[Toybox] [PATCH] Support non memory mapped access
Karthikeyan Ramasubramanian
kramasub at google.com
Wed Oct 23 16:02:42 PDT 2024
Add --no-mmap flag to indicate seek and read/write access. This allows
accessing devices that do not support mapping into memory - eg.
/dev/nvram, /dev/msr0 etc.
Also currently only WIDTH bytes are mapped into memory even when more
data is accessed. Fix this by mapping WIDTH * number of data.
Test: ./post_update.sh && m toybox. Push devmem test into DUT and access
/dev/mem through memory mapped access, /dev/nvram & /dev/msr* through
non memory-mapped access.
---
android/device/generated/flags.h | 8 +++--
android/device/generated/help.h | 2 +-
android/device/generated/newtoys.h | 2 +-
android/linux/generated/flags.h | 8 +++--
android/linux/generated/help.h | 2 +-
android/linux/generated/newtoys.h | 2 +-
android/mac/generated/flags.h | 8 +++--
android/mac/generated/help.h | 2 +-
android/mac/generated/newtoys.h | 2 +-
toys/other/devmem.c | 49 +++++++++++++++++++-----------
10 files changed, 53 insertions(+), 32 deletions(-)
diff --git a/android/device/generated/flags.h b/android/device/generated/flags.h
index 9c056073..aa13b2c6 100644
--- a/android/device/generated/flags.h
+++ b/android/device/generated/flags.h
@@ -641,13 +641,14 @@
#undef FOR_demo_utf8towc
#endif
-// devmem <1(no-sync)f: <1(no-sync)f:
+// devmem <1(no-sync)(no-mmap)f: <1(no-sync)(no-mmap)f:
#undef OPTSTR_devmem
-#define OPTSTR_devmem "<1(no-sync)f:"
+#define OPTSTR_devmem "<1(no-sync)(no-mmap)f:"
#ifdef CLEANUP_devmem
#undef CLEANUP_devmem
#undef FOR_devmem
#undef FLAG_f
+#undef FLAG_no_mmap
#undef FLAG_no_sync
#endif
@@ -4547,7 +4548,8 @@
#define TT this.devmem
#endif
#define FLAG_f (1LL<<0)
-#define FLAG_no_sync (1LL<<1)
+#define FLAG_no_mmap (1LL<<1)
+#define FLAG_no_sync (1LL<<2)
#endif
#ifdef FOR_df
diff --git a/android/device/generated/help.h b/android/device/generated/help.h
index 92dd3687..87f92453 100644
--- a/android/device/generated/help.h
+++ b/android/device/generated/help.h
@@ -330,7 +330,7 @@
#define HELP_dos2unix "usage: dos2unix [FILE...]\n\nConvert newline format from dos \"\\r\\n\" to unix \"\\n\".\nIf no files listed copy from stdin, \"-\" is a synonym for stdin."
-#define HELP_devmem "usage: devmem [-f FILE] ADDR [WIDTH [DATA...]]\n\nRead/write physical addresses. WIDTH is 1, 2, 4, or 8 bytes (default 4).\nPrefix ADDR with 0x for hexadecimal, output is in same base as address.\n\n-f FILE File to operate on (default /dev/mem)\n--no-sync Don't open the file with O_SYNC (for cached access)"
+#define HELP_devmem "usage: devmem [-f FILE] ADDR [WIDTH [DATA...]]\n\nRead/write physical addresses. WIDTH is 1, 2, 4, or 8 bytes (default 4).\nPrefix ADDR with 0x for hexadecimal, output is in same base as address.\n\n-f FILE File to operate on (default /dev/mem)\n--no-sync Don't open the file with O_SYNC (for cached access)\n--no-mmap Don't mmap the file"
#define HELP_count "usage: count [-l]\n\n-l Long output (total bytes, human readable, transfer rate, elapsed time)\n\nCopy stdin to stdout, displaying simple progress indicator to stderr."
