diff mbox series

[v7,08/11] RISC-V: Add auxiliary files

Message ID 20190212163218.63130-1-agraf@suse.de
State Accepted
Commit 861212333e09a455dd3b7eaab71f1eefb676b39e
Headers show
Series None | expand

Commit Message

Alexander Graf Feb. 12, 2019, 4:32 p.m. UTC
To support a new architecture we need to provide a few helper functions
for memory, cache, timer, etc support.

This patch adds the remainders of those. Some bits are still disabled,
as I couldn't guarantee that we're always running on models / in modes
where the respective hardware is available.

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


---

v2 -> v3:

  - Fix riscv32 target

v3 -> v4:

  - Change copyright from 2013 to 2018
  - Fix coding style
  - Resurrect time reading code
  - Add fence.i for icache flush

v4 -> v5:

  - Mark grub_arch_sync_dma_caches args as unused
  - Whitespace fix

v6 -> v7:

  - Fix cast on riscv32
---
 grub-core/kern/riscv/cache.c       | 63 +++++++++++++++++++++++++++++++
 grub-core/kern/riscv/cache_flush.S | 44 ++++++++++++++++++++++
 grub-core/kern/riscv/efi/init.c    | 76 ++++++++++++++++++++++++++++++++++++++
 include/grub/riscv32/efi/memory.h  |  6 +++
 include/grub/riscv32/time.h        | 28 ++++++++++++++
 include/grub/riscv32/types.h       | 34 +++++++++++++++++
 include/grub/riscv64/efi/memory.h  |  6 +++
 include/grub/riscv64/time.h        | 28 ++++++++++++++
 include/grub/riscv64/types.h       | 34 +++++++++++++++++
 9 files changed, 319 insertions(+)
 create mode 100644 grub-core/kern/riscv/cache.c
 create mode 100644 grub-core/kern/riscv/cache_flush.S
 create mode 100644 grub-core/kern/riscv/efi/init.c
 create mode 100644 include/grub/riscv32/efi/memory.h
 create mode 100644 include/grub/riscv32/time.h
 create mode 100644 include/grub/riscv32/types.h
 create mode 100644 include/grub/riscv64/efi/memory.h
 create mode 100644 include/grub/riscv64/time.h
 create mode 100644 include/grub/riscv64/types.h

-- 
2.12.3


_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel

Comments

Alistair Francis Feb. 13, 2019, 12:48 a.m. UTC | #1
On Tue, 2019-02-12 at 17:32 +0100, Alexander Graf wrote:
> To support a new architecture we need to provide a few helper

> functions

> for memory, cache, timer, etc support.

> 

> This patch adds the remainders of those. Some bits are still

> disabled,

> as I couldn't guarantee that we're always running on models / in

> modes

> where the respective hardware is available.

> 

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


Reviewed-by: Alistair Francis <alistair.francis@wdc.com>


Alistair

> 

> ---

> 

> v2 -> v3:

> 

>   - Fix riscv32 target

> 

> v3 -> v4:

> 

>   - Change copyright from 2013 to 2018

>   - Fix coding style

>   - Resurrect time reading code

>   - Add fence.i for icache flush

> 

> v4 -> v5:

> 

>   - Mark grub_arch_sync_dma_caches args as unused

>   - Whitespace fix

> 

> v6 -> v7:

> 

>   - Fix cast on riscv32

> ---

>  grub-core/kern/riscv/cache.c       | 63

> +++++++++++++++++++++++++++++++

>  grub-core/kern/riscv/cache_flush.S | 44 ++++++++++++++++++++++

>  grub-core/kern/riscv/efi/init.c    | 76

> ++++++++++++++++++++++++++++++++++++++

>  include/grub/riscv32/efi/memory.h  |  6 +++

>  include/grub/riscv32/time.h        | 28 ++++++++++++++

>  include/grub/riscv32/types.h       | 34 +++++++++++++++++

>  include/grub/riscv64/efi/memory.h  |  6 +++

>  include/grub/riscv64/time.h        | 28 ++++++++++++++

>  include/grub/riscv64/types.h       | 34 +++++++++++++++++

>  9 files changed, 319 insertions(+)

