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* [PATCH 1/3] ARM: add fncpy.h from linux v4.6
@ 2016-05-20 12:21 Steffen Trumtrar
  2016-05-20 12:21 ` [PATCH 2/3] firmware: socfpga: set APPLYCFG after loading bitstream Steffen Trumtrar
  2016-05-20 12:21 ` [PATCH 3/3] firmware: add support for compressed images Steffen Trumtrar
  0 siblings, 2 replies; 6+ messages in thread
From: Steffen Trumtrar @ 2016-05-20 12:21 UTC (permalink / raw)
  To: barebox; +Cc: Steffen Trumtrar

Description from the linux commit 5756e9dd0de6d5c307773f8f734c0684b3098fdd:

    ARM: 6640/1: Thumb-2: Symbol manipulation macros for function body copying

    In low-level board support code, there is sometimes a need to
    copy a function body to another location at run-time.

    A straightforward call to memcpy doesn't work in Thumb-2,
    because bit 0 of external Thumb function symbols is set to 1,
    indicating that the function is Thumb.  Without corrective
    measures, this will cause an off-by-one copy, and the copy
    may be called using the wrong instruction set.

    This patch adds an fncpy() macro to help with such copies.

    Particular care is needed, because C doesn't guarantee any
    defined behaviour when casting a function pointer to any other
    type.  This has been observed to lead to strange optimisation
    side-effects when doing the arithmetic which is required in
    order to copy/move function bodies correctly in Thumb-2.

    Thanks to Russell King and Nicolas Pitre for their input
    on this patch.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
---
 arch/arm/include/asm/fncpy.h | 82 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 82 insertions(+)
 create mode 100644 arch/arm/include/asm/fncpy.h

diff --git a/arch/arm/include/asm/fncpy.h b/arch/arm/include/asm/fncpy.h
new file mode 100644
index 000000000000..d13876bffa23
--- /dev/null
+++ b/arch/arm/include/asm/fncpy.h
@@ -0,0 +1,82 @@
+/*
+ * arch/arm/include/asm/fncpy.h - helper macros for function body copying
+ *
+ * Copyright (C) 2011 Linaro Limited
+ *
+ * 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.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+/*
+ * These macros are intended for use when there is a need to copy a low-level
+ * function body into special memory.
+ *
+ * For example, when reconfiguring the SDRAM controller, the code doing the
+ * reconfiguration may need to run from SRAM.
+ *
+ * NOTE: that the copied function body must be entirely self-contained and
+ * position-independent in order for this to work properly.
+ *
+ * NOTE: in order for embedded literals and data to get referenced correctly,
+ * the alignment of functions must be preserved when copying.  To ensure this,
+ * the source and destination addresses for fncpy() must be aligned to a
+ * multiple of 8 bytes: you will be get a BUG() if this condition is not met.
+ * You will typically need a ".align 3" directive in the assembler where the
+ * function to be copied is defined, and ensure that your allocator for the
+ * destination buffer returns 8-byte-aligned pointers.
+ *
+ * Typical usage example:
+ *
+ * extern int f(args);
+ * extern uint32_t size_of_f;
+ * int (*copied_f)(args);
+ * void *sram_buffer;
+ *
+ * copied_f = fncpy(sram_buffer, &f, size_of_f);
+ *
+ * ... later, call the function: ...
+ *
+ * copied_f(args);
+ *
+ * The size of the function to be copied can't be determined from C:
+ * this must be determined by other means, such as adding assmbler directives
+ * in the file where f is defined.
+ */
+
+#ifndef __ASM_FNCPY_H
+#define __ASM_FNCPY_H
+
+#include <linux/types.h>
+#include <linux/string.h>
+
+/*
+ * Minimum alignment requirement for the source and destination addresses
+ * for function copying.
+ */
+#define FNCPY_ALIGN 8
+
+#define fncpy(dest_buf, funcp, size) ({					\
+	uintptr_t __funcp_address;					\
+	typeof(funcp) __result;						\
+									\
+	asm("" : "=r" (__funcp_address) : "0" (funcp));			\
+									\
+	memcpy(dest_buf, (void const *)(__funcp_address & ~1), size);	\
+									\
+	asm("" : "=r" (__result)					\
+		: "0" ((uintptr_t)(dest_buf) | (__funcp_address & 1)));	\
+									\
+	__result;							\
+})
+
+#endif /* !__ASM_FNCPY_H */
-- 
2.8.0.rc3


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^ permalink raw reply	[flat|nested] 6+ messages in thread
* [PATCH 0/3] firmware: Add support for compressed images
@ 2021-06-23  4:33 Sascha Hauer
  2021-06-23  4:33 ` [PATCH 3/3] firmware: add " Sascha Hauer
  0 siblings, 1 reply; 6+ messages in thread
From: Sascha Hauer @ 2021-06-23  4:33 UTC (permalink / raw)
  To: Barebox List

Steffen already sent this. This version has some improvements like
better error reporting. Also we uncompress only files we detect as
compressed files, not just everything we do not detect as unknown file.

Sascha Hauer (2):
  filetype: Add function to check if a filetype is a compressed file
  libfile: Add copy_fd()

Steffen Trumtrar (1):
  firmware: add support for compressed images

 common/firmware.c  | 50 ++++++++++++++++++++++++++++++++++++++++++----
 include/filetype.h | 14 +++++++++++++
 include/libfile.h  |  1 +
 lib/libfile.c      | 34 +++++++++++++++++++++++++++++++
 4 files changed, 95 insertions(+), 4 deletions(-)

-- 
2.29.2


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^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2021-06-23  4:35 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-05-20 12:21 [PATCH 1/3] ARM: add fncpy.h from linux v4.6 Steffen Trumtrar
2016-05-20 12:21 ` [PATCH 2/3] firmware: socfpga: set APPLYCFG after loading bitstream Steffen Trumtrar
2016-05-20 18:24   ` Trent Piepho
2016-05-20 12:21 ` [PATCH 3/3] firmware: add support for compressed images Steffen Trumtrar
2016-05-20 17:51   ` Trent Piepho
2021-06-23  4:33 [PATCH 0/3] firmware: Add " Sascha Hauer
2021-06-23  4:33 ` [PATCH 3/3] firmware: add " Sascha Hauer

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