diff --git a/android/device/generated/newtoys.h b/android/device/generated/newtoys.h
index c41eb83f..e99f4f1c 100644
--- a/android/device/generated/newtoys.h
+++ b/android/device/generated/newtoys.h
@@ -60,7 +60,7 @@ USE_DEMO_MANY_OPTIONS(NEWTOY(demo_many_options, "ZYXWVUTSRQPONMLKJIHGFEDCBAzyxwv
USE_DEMO_NUMBER(NEWTOY(demo_number, "D#=3<3M#<0hcdbs", TOYFLAG_BIN))
USE_DEMO_SCANKEY(NEWTOY(demo_scankey, 0, TOYFLAG_BIN))
USE_DEMO_UTF8TOWC(NEWTOY(demo_utf8towc, 0, TOYFLAG_USR|TOYFLAG_BIN))
-USE_DEVMEM(NEWTOY(devmem, "<1(no-sync)f:", TOYFLAG_USR|TOYFLAG_SBIN))
+USE_DEVMEM(NEWTOY(devmem, "<1(no-sync)(no-mmap)f:", TOYFLAG_USR|TOYFLAG_SBIN))
USE_DF(NEWTOY(df, "HPkhit*a[-HPh]", TOYFLAG_BIN))
USE_DHCP(NEWTOY(dhcp, "V:H:F:x*r:O*A#<0=20T#<0=3t#<0=3s:p:i:SBRCaovqnbf", TOYFLAG_SBIN|TOYFLAG_ROOTONLY))
USE_DHCP6(NEWTOY(dhcp6, "r:A#<0T#<0t#<0s:p:i:SRvqnbf", TOYFLAG_SBIN|TOYFLAG_ROOTONLY))
diff --git a/android/linux/generated/flags.h b/android/linux/generated/flags.h
index e73e4bf8..27fcd60d 100644
--- a/android/linux/generated/flags.h
+++ b/android/linux/generated/flags.h
@@ -641,13 +641,14 @@
#undef FOR_demo_utf8towc
#endif
-// devmem <1(no-sync)f:
+// devmem <1(no-sync)(no-mmap)f:
#undef OPTSTR_devmem
-#define OPTSTR_devmem "<1(no-sync)f:"
+#define OPTSTR_devmem "<1(no-sync)(no-mmap)f:"
#ifdef CLEANUP_devmem
#undef CLEANUP_devmem
#undef FOR_devmem
#undef FLAG_f
+#undef FLAG_no_mmap
#undef FLAG_no_sync
#endif
@@ -4547,7 +4548,8 @@
#define TT this.devmem
#endif
#define FLAG_f (FORCED_FLAG<<0)
-#define FLAG_no_sync (FORCED_FLAG<<1)
+#define FLAG_no_mmap (FORCED_FLAG<<1)
+#define FLAG_no_sync (FORCED_FLAG<<2)
#endif
#ifdef FOR_df
diff --git a/android/linux/generated/help.h b/android/linux/generated/help.h
index f25a0785..eccc159a 100644
--- a/android/linux/generated/help.h
+++ b/android/linux/generated/help.h
@@ -332,7 +332,7 @@
#define HELP_dos2unix "usage: dos2unix [FILE...]\n\nConvert newline format from dos \"\\r\\n\" to unix \"\\n\".\nIf no files listed copy from stdin, \"-\" is a synonym for stdin."
-#define HELP_devmem "usage: devmem [-f FILE] ADDR [WIDTH [DATA...]]\n\nRead/write physical addresses. WIDTH is 1, 2, 4, or 8 bytes (default 4).\nPrefix ADDR with 0x for hexadecimal, output is in same base as address.\n\n-f FILE File to operate on (default /dev/mem)\n--no-sync Don't open the file with O_SYNC (for cached access)"
+#define HELP_devmem "usage: devmem [-f FILE] ADDR [WIDTH [DATA...]]\n\nRead/write physical addresses. WIDTH is 1, 2, 4, or 8 bytes (default 4).\nPrefix ADDR with 0x for hexadecimal, output is in same base as address.\n\n-f FILE File to operate on (default /dev/mem)\n--no-sync Don't open the file with O_SYNC (for cached access)\n--no-mmap Don't mmap the file"
#define HELP_count "usage: count [-l]\n\n-l Long output (total bytes, human readable, transfer rate, elapsed time)\n\nCopy stdin to stdout, displaying simple progress indicator to stderr."
