efi_loader: Enable RISC-V support

We have almost all pieces needed to support RISC-V UEFI binaries in place already.
The only missing piece are ELF relocations for runtime code and
data.

This patch adds respective support in the linker script and the runtime
relocation code. It also allows users to enable the EFI_LOADER configuration
switch on RISC-V platforms.

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

diff --git a/arch/riscv/cpu/nx25/u-boot.lds b/arch/riscv/cpu/nx25/u-boot.lds
index 86ebc9f..c53829a 100644 (file)
--- a/arch/riscv/cpu/nx25/u-boot.lds
+++ b/arch/riscv/cpu/nx25/u-boot.lds
@@ -39,6 +39,22 @@ SECTIONS
 
     . = ALIGN(4);
 
+       .efi_runtime : {
+                __efi_runtime_start = .;
+               *(efi_runtime_text)
+               *(efi_runtime_data)
+                __efi_runtime_stop = .;
+       }
+
+       .efi_runtime_rel : {
+                __efi_runtime_rel_start = .;
+               *(.relaefi_runtime_text)
+               *(.relaefi_runtime_data)
+                __efi_runtime_rel_stop = .;
+       }
+
+    . = ALIGN(4);
+
     /DISCARD/ : { *(.rela.plt*) }
     .rela.dyn : {
         __rel_dyn_start = .;

diff --git a/cmd/Kconfig b/cmd/Kconfig
index d532c9f..1a1ca60 100644 (file)
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -228,7 +228,7 @@ config CMD_BOOTEFI
 
 config CMD_BOOTEFI_HELLO_COMPILE
        bool "Compile a standard EFI hello world binary for testing"
-       depends on CMD_BOOTEFI && (ARM || X86)
+       depends on CMD_BOOTEFI && (ARM || X86 || RISCV)
        default y
        help
          This compiles a standard EFI hello world application with U-Boot so

diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index d38780b..2909e76 100644 (file)
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -1,6 +1,6 @@
 config EFI_LOADER
        bool "Support running EFI Applications in U-Boot"
-       depends on (ARM || X86) && OF_LIBFDT
+       depends on (ARM || X86 || RISCV) && OF_LIBFDT
        # We do not support bootefi booting ARMv7 in non-secure mode
        depends on !ARMV7_NONSEC
        # We need EFI_STUB_64BIT to be set on x86_64 with EFI_STUB

diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
index 042f9ae..241090f 100644 (file)
--- a/lib/efi_loader/efi_runtime.c
+++ b/lib/efi_loader/efi_runtime.c
@@ -40,6 +40,25 @@ static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void);
 #include <asm/elf.h>
 #define R_RELATIVE     R_386_RELATIVE
 #define R_MASK         0xffULL
+#elif defined(CONFIG_RISCV)
+#include <elf.h>
+#define R_RELATIVE     R_RISCV_RELATIVE
+#define R_MASK         0xffULL
+#define IS_RELA                1
+
+struct dyn_sym {
+       ulong foo1;
+       ulong addr;
+       u32 foo2;
+       u32 foo3;
+};
+#ifdef CONFIG_CPU_RISCV_32
+#define R_ABSOLUTE     R_RISCV_32
+#define SYM_INDEX      8
+#else
+#define R_ABSOLUTE     R_RISCV_64
+#define SYM_INDEX      32
+#endif
 #else
 #error Need to add relocation awareness
 #endif
@@ -246,15 +265,27 @@ void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
 
                p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
 
-               if ((rel->info & R_MASK) != R_RELATIVE) {
-                       continue;
-               }
+               debug("%s: rel->info=%#lx *p=%#lx rel->offset=%p\n", __func__, rel->info, *p, rel->offset);
 
+               switch (rel->info & R_MASK) {
+               case R_RELATIVE:
 #ifdef IS_RELA
                newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
 #else
                newaddr = *p - lastoff + offset;
 #endif
+                       break;
+#ifdef R_ABSOLUTE
+               case R_ABSOLUTE: {
+                       ulong symidx = rel->info >> SYM_INDEX;
+                       extern struct dyn_sym __dyn_sym_start[];
+                       newaddr = __dyn_sym_start[symidx].addr + offset;
+                       break;
+               }
+#endif
+               default:
+                       continue;
+               }
 
                /* Check if the relocation is inside bounds */
                if (map && ((newaddr < map->virtual_start) ||