+ .long 0 @ VirtualSize
+ .long 0 @ VirtualAddress
+ .long 0 @ SizeOfRawData
+ .long 0 @ PointerToRawData
+ .long 0 @ PointerToRelocations
+ .long 0 @ PointerToLineNumbers
+ .short 0 @ NumberOfRelocations
+ .short 0 @ NumberOfLineNumbers
+ .long 0x42100040 @ Characteristics
+
+ .ascii ".text\0\0\0"
+ .long _end - __efi_start @ VirtualSize
+ .long __efi_start @ VirtualAddress
+ .long _edata - __efi_start @ SizeOfRawData
+ .long __efi_start @ PointerToRawData
+ .long 0 @ PointerToRelocations
+ .long 0 @ PointerToLineNumbers
+ .short 0 @ NumberOfRelocations
+ .short 0 @ NumberOfLineNumbers
+ .long 0xe0500020 @ Characteristics
+
+ .align 9
+__efi_start:
+#endif
+ .endm
new file mode 100644
@@ -0,0 +1,89 @@
+/*
+ * linux/arch/arm/boot/compressed/efi-stub.c
+ *
+ * Copyright (C) 2013 Linaro Ltd; <roy.franz@linaro.org>
+ *
+ * This file implements the EFI boot stub for the ARM kernel
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/efi.h>
+#include <asm/efi.h>
+
+efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
+ unsigned long *image_addr,
+ unsigned long *image_size,
+ unsigned long *reserve_addr,
+ unsigned long *reserve_size,
+ unsigned long dram_base,
+ efi_loaded_image_t *image)
+{
+ unsigned long nr_pages;
+ efi_status_t status;
+ /* Use alloc_addr to tranlsate between types */
+ efi_physical_addr_t alloc_addr;
+
+ /*
+ * Verify that the DRAM base address is compatible with the ARM
+ * boot protocol, which determines the base of DRAM by masking
+ * off the low 27 bits of the address at which the zImage is
+ * loaded. These assumptions are made by the decompressor,
+ * before any memory map is available.
+ */
+ dram_base = round_up(dram_base, SZ_128M);
+
+ /*
+ * Reserve memory for the uncompressed kernel image. This is
+ * all that prevents any future allocations from conflicting
+ * with the kernel. Since we can't tell from the compressed
+ * image how much DRAM the kernel actually uses (due to BSS
+ * size uncertainty) we allocate the maximum possible size.
+ * Do this very early, as prints can cause memory allocations
+ * that may conflict with this.
+ */
+ alloc_addr = dram_base;
+ *reserve_size = MAX_UNCOMP_KERNEL_SIZE;
+ nr_pages = round_up(*reserve_size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
+ status = sys_table->boottime->allocate_pages(EFI_ALLOCATE_ADDRESS,
+ EFI_LOADER_DATA,
+ nr_pages, &alloc_addr);
+ if (status != EFI_SUCCESS) {
+ *reserve_size = 0;
+ pr_efi_err(sys_table, "Unable to allocate memory for uncompressed kernel.\n");
+ return status;
+ }
+ *reserve_addr = alloc_addr;
+
+ /*
+ * Relocate the zImage, if required. ARM doesn't have a
+ * preferred address, so we set it to 0, as we want to allocate
+ * as low in memory as possible.
+ */
+ *image_size = image->image_size;
+ status = efi_relocate_kernel(sys_table, image_addr, *image_size,
+ *image_size, 0, 0);
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table, "Failed to relocate kernel.\n");
+ efi_free(sys_table, *reserve_size, *reserve_addr);
+ *reserve_size = 0;
+ return status;
+ }
+
+ /*
+ * Check to see if we were able to allocate memory low enough
+ * in memory. The kernel determines the base of DRAM from the
+ * address at which the zImage is loaded.
+ */
+ if (*image_addr + *image_size > dram_base + ZIMAGE_OFFSET_LIMIT) {
+ pr_efi_err(sys_table, "Failed to relocate kernel, no low memory available.\n");
+ efi_free(sys_table, *reserve_size, *reserve_addr);
+ *reserve_size = 0;
+ efi_free(sys_table, *image_size, *image_addr);
+ *image_size = 0;
+ return EFI_LOAD_ERROR;
+ }
+ return EFI_SUCCESS;
+}
@@ -12,6 +12,8 @@
#include <asm/assembler.h>
#include <asm/v7m.h>
+#include "efi-header.S"
+
AR_CLASS( .arch armv7-a )
M_CLASS( .arch armv7-m )
@@ -126,7 +128,7 @@
start:
.type start,#function
.rept 7
- mov r0, r0
+ __nop
.endr
ARM( mov r0, r0 )
ARM( b 1f )
@@ -139,7 +141,8 @@ start:
.word 0x04030201 @ endianness flag
THUMB( .thumb )
-1:
+1: __EFI_HEADER
+
ARM_BE8( setend be ) @ go BE8 if compiled for BE8
AR_CLASS( mrs r9, cpsr )
#ifdef CONFIG_ARM_VIRT_EXT
@@ -1353,6 +1356,53 @@ __enter_kernel:
reloc_code_end:
+#ifdef CONFIG_EFI_STUB
+ .align 2
+_start: .long start - .
