Add function for VDAT processing.
This CL is a user space counterpart of
http://codereview.chromium.org/6690023, which provided the
ability to retrieve buffers through chromeos_acpi driver.
The buffer contents is communicated as a multi line string
with each buffer byte represented as a two symbol hex
number. `crosstool', on the other has to map the buffer
contents into a certain binary structure. This CL add
conversion of the multiline string into a binary buffer and
also adds a temp. routine to dump the buffer contents on the
screen when `crosstool' is invoked.
Change-Id: I8dd3eb935332f9bc8769c71de0db302365f12d70
BUG=chromium-os:13069, chromium-os:13091
TEST=manual
- Install the new image on a target with firmware providing
the VDAT ACPI method.
- Run crosstool and watch for the last line:
vdat = 11 22 33 44 ff 1f 1c 40 ff 57 74 41 ff ff ff ff # Raw VDAT contents.
localhost tmp #
Review URL: http://codereview.chromium.org/6695012
diff --git a/host/lib/crossystem.c b/host/lib/crossystem.c
index 04dc975..9bea492 100644
--- a/host/lib/crossystem.c
+++ b/host/lib/crossystem.c
@@ -5,6 +5,10 @@
#include <stdio.h>
#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <ctype.h>
#include "host_common.h"
@@ -68,6 +72,7 @@
#define ACPI_FMAP_PATH ACPI_BASE_PATH "/FMAP"
#define ACPI_GPIO_PATH ACPI_BASE_PATH "/GPIO"
#define ACPI_VBNV_PATH ACPI_BASE_PATH "/VBNV"
+#define ACPI_VDAT_PATH ACPI_BASE_PATH "/VDAT"
/* Base name for GPIO files */
#define GPIO_BASE_PATH "/sys/class/gpio"
@@ -79,6 +84,12 @@
/* Filename for kernel command line */
#define KERNEL_CMDLINE_PATH "/proc/cmdline"
+/* A structure to contain buffer data retrieved from the ACPI. */
+typedef struct {
+ int buffer_size;
+ void* buffer;
+} AcpiBuffer;
+
/* Copy up to dest_size-1 characters from src to dest, ensuring null
termination (which strncpy() doesn't do). Returns the destination
@@ -284,6 +295,102 @@
return 0;
}
+/*
+ * Get buffer data from ACPI.
+ *
+ * Buffer data is expected to be represented by a file which is a text dump of
+ * the buffer, representing each byte by two hex numbers, space and newline
+ * separated.
+ *
+ * Input - ACPI file name to get data from.
+ *
+ * Output: a pointer to AcpiBuffer structure containing the binary
+ * representation of the data. The caller is responsible for
+ * deallocating the pointer, this will take care of both the structure
+ * and the buffer. Null in case of error.
+ */
+
+AcpiBuffer* VbGetBuffer(const char* filename)
+{
+ FILE* f = NULL;
+ char* file_buffer = NULL;
+ AcpiBuffer* acpi_buffer = NULL;
+ AcpiBuffer* return_value = NULL;
+
+ do {
+ struct stat fs;
+ unsigned char* output_ptr;
+ int rv, i, real_size;
+
+ rv = stat(filename, &fs);
+ if (rv || !S_ISREG(fs.st_mode))
+ break;
+
+ f = fopen(filename, "r");
+ if (!f)
+ break;
+
+ file_buffer = Malloc(fs.st_size + 1);
+ if (!file_buffer)
+ break;
+
+
+ real_size = fread(file_buffer, 1, fs.st_size, f);
+ if (!real_size)
+ break;
+
+ /* each byte in the output will replace two characters and a space in the
+ * input, so the output size does not exceed input side/3 (a little less
+ * if account for newline characters).
+ */
+ acpi_buffer = Malloc(sizeof(AcpiBuffer) + real_size/3);
+
+ if (!acpi_buffer)
+ break;
+
+ file_buffer[real_size] = '\0';
+
+ acpi_buffer->buffer = acpi_buffer + 1;
+ acpi_buffer->buffer_size = 0;
+ output_ptr = acpi_buffer->buffer;
+
+ /* process the file contents */
+ for (i = 0; i < real_size; i++) {
+ char* base, *end;
+
+ base = file_buffer + i;
+
+ if (!isxdigit(*base))
+ continue;
+
+ output_ptr[acpi_buffer->buffer_size++] = strtol(base, &end, 16) & 0xff;
+
+ if ((end - base) != 2)
+ /* Input file format error */
+ break;
+
+ i += 2; /* skip the second character and the following space */
+ }
+
+ if (i == real_size) {
+ /* all is well */
+ return_value = acpi_buffer;
+ acpi_buffer = NULL; /* prevent it from deallocating */
+ }
+ } while(0);
+
+ /* wrap up */
+ if (f)
+ fclose(f);
+
+ if (file_buffer)
+ Free(file_buffer);
+
+ if (acpi_buffer)
+ Free(acpi_buffer);
+
+ return return_value;
+}
/* Read an integer property from VbNvStorage.
*
@@ -565,6 +672,31 @@
return value;
}
+/* This function is just an example illustrating the use of VbGetBuffer(). It
+ * converts the binary contents of the buffer into a space delimetered hex
+ * string. It is expected to be replaced with a function which has knowledge
+ * of the buffer data structure.
+ */
+char* GetVdatBuffer(void)
+{
+ char* buffer, *src, *p;
+ int i;
+
+ AcpiBuffer* ab = VbGetBuffer(ACPI_VDAT_PATH);
+ if (!ab)
+ return NULL;
+
+ buffer = Malloc(ab->buffer_size * 3 + 2);
+ p = buffer;
+ src = ab->buffer;
+ for (i = 0; i < ab->buffer_size; i++) {
+ snprintf(p, 4, " %2.2x", *src++);
+ p += 3;
+ }
+ *p = '\0';
+ Free(ab);
+ return buffer;
+}
/* Read a system property string into a destination buffer of the specified
* size.
@@ -609,6 +741,8 @@
default:
return NULL;
}
+ } else if (!strcasecmp(name, "vdat")) {
+ return GetVdatBuffer();
} else
return NULL;
}
diff --git a/utility/crossystem_main.c b/utility/crossystem_main.c
index 90ad718..4d6cd48 100644
--- a/utility/crossystem_main.c
+++ b/utility/crossystem_main.c
@@ -49,6 +49,7 @@
{"recovery_request", 0, 1, "Recovery mode request (writable)"},
{"dbg_reset", 0, 1, "Debug reset mode request (writable)"},
{"fwb_tries", 0, 1, "Try firmware B count (writable)"},
+ {"vdat", 1, 0, "Raw VDAT contents."},
/* TODO: implement the following:
* nvram_cleared