diff --git a/android/linux/generated/newtoys.h b/android/linux/generated/newtoys.h
index c41eb83f..e99f4f1c 100644
--- a/android/linux/generated/newtoys.h
+++ b/android/linux/generated/newtoys.h
@@ -60,7 +60,7 @@ USE_DEMO_MANY_OPTIONS(NEWTOY(demo_many_options, "ZYXWVUTSRQPONMLKJIHGFEDCBAzyxwv
USE_DEMO_NUMBER(NEWTOY(demo_number, "D#=3<3M#<0hcdbs", TOYFLAG_BIN))
USE_DEMO_SCANKEY(NEWTOY(demo_scankey, 0, TOYFLAG_BIN))
USE_DEMO_UTF8TOWC(NEWTOY(demo_utf8towc, 0, TOYFLAG_USR|TOYFLAG_BIN))
-USE_DEVMEM(NEWTOY(devmem, "<1(no-sync)f:", TOYFLAG_USR|TOYFLAG_SBIN))
+USE_DEVMEM(NEWTOY(devmem, "<1(no-sync)(no-mmap)f:", TOYFLAG_USR|TOYFLAG_SBIN))
USE_DF(NEWTOY(df, "HPkhit*a[-HPh]", TOYFLAG_BIN))
USE_DHCP(NEWTOY(dhcp, "V:H:F:x*r:O*A#<0=20T#<0=3t#<0=3s:p:i:SBRCaovqnbf", TOYFLAG_SBIN|TOYFLAG_ROOTONLY))
USE_DHCP6(NEWTOY(dhcp6, "r:A#<0T#<0t#<0s:p:i:SRvqnbf", TOYFLAG_SBIN|TOYFLAG_ROOTONLY))
diff --git a/android/mac/generated/flags.h b/android/mac/generated/flags.h
index 504dd782..59fd25af 100644
--- a/android/mac/generated/flags.h
+++ b/android/mac/generated/flags.h
@@ -641,13 +641,14 @@
#undef FOR_demo_utf8towc
#endif
-// devmem <1(no-sync)f:
+// devmem <1(no-sync)(no-mmap)f:
#undef OPTSTR_devmem
-#define OPTSTR_devmem "<1(no-sync)f:"
+#define OPTSTR_devmem "<1(no-sync)(no-mmap)f:"
#ifdef CLEANUP_devmem
#undef CLEANUP_devmem
#undef FOR_devmem
#undef FLAG_f
+#undef FLAG_no_mmap
#undef FLAG_no_sync
#endif
@@ -4547,7 +4548,8 @@
#define TT this.devmem
#endif
#define FLAG_f (FORCED_FLAG<<0)
-#define FLAG_no_sync (FORCED_FLAG<<1)
+#define FLAG_no_mmap (FORCED_FLAG<<1)
+#define FLAG_no_sync (FORCED_FLAG<<2)
#endif
#ifdef FOR_df
diff --git a/android/mac/generated/help.h b/android/mac/generated/help.h
index f25a0785..eccc159a 100644
--- a/android/mac/generated/help.h
+++ b/android/mac/generated/help.h
@@ -332,7 +332,7 @@
#define HELP_dos2unix "usage: dos2unix [FILE...]\n\nConvert newline format from dos \"\\r\\n\" to unix \"\\n\".\nIf no files listed copy from stdin, \"-\" is a synonym for stdin."
-#define HELP_devmem "usage: devmem [-f FILE] ADDR [WIDTH [DATA...]]\n\nRead/write physical addresses. WIDTH is 1, 2, 4, or 8 bytes (default 4).\nPrefix ADDR with 0x for hexadecimal, output is in same base as address.\n\n-f FILE File to operate on (default /dev/mem)\n--no-sync Don't open the file with O_SYNC (for cached access)"
+#define HELP_devmem "usage: devmem [-f FILE] ADDR [WIDTH [DATA...]]\n\nRead/write physical addresses. WIDTH is 1, 2, 4, or 8 bytes (default 4).\nPrefix ADDR with 0x for hexadecimal, output is in same base as address.\n\n-f FILE File to operate on (default /dev/mem)\n--no-sync Don't open the file with O_SYNC (for cached access)\n--no-mmap Don't mmap the file"
#define HELP_count "usage: count [-l]\n\n-l Long output (total bytes, human readable, transfer rate, elapsed time)\n\nCopy stdin to stdout, displaying simple progress indicator to stderr."
