[PATCH v3 4/4] sf: Provide a command to access memory-mapped SPI
Simon Glass
sjg at chromium.org
Sun Aug 1 23:12:45 CEST 2021
Add a new 'sf mmap' function to show the address of a SPI offset, if the
hardware supports it. This is useful on x86 systems.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
Changes in v3:
- Add configuration and return value also
arch/Kconfig | 2 ++
cmd/Kconfig | 8 ++++++
cmd/sf.c | 35 +++++++++++++++++++++++++++
doc/usage/sf.rst | 63 ++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 108 insertions(+)
diff --git a/arch/Kconfig b/arch/Kconfig
index b6f9e177b64..0c718535279 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -136,6 +136,7 @@ config SANDBOX
imply CMD_LZMADEC
imply CMD_SATA
imply CMD_SF
+ imply CMD_SF_MMAP
imply CMD_SF_TEST
imply CRC32_VERIFY
imply FAT_WRITE
@@ -201,6 +202,7 @@ config X86
imply CMD_IRQ
imply CMD_PCI
imply CMD_SF
+ imply CMD_SF_MMAP
imply CMD_SF_TEST
imply CMD_ZBOOT
imply DM_ETH
diff --git a/cmd/Kconfig b/cmd/Kconfig
index ffef3cc76ca..e96b6e798bb 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1273,6 +1273,14 @@ config CMD_SF
help
SPI Flash support
+config CMD_SF_MMAP
+ bool "sf mmap - Access memory-mapped SPI flash"
+ depends on CMD_SF
+ help
+ On some systems part of the SPI flash is mapped into mmemory. This
+ command provides a way to map a SPI-flash offset to a memory address,
+ so that the contents can be browsed using 'md', for example.
+
config CMD_SF_TEST
bool "sf test - Allow testing of SPI flash"
depends on CMD_SF
diff --git a/cmd/sf.c b/cmd/sf.c
index d4f5ecee38c..28b480acc58 100644
--- a/cmd/sf.c
+++ b/cmd/sf.c
@@ -384,6 +384,36 @@ static int do_spi_protect(int argc, char *const argv[])
return ret == 0 ? 0 : 1;
}
+static int do_spi_flash_mmap(int argc, char *const argv[])
+{
+ loff_t offset, len, maxsize;
+ uint map_offset, map_size;
+ ulong map_base;
+ int dev = 0;
+ int ret;
+
+ if (argc < 2)
+ return CMD_RET_USAGE;
+
+ ret = mtd_arg_off_size(argc - 1, &argv[1], &dev, &offset, &len,
+ &maxsize, MTD_DEV_TYPE_NOR, flash->size);
+ if (ret)
+ return ret;
+
+ ret = dm_spi_get_mmap(flash->dev, &map_base, &map_size, &map_offset);
+ if (ret) {
+ printf("Mapping not available (err=%d)\n", ret);
+ return CMD_RET_FAILURE;
+ }
+ if (offset < 0 || offset + len > map_size) {
+ printf("Offset out of range (map size %x)\n", map_size);
+ return CMD_RET_FAILURE;
+ }
+ printf("%lx\n", map_base + (ulong)offset);
+
+ return 0;
+}
+
enum {
STAGE_ERASE,
STAGE_CHECK,
@@ -580,6 +610,8 @@ static int do_spi_flash(struct cmd_tbl *cmdtp, int flag, int argc,
ret = do_spi_flash_erase(argc, argv);
else if (strcmp(cmd, "protect") == 0)
ret = do_spi_protect(argc, argv);
+ else if (IS_ENABLED(CONFIG_CMD_SF_MMAP) && !strcmp(cmd, "mmap"))
+ ret = do_spi_flash_mmap(argc, argv);
else if (IS_ENABLED(CONFIG_CMD_SF_TEST) && !strcmp(cmd, "test"))
ret = do_spi_flash_test(argc, argv);
else
@@ -611,6 +643,9 @@ static const char long_help[] =
" or to start of mtd `partition'\n"
"sf protect lock/unlock sector len - protect/unprotect 'len' bytes starting\n"
" at address 'sector'"
+#ifdef CONFIG_CMD_SF_MMAP
+ "\nsf mmap offset len - get memory address of SPI-flash offset\n"
+#endif
#ifdef CONFIG_CMD_SF_TEST
"\nsf test offset len - run a very basic destructive test"
#endif
diff --git a/doc/usage/sf.rst b/doc/usage/sf.rst
index 6ace1b428d9..b89c0fd5b01 100644
--- a/doc/usage/sf.rst
+++ b/doc/usage/sf.rst
@@ -14,6 +14,7 @@ Synopis
sf erase <offset>|<partition> <len>
sf update <addr> <offset>|<partition> <len>
sf protect lock|unlock <sector> <len>
+ sf mmap <offset>|<partition> <len>
sf test <offset>|<partition> <len>
Description
@@ -143,6 +144,16 @@ lock|unlock
Number of bytes to lock/unlock
+Memory-mapped flash
+-------------------
+
+On some systems part of the SPI flash is mapped into mmemory. With *sf mmap*
+you can map a SPI-flash offset to a memory address, so that the contents can be
+browsed using 'md', for example.