>  create mode 100644 grub-core/kern/riscv/cache.c

>  create mode 100644 grub-core/kern/riscv/cache_flush.S

>  create mode 100644 grub-core/kern/riscv/efi/init.c

>  create mode 100644 include/grub/riscv32/efi/memory.h

>  create mode 100644 include/grub/riscv32/time.h

>  create mode 100644 include/grub/riscv32/types.h

>  create mode 100644 include/grub/riscv64/efi/memory.h

>  create mode 100644 include/grub/riscv64/time.h

>  create mode 100644 include/grub/riscv64/types.h

> 

> diff --git a/grub-core/kern/riscv/cache.c b/grub-

> core/kern/riscv/cache.c

> new file mode 100644

> index 000000000..47777a033

> --- /dev/null

> +++ b/grub-core/kern/riscv/cache.c

> @@ -0,0 +1,63 @@

> +/*

> + *  GRUB  --  GRand Unified Bootloader

> + *  Copyright (C) 2018  Free Software Foundation, Inc.

> + *

> + *  GRUB is free software: you can redistribute it and/or modify

> + *  it under the terms of the GNU General Public License as

> published by

> + *  the Free Software Foundation, either version 3 of the License,

> or

> + *  (at your option) any later version.

> + *

> + *  GRUB is distributed in the hope that it will be useful,

> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of

> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

> + *  GNU General Public License for more details.

> + *

> + *  You should have received a copy of the GNU General Public

> License

> + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>;.

> + */

> +

> +#include <grub/cache.h>

> +#include <grub/misc.h>

> +

> +static grub_int64_t dlinesz;

> +static grub_int64_t ilinesz;

> +

> +/* Prototypes for asm functions. */

> +void grub_arch_clean_dcache_range (grub_addr_t beg, grub_addr_t end,

> +				   grub_size_t line_size);

> +void grub_arch_invalidate_icache_range (grub_addr_t beg, grub_addr_t

> end,

> +					grub_size_t line_size);

> +

> +static void

> +probe_caches (void)

> +{

> +  /* TODO */

> +  dlinesz = 32;

> +  ilinesz = 32;

> +}

> +

> +void

> +grub_arch_sync_caches (void *address, grub_size_t len)

> +{

> +  grub_size_t start, end, max_align;

> +

> +  if (dlinesz == 0)

> +    probe_caches();

> +  if (dlinesz == 0)

> +    grub_fatal ("Unknown cache line size!");

> +

> +  max_align = dlinesz > ilinesz ? dlinesz : ilinesz;

> +

> +  start = ALIGN_DOWN ((grub_size_t) address, max_align);

> +  end = ALIGN_UP ((grub_size_t) address + len, max_align);

> +

> +  grub_arch_clean_dcache_range (start, end, dlinesz);

> +  grub_arch_invalidate_icache_range (start, end, ilinesz);

> +}

> +

> +void

> +grub_arch_sync_dma_caches (volatile void *address

> __attribute__((unused)),

> +			   grub_size_t len __attribute__((unused)))

> +{

> +  /* DMA incoherent devices not supported yet */

> +}

> diff --git a/grub-core/kern/riscv/cache_flush.S b/grub-

> core/kern/riscv/cache_flush.S

> new file mode 100644

> index 000000000..41de6e411

> --- /dev/null

> +++ b/grub-core/kern/riscv/cache_flush.S

> @@ -0,0 +1,44 @@

> +/*

> + *  GRUB  --  GRand Unified Bootloader

> + *  Copyright (C) 2018  Free Software Foundation, Inc.

> + *

> + *  GRUB is free software: you can redistribute it and/or modify

> + *  it under the terms of the GNU General Public License as

> published by

> + *  the Free Software Foundation, either version 3 of the License,

> or

> + *  (at your option) any later version.