diff --git a/android/mac/generated/newtoys.h b/android/mac/generated/newtoys.h
index c41eb83f..e99f4f1c 100644
--- a/android/mac/generated/newtoys.h
+++ b/android/mac/generated/newtoys.h
@@ -60,7 +60,7 @@ USE_DEMO_MANY_OPTIONS(NEWTOY(demo_many_options, "ZYXWVUTSRQPONMLKJIHGFEDCBAzyxwv
USE_DEMO_NUMBER(NEWTOY(demo_number, "D#=3<3M#<0hcdbs", TOYFLAG_BIN))
USE_DEMO_SCANKEY(NEWTOY(demo_scankey, 0, TOYFLAG_BIN))
USE_DEMO_UTF8TOWC(NEWTOY(demo_utf8towc, 0, TOYFLAG_USR|TOYFLAG_BIN))
-USE_DEVMEM(NEWTOY(devmem, "<1(no-sync)f:", TOYFLAG_USR|TOYFLAG_SBIN))
+USE_DEVMEM(NEWTOY(devmem, "<1(no-sync)(no-mmap)f:", TOYFLAG_USR|TOYFLAG_SBIN))
USE_DF(NEWTOY(df, "HPkhit*a[-HPh]", TOYFLAG_BIN))
USE_DHCP(NEWTOY(dhcp, "V:H:F:x*r:O*A#<0=20T#<0=3t#<0=3s:p:i:SBRCaovqnbf", TOYFLAG_SBIN|TOYFLAG_ROOTONLY))
USE_DHCP6(NEWTOY(dhcp6, "r:A#<0T#<0t#<0s:p:i:SRvqnbf", TOYFLAG_SBIN|TOYFLAG_ROOTONLY))
diff --git a/toys/other/devmem.c b/toys/other/devmem.c
index 9f9a9e03..f37e8ef3 100644
--- a/toys/other/devmem.c
+++ b/toys/other/devmem.c
@@ -2,7 +2,7 @@
*
* Copyright 2019 The Android Open Source Project
-USE_DEVMEM(NEWTOY(devmem, "<1(no-sync)f:", TOYFLAG_USR|TOYFLAG_SBIN))
+USE_DEVMEM(NEWTOY(devmem, "<1(no-sync)(no-mmap)f:", TOYFLAG_USR|TOYFLAG_SBIN))
config DEVMEM
bool "devmem"
@@ -15,6 +15,7 @@ config DEVMEM
-f FILE File to operate on (default /dev/mem)
--no-sync Don't open the file with O_SYNC (for cached access)
+ --no-mmap Don't mmap the file
*/
#define FOR_devmem
@@ -62,32 +63,46 @@ void devmem_main(void)
flags = writing ? O_RDWR : O_RDONLY;
if (!FLAG(no_sync)) flags |= O_SYNC;
fd = xopen(TT.f ?: "/dev/mem", flags);
- map_off = addr & ~(page_size - 1ULL);
- map_len = (addr+bytes-map_off);
- map = xmmap(0, map_len, writing ? PROT_WRITE : PROT_READ, MAP_SHARED, fd,
- map_off);
- p = map + (addr & (page_size - 1));
- close(fd);
+ if (FLAG(no_mmap)) xlseek(fd, addr, SEEK_SET);
+ else {
+ map_off = addr & ~(page_size - 1ULL);
+ map_len = addr + (writing ? (toys.optc - 2) * bytes : bytes) - map_off;
+ map = xmmap(0, map_len, writing ? PROT_WRITE : PROT_READ, MAP_SHARED, fd,
+ map_off);
+ p = map + (addr & (page_size - 1));
+ close(fd);
+ }
} else p = (void *)addr;
// Not using peek()/poke() because registers care about size of read/write.
if (writing) {
for (int i = 2; i < toys.optc; i++) {
data = xatolu(toys.optargs[i], bytes);
- if (bytes==1) *(char *)p = data;
- else if (bytes==2) *(unsigned short *)p = data;
- else if (bytes==4) *(unsigned int *)p = data;
- else if (sizeof(long)==8 && bytes==8) *(unsigned long *)p = data;
- p += bytes;
+ if (FLAG(no_mmap)) {
+ xwrite(fd, &data, bytes);
+ xlseek(fd, bytes, SEEK_CUR);
+ } else {
+ if (bytes==1) *(char *)p = data;
+ else if (bytes==2) *(unsigned short *)p = data;
+ else if (bytes==4) *(unsigned int *)p = data;
+ else if (sizeof(long)==8 && bytes==8) *(unsigned long *)p = data;
+ p += bytes;
+ }
}
} else {
- if (bytes==1) data = *(char *)p;
- else if (bytes==2) data = *(unsigned short *)p;
- else if (bytes==4) data = *(unsigned int *)p;
- else if (sizeof(long)==8 && bytes==8) data = *(unsigned long *)p;
+ if (FLAG(no_mmap)) xread(fd, &data, bytes);
+ else {
+ if (bytes==1) data = *(char *)p;
+ else if (bytes==2) data = *(unsigned short *)p;
+ else if (bytes==4) data = *(unsigned int *)p;
+ else if (sizeof(long)==8 && bytes==8) data = *(unsigned long *)p;
+ }
printf((!strchr(*toys.optargs, 'x')) ? "%0*ld\n" : "0x%0*lx\n",
bytes*2, data);
}
- if (CFG_TOYBOX_FORK) munmap(map, map_len);
+ if (CFG_TOYBOX_FORK) {
+ if (FLAG(no_mmap)) close(fd);
+ else munmap(map, map_len);
+ }
}
--
2.47.0.105.g07ac214952-goog
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