+
+ENTRY(efi_stub_entry)
+ @ allocate space on stack for passing current zImage address
+ @ and for the EFI stub to return of new entry point of
+ @ zImage, as EFI stub may copy the kernel. Pointer address
+ @ is passed in r2. r0 and r1 are passed through from the
+ @ EFI firmware to efi_entry
+ adr ip, _start
+ ldr r3, [ip]
+ add r3, r3, ip
+ stmfd sp!, {r3, lr}
+ mov r2, sp @ pass zImage address in r2
+ bl efi_entry
+
+ @ Check for error return from EFI stub. r0 has FDT address
+ @ or error code.
+ cmn r0, #1
+ beq efi_load_fail
+
+ @ Preserve return value of efi_entry() in r4
+ mov r4, r0
+ bl cache_clean_flush
+ bl cache_off
+
+ @ Set parameters for booting zImage according to boot protocol
+ @ put FDT address in r2, it was returned by efi_entry()
+ @ r1 is the machine type, and r0 needs to be 0
+ mov r0, #0
+ mov r1, #0xFFFFFFFF
+ mov r2, r4
+
+ @ Branch to (possibly) relocated zImage that is in [sp]
+ ldr lr, [sp]
+ ldr ip, =start_offset
+ add lr, lr, ip
+ mov pc, lr @ no mode switch
+
+efi_load_fail:
+ @ Return EFI_LOAD_ERROR to EFI firmware on error.
+ ldr r0, =0x80000001
+ ldmfd sp!, {ip, pc}
+ENDPROC(efi_stub_entry)
+#endif
+
.align
.section ".stack", "aw", %nobits
.L_user_stack: .space 4096
@@ -48,6 +48,13 @@ SECTIONS
*(.rodata)
*(.rodata.*)
}
+ .data : {
+ /*
+ * The EFI stub always executes from RAM, and runs strictly before the
+ * decompressor, so we can make an exception for its r/w data, and keep it
+ */
+ *(.data.efistub)
+ }
.piggydata : {
*(.piggydata)
}
@@ -66,4 +66,27 @@ void efi_virtmap_unload(void);
#define efi_parse_fdt(x)
#endif /* CONFIG_EFI */
+/* arch specific definitions used by the stub code */
+
+#define efi_call_early(f, ...) sys_table_arg->boottime->f(__VA_ARGS__)
+
+/*
+ * A reasonable upper bound for the uncompressed kernel size is 32 MBytes,
+ * so we will reserve that amount of memory. We have no easy way to tell what
+ * the actuall size of code + data the uncompressed kernel will use.
+ * If this is insufficient, the decompressor will relocate itself out of the
+ * way before performing the decompression.
+ */
+#define MAX_UNCOMP_KERNEL_SIZE SZ_32M
+
+/*
+ * The kernel zImage should preferably be located between 32 MB and 128 MB
+ * from the base of DRAM. The min address leaves space for a maximal size
+ * uncompressed image, and the max address is due to how the zImage decompressor
+ * picks a destination address.
+ */
+#define ZIMAGE_OFFSET_LIMIT SZ_128M
+#define MIN_ZIMAGE_OFFSET MAX_UNCOMP_KERNEL_SIZE
+#define MAX_FDT_OFFSET ZIMAGE_OFFSET_LIMIT
+
#endif /* _ASM_ARM_EFI_H */
@@ -62,3 +62,15 @@ quiet_cmd_stubcopy = STUBCPY $@
$(OBJDUMP) -r $@ | grep R_AARCH64_ABS \
&& (echo >&2 "$@: absolute symbol references not allowed in the EFI stub"; \
rm -f $@; /bin/false); else /bin/false; fi
+
+#
+# ARM discards the .data section because it disallows r/w data in the
+# decompressor. So move our .data to .data.efistub, which is preserved
+# explicitly by the decompressor linker script.
+#
+extra-$(CONFIG_ARM) := $(lib-y)
+lib-$(CONFIG_ARM) := $(patsubst %.o,%.stub.o,$(lib-y))
+
+$(obj)/%.stub.o: OBJCOPYFLAGS := --rename-section .data=.data.efistub
+$(obj)/%.stub.o: $(obj)/%.o FORCE
+ $(call if_changed,objcopy)