> + *

> + *  GRUB is distributed in the hope that it will be useful,

> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of

> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

> + *  GNU General Public License for more details.

> + *

> + *  You should have received a copy of the GNU General Public

> License

> + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>;.

> + */

> +

> +#include <grub/symbol.h>

> +

> +	.file	"cache_flush.S"

> +	.text

> +

> +/*

> + * Simple cache maintenance functions

> + */

> +

> +/*

> + * a0 - *beg (inclusive)

> + * a1 - *end (exclusive)

> + * a2 - line size

> +*/

> +FUNCTION(grub_arch_clean_dcache_range)

> +	/* TODO */

> +	ret

> +

> +/*

> + * a0 - *beg (inclusive)

> + * a1 - *end (exclusive)

> + * a2 - line size

> + */

> +FUNCTION(grub_arch_invalidate_icache_range)

> +	fence.i

> +	ret

> diff --git a/grub-core/kern/riscv/efi/init.c b/grub-

> core/kern/riscv/efi/init.c

> new file mode 100644

> index 000000000..7eb1969d0

> --- /dev/null

> +++ b/grub-core/kern/riscv/efi/init.c

> @@ -0,0 +1,76 @@

> +/* init.c - initialize a riscv-based EFI system */

> +/*

> + *  GRUB  --  GRand Unified Bootloader

> + *  Copyright (C) 2018 Free Software Foundation, Inc.

> + *

> + *  GRUB is free software: you can redistribute it and/or modify

> + *  it under the terms of the GNU General Public License as

> published by

> + *  the Free Software Foundation, either version 3 of the License,

> or

> + *  (at your option) any later version.

> + *

> + *  GRUB is distributed in the hope that it will be useful,

> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of

> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

> + *  GNU General Public License for more details.

> + *

> + *  You should have received a copy of the GNU General Public

> License

> + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>;.

> + */

> +

> +#include <grub/env.h>

> +#include <grub/kernel.h>

> +#include <grub/misc.h>

> +#include <grub/mm.h>

> +#include <grub/time.h>

> +#include <grub/efi/efi.h>

> +#include <grub/loader.h>

> +

> +static grub_uint64_t timer_frequency_in_khz;

> +

> +static grub_uint64_t

> +grub_efi_get_time_ms (void)

> +{

> +  grub_uint64_t tmr;

> +

> +#if __riscv_xlen == 64

> +  asm volatile ("rdcycle %0" : "=r" (tmr));

> +#else

> +  grub_uint32_t lo, hi, tmp;

> +  asm volatile (

> +    "1:\n"

> +    "rdcycleh %0\n"

> +    "rdcycle %1\n"

> +    "rdcycleh %2\n"

> +    "bne %0, %2, 1b"

> +    : "=&r" (hi), "=&r" (lo), "=&r" (tmp));

> +  tmr = ((grub_uint64_t)hi << 32) | lo;

> +#endif

> +

> +  return tmr / timer_frequency_in_khz;

> +}

> +

> +void

> +grub_machine_init (void)

> +{

> +  grub_uint64_t time_before, time_after;

> +

> +  grub_efi_init ();

> +

> +  /* Calculate timer frequency */

> +  timer_frequency_in_khz = 1;

> +  time_before = grub_efi_get_time_ms();

> +  grub_efi_stall(1000);

> +  time_after = grub_efi_get_time_ms();

> +  timer_frequency_in_khz = time_after - time_before;

> +

> +  grub_install_get_time_ms (grub_efi_get_time_ms);

> +}

> +

> +void

> +grub_machine_fini (int flags)

> +{

> +  if (!(flags & GRUB_LOADER_FLAG_NORETURN))

> +    return;

> +

> +  grub_efi_fini ();

