Dan Mick wrote:
> /dev/mem doesn't access all of physical memory on Solaris x86.
>
> At present, the best substitute is the undocumented /dev/xsvc.
Thanks. I tried /dev/xsvc with lseek+read, seems it is not lseekable.
I'll try mmap later.
>
> Jike Song wrote:
>> Hi,
>>
>> I'm trying to port x86info to Solaris/OpenSolaris. However, I encountered
>> a problem wrt. MP tables.
>> x86info accepts a "-mp" option, and will dump the MP tables via lseek/read
>> /dev/mem.
>>
>> From the MultiProcessor Specification 1.4, this table should be probed as
>> following:
>>
>> The MP Floating Pointer Structure. This structure contains a physical
>> address pointer to the
>> MP configuration table and other MP feature information bytes. When present,
>> this structure
>> indicates that the system conforms to the MP specification. This structure
>> must be stored in at
>> least one of the following memory locations, because the operating system
>> searches for the MP
>> floating pointer structure in the order described below:
>> a. In the first kilobyte of Extended BIOS Data Area