+
+The command will fail if this is not supported by the hardware or driver.
+
+
Test
~~~~
@@ -236,6 +247,58 @@ This second example is running on coral, an x86 Chromebook::
2 write: 227 ticks, 2255 KiB/s 18.040 Mbps
3 read: 189 ticks, 2708 KiB/s 21.664 Mbps
+ # On coral, SPI flash offset 0 corresponds to address ff081000 in memory
+ => sf mmap 0 1000
+ device 0 offset 0x0, size 0x1000
+ ff081000
+
+ # See below for how this address was obtained
+ => sf mmap e80000 11e18
+ device 0 offset 0xe80000, size 0x11e18
+ fff01000
+ => md fff01000
+ fff01000: b2e8e089 89000030 30b4e8c4 c0310000 ....0......0..1.
+ fff01010: 002c95e8 2ce8e800 feeb0000 dfe8c489 ..,....,........
+ fff01020: f400002c 83f4fdeb d4e80cec 3100001e ,..............1
+ fff01030: 0cc483c0 f883c3c3 8b0b770a df408504 .........w.... at .
+ fff01040: c085fef1 c8b80575 c3fef1e5 53565755 ....u.......UWVS
+ fff01050: 89c38951 2404c7c5 80000002 8924048b Q......$......$.
+ fff01060: 89a20fdf 89fb89de 75890045 084d8904 ........E..u..M.
+ fff01070: ff0c5589 c5832404 243c8110 80000005 .U...$....<$....
+ fff01080: 43c6da75 3b800030 43037520 d889f8eb u..C0..; u.C....
+ fff01090: 5f5e5b5a 80e6c35d 535657c3 e7e8c689 Z[^_]....WVS....
+ fff010a0: 89000069 00a164c3 8b000000 408b4c56 i....d......VL.@
+ fff010b0: 0cec837c ddb9ff6a e8fef1e5 00004e01 |...j........N..
+ fff010c0: a1640389 00000000 1c80b60f 66000001 ..d............f
+ fff010d0: b80c4389 00000001 a20fdf89 fb89de89 .C..............
+ fff010e0: 89104389 c4831453 5bc03110 56c35f5e .C..S....1.[^_.V
+ fff010f0: 14ec8353 ce89d389 0000a164 b60f0000 S.......d.......
+
+
+The offset e80000 was obtained using the following binman command, to find the
+location of U-Boot SPL::
+
+ $ binman ls -i /tmp/b/chromebook_coral/u-boot.rom
+ Name Image-pos Size Entry-type Offset Uncomp-size
+ ------------------------------------------------------------------------------------------------------
+ main-section 0 1000000 section 0
+ spl e80000 11e18 u-boot-spl ffe80000
+ u-boot d00000 9106e u-boot ffd00000
+ ...
+
.. _SPI documentation:
https://en.wikipedia.org/wiki/Serial_Peripheral_Interface
+
+
+Configuration
+-------------
+
+The *sf* command is only available if `CONFIG_CMD_SF=y`. Note that it depends on
+`CONFIG_DM_SPI_FLASH`.
+
+Return value
+------------
+
+The return value $? is set to 0 (true) if the command succeded and to 1 (false)
+otherwise.
--
2.32.0.554.ge1b32706d8-goog
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