> +}

> diff --git a/include/grub/riscv32/efi/memory.h

> b/include/grub/riscv32/efi/memory.h

> new file mode 100644

> index 000000000..e61c474ff

> --- /dev/null

> +++ b/include/grub/riscv32/efi/memory.h

> @@ -0,0 +1,6 @@

> +#ifndef GRUB_MEMORY_CPU_HEADER

> +#include <grub/efi/memory.h>

> +

> +#define GRUB_EFI_MAX_USABLE_ADDRESS 0xffffffffUL

> +

> +#endif /* ! GRUB_MEMORY_CPU_HEADER */

> diff --git a/include/grub/riscv32/time.h

> b/include/grub/riscv32/time.h

> new file mode 100644

> index 000000000..20abd648b

> --- /dev/null

> +++ b/include/grub/riscv32/time.h

> @@ -0,0 +1,28 @@

> +/*

> + *  GRUB  --  GRand Unified Bootloader

> + *  Copyright (C) 2018  Free Software Foundation, Inc.

> + *

> + *  GRUB is free software: you can redistribute it and/or modify

> + *  it under the terms of the GNU General Public License as

> published by

> + *  the Free Software Foundation, either version 3 of the License,

> or

> + *  (at your option) any later version.

> + *

> + *  GRUB is distributed in the hope that it will be useful,

> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of

> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

> + *  GNU General Public License for more details.

> + *

> + *  You should have received a copy of the GNU General Public

> License

> + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>;.

> + */

> +

> +#ifndef KERNEL_CPU_TIME_HEADER

> +#define KERNEL_CPU_TIME_HEADER	1

> +

> +static __inline void

> +grub_cpu_idle (void)

> +{

> +  /* TODO */

> +}

> +

> +#endif /* ! KERNEL_CPU_TIME_HEADER */

> diff --git a/include/grub/riscv32/types.h

> b/include/grub/riscv32/types.h

> new file mode 100644

> index 000000000..fac57a752

> --- /dev/null

> +++ b/include/grub/riscv32/types.h

> @@ -0,0 +1,34 @@

> +/*

> + *  GRUB  --  GRand Unified Bootloader

> + *  Copyright (C) 2018  Free Software Foundation, Inc.

> + *

> + *  GRUB is free software: you can redistribute it and/or modify

> + *  it under the terms of the GNU General Public License as

> published by

> + *  the Free Software Foundation, either version 3 of the License,

> or

> + *  (at your option) any later version.

> + *

> + *  GRUB is distributed in the hope that it will be useful,

> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of

> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

> + *  GNU General Public License for more details.

> + *

> + *  You should have received a copy of the GNU General Public

> License

> + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>;.

> + */

> +

> +#ifndef GRUB_TYPES_CPU_HEADER

> +#define GRUB_TYPES_CPU_HEADER	1

> +

> +/* The size of void *.  */

> +#define GRUB_TARGET_SIZEOF_VOID_P	4

> +

> +/* The size of long.  */

> +#define GRUB_TARGET_SIZEOF_LONG		4

> +

> +/* currently only support little-endian.  */

> +#undef GRUB_TARGET_WORDS_BIGENDIAN

> +

> +/* Unaligned accesses can be very slow, so avoid them */

> +#undef GRUB_HAVE_UNALIGNED_ACCESS

> +

> +#endif /* ! GRUB_TYPES_CPU_HEADER */

> diff --git a/include/grub/riscv64/efi/memory.h

> b/include/grub/riscv64/efi/memory.h

> new file mode 100644

> index 000000000..c6cb32417

> --- /dev/null

> +++ b/include/grub/riscv64/efi/memory.h

> @@ -0,0 +1,6 @@

> +#ifndef GRUB_MEMORY_CPU_HEADER

> +#include <grub/efi/memory.h>

> +

> +#define GRUB_EFI_MAX_USABLE_ADDRESS 0xffffffffffffULL

> +

> +#endif /* ! GRUB_MEMORY_CPU_HEADER */

> diff --git a/include/grub/riscv64/time.h

> b/include/grub/riscv64/time.h

> new file mode 100644

> index 000000000..20abd648b

> --- /dev/null

> +++ b/include/grub/riscv64/time.h

> @@ -0,0 +1,28 @@

> +/*

> + *  GRUB  --  GRand Unified Bootloader

> + *  Copyright (C) 2018  Free Software Foundation, Inc.

> + *

> + *  GRUB is free software: you can redistribute it and/or modify

> + *  it under the terms of the GNU General Public License as

> published by

> + *  the Free Software Foundation, either version 3 of the License,

> or

> + *  (at your option) any later version.

> + *

> + *  GRUB is distributed in the hope that it will be useful,

> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of

> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

> + *  GNU General Public License for more details.

> + *

> + *  You should have received a copy of the GNU General Public

> License

> + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>;.

> + */

> +

> +#ifndef KERNEL_CPU_TIME_HEADER

> +#define KERNEL_CPU_TIME_HEADER	1

> +

> +static __inline void

> +grub_cpu_idle (void)

> +{

> +  /* TODO */

> +}

> +

> +#endif /* ! KERNEL_CPU_TIME_HEADER */

> diff --git a/include/grub/riscv64/types.h

> b/include/grub/riscv64/types.h

> new file mode 100644

> index 000000000..c6bcad470

> --- /dev/null

> +++ b/include/grub/riscv64/types.h

> @@ -0,0 +1,34 @@

> +/*

> + *  GRUB  --  GRand Unified Bootloader

> + *  Copyright (C) 2018  Free Software Foundation, Inc.

> + *

> + *  GRUB is free software: you can redistribute it and/or modify

> + *  it under the terms of the GNU General Public License as

> published by

> + *  the Free Software Foundation, either version 3 of the License,

> or

> + *  (at your option) any later version.

> + *

> + *  GRUB is distributed in the hope that it will be useful,

> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of

> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

> + *  GNU General Public License for more details.

> + *

> + *  You should have received a copy of the GNU General Public

> License

> + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>;.

> + */

> +

> +#ifndef GRUB_TYPES_CPU_HEADER

> +#define GRUB_TYPES_CPU_HEADER	1

> +

> +/* The size of void *.  */

> +#define GRUB_TARGET_SIZEOF_VOID_P	8

> +

> +/* The size of long.  */

> +#define GRUB_TARGET_SIZEOF_LONG		8

> +

> +/* currently only support little-endian.  */

> +#undef GRUB_TARGET_WORDS_BIGENDIAN

> +

> +/* Unaligned accesses can be very slow, so avoid them */

> +#undef GRUB_HAVE_UNALIGNED_ACCESS

> +

> +#endif /* ! GRUB_TYPES_CPU_HEADER */

_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel
Daniel Kiper Feb. 18, 2019, 7:44 p.m. UTC | #2
On Wed, Feb 13, 2019 at 12:48:44AM +0000, Alistair Francis wrote:
> On Tue, 2019-02-12 at 17:32 +0100, Alexander Graf wrote:

> > To support a new architecture we need to provide a few helper

> > functions

> > for memory, cache, timer, etc support.

> >

> > This patch adds the remainders of those. Some bits are still

> > disabled,

> > as I couldn't guarantee that we're always running on models / in

> > modes

> > where the respective hardware is available.

> >

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

>

> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>


Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>


Daniel

_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel
diff mbox series

Patch

diff --git a/grub-core/kern/riscv/cache.c b/grub-core/kern/riscv/cache.c
new file mode 100644
index 000000000..47777a033
--- /dev/null
+++ b/grub-core/kern/riscv/cache.c
@@ -0,0 +1,63 @@ 
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2018  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/cache.h>
+#include <grub/misc.h>
+
+static grub_int64_t dlinesz;
+static grub_int64_t ilinesz;
+
+/* Prototypes for asm functions. */
+void grub_arch_clean_dcache_range (grub_addr_t beg, grub_addr_t end,
+				   grub_size_t line_size);
+void grub_arch_invalidate_icache_range (grub_addr_t beg, grub_addr_t end,
+					grub_size_t line_size);
+
+static void
+probe_caches (void)
+{
+  /* TODO */
+  dlinesz = 32;
+  ilinesz = 32;
+}
+
+void
+grub_arch_sync_caches (void *address, grub_size_t len)
+{
+  grub_size_t start, end, max_align;
+
+  if (dlinesz == 0)
+    probe_caches();
+  if (dlinesz == 0)
+    grub_fatal ("Unknown cache line size!");
+
+  max_align = dlinesz > ilinesz ? dlinesz : ilinesz;
+
+  start = ALIGN_DOWN ((grub_size_t) address, max_align);
+  end = ALIGN_UP ((grub_size_t) address + len, max_align);
+
+  grub_arch_clean_dcache_range (start, end, dlinesz);
+  grub_arch_invalidate_icache_range (start, end, ilinesz);
+}
+
+void
+grub_arch_sync_dma_caches (volatile void *address __attribute__((unused)),
+			   grub_size_t len __attribute__((unused)))
+{
+  /* DMA incoherent devices not supported yet */
+}
diff --git a/grub-core/kern/riscv/cache_flush.S b/grub-core/kern/riscv/cache_flush.S
new file mode 100644
index 000000000..41de6e411
--- /dev/null
+++ b/grub-core/kern/riscv/cache_flush.S
@@ -0,0 +1,44 @@ 
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2018  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/symbol.h>
+
+	.file	"cache_flush.S"
+	.text
+
+/*
+ * Simple cache maintenance functions
+ */
+
+/*
+ * a0 - *beg (inclusive)
+ * a1 - *end (exclusive)
+ * a2 - line size
+*/
+FUNCTION(grub_arch_clean_dcache_range)
+	/* TODO */
+	ret
+
+/*
+ * a0 - *beg (inclusive)
+ * a1 - *end (exclusive)
+ * a2 - line size
+ */
+FUNCTION(grub_arch_invalidate_icache_range)
+	fence.i
+	ret
diff --git a/grub-core/kern/riscv/efi/init.c b/grub-core/kern/riscv/efi/init.c
new file mode 100644
index 000000000..7eb1969d0
--- /dev/null
+++ b/grub-core/kern/riscv/efi/init.c
@@ -0,0 +1,76 @@ 
+/* init.c - initialize a riscv-based EFI system */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2018 Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/env.h>
+#include <grub/kernel.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+#include <grub/time.h>
+#include <grub/efi/efi.h>
+#include <grub/loader.h>
+
+static grub_uint64_t timer_frequency_in_khz;
+
+static grub_uint64_t
+grub_efi_get_time_ms (void)
+{
+  grub_uint64_t tmr;
+
+#if __riscv_xlen == 64
+  asm volatile ("rdcycle %0" : "=r" (tmr));
+#else
+  grub_uint32_t lo, hi, tmp;
+  asm volatile (
+    "1:\n"
+    "rdcycleh %0\n"
+    "rdcycle %1\n"
+    "rdcycleh %2\n"
+    "bne %0, %2, 1b"
+    : "=&r" (hi), "=&r" (lo), "=&r" (tmp));
+  tmr = ((grub_uint64_t)hi << 32) | lo;
+#endif
+
+  return tmr / timer_frequency_in_khz;
+}
+
+void
+grub_machine_init (void)
+{
+  grub_uint64_t time_before, time_after;
+
+  grub_efi_init ();
+
+  /* Calculate timer frequency */
+  timer_frequency_in_khz = 1;
+  time_before = grub_efi_get_time_ms();
+  grub_efi_stall(1000);
+  time_after = grub_efi_get_time_ms();
+  timer_frequency_in_khz = time_after - time_before;
+
+  grub_install_get_time_ms (grub_efi_get_time_ms);
+}
+
+void
+grub_machine_fini (int flags)
+{
+  if (!(flags & GRUB_LOADER_FLAG_NORETURN))
+    return;
+
+  grub_efi_fini ();
+}
diff --git a/include/grub/riscv32/efi/memory.h b/include/grub/riscv32/efi/memory.h
new file mode 100644
index 000000000..e61c474ff
--- /dev/null
+++ b/include/grub/riscv32/efi/memory.h
@@ -0,0 +1,6 @@ 
+#ifndef GRUB_MEMORY_CPU_HEADER
+#include <grub/efi/memory.h>
+
+#define GRUB_EFI_MAX_USABLE_ADDRESS 0xffffffffUL
+
+#endif /* ! GRUB_MEMORY_CPU_HEADER */
diff --git a/include/grub/riscv32/time.h b/include/grub/riscv32/time.h
new file mode 100644
index 000000000..20abd648b
--- /dev/null
+++ b/include/grub/riscv32/time.h
@@ -0,0 +1,28 @@ 
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2018  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef KERNEL_CPU_TIME_HEADER
+#define KERNEL_CPU_TIME_HEADER	1
+
+static __inline void
+grub_cpu_idle (void)
+{
+  /* TODO */
+}
+
+#endif /* ! KERNEL_CPU_TIME_HEADER */
diff --git a/include/grub/riscv32/types.h b/include/grub/riscv32/types.h
new file mode 100644
index 000000000..fac57a752
--- /dev/null
+++ b/include/grub/riscv32/types.h
@@ -0,0 +1,34 @@ 
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2018  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GRUB_TYPES_CPU_HEADER
+#define GRUB_TYPES_CPU_HEADER	1
+
+/* The size of void *.  */
+#define GRUB_TARGET_SIZEOF_VOID_P	4
+
+/* The size of long.  */
+#define GRUB_TARGET_SIZEOF_LONG		4
+
+/* currently only support little-endian.  */
+#undef GRUB_TARGET_WORDS_BIGENDIAN
+
+/* Unaligned accesses can be very slow, so avoid them */
+#undef GRUB_HAVE_UNALIGNED_ACCESS
+
+#endif /* ! GRUB_TYPES_CPU_HEADER */
diff --git a/include/grub/riscv64/efi/memory.h b/include/grub/riscv64/efi/memory.h
new file mode 100644
index 000000000..c6cb32417
--- /dev/null
+++ b/include/grub/riscv64/efi/memory.h
@@ -0,0 +1,6 @@ 
+#ifndef GRUB_MEMORY_CPU_HEADER
+#include <grub/efi/memory.h>
+
+#define GRUB_EFI_MAX_USABLE_ADDRESS 0xffffffffffffULL
+
+#endif /* ! GRUB_MEMORY_CPU_HEADER */
diff --git a/include/grub/riscv64/time.h b/include/grub/riscv64/time.h
new file mode 100644
index 000000000..20abd648b
--- /dev/null
+++ b/include/grub/riscv64/time.h
@@ -0,0 +1,28 @@ 
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2018  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef KERNEL_CPU_TIME_HEADER
+#define KERNEL_CPU_TIME_HEADER	1
+
+static __inline void
+grub_cpu_idle (void)
+{
+  /* TODO */
+}
+
+#endif /* ! KERNEL_CPU_TIME_HEADER */
diff --git a/include/grub/riscv64/types.h b/include/grub/riscv64/types.h
new file mode 100644
index 000000000..c6bcad470
--- /dev/null
+++ b/include/grub/riscv64/types.h
@@ -0,0 +1,34 @@ 
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2018  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GRUB_TYPES_CPU_HEADER
+#define GRUB_TYPES_CPU_HEADER	1
+
+/* The size of void *.  */
+#define GRUB_TARGET_SIZEOF_VOID_P	8
+
+/* The size of long.  */
+#define GRUB_TARGET_SIZEOF_LONG		8
+
+/* currently only support little-endian.  */
+#undef GRUB_TARGET_WORDS_BIGENDIAN
+
+/* Unaligned accesses can be very slow, so avoid them */
+#undef GRUB_HAVE_UNALIGNED_ACCESS
+
+#endif /* ! GRUB_TYPES_CPU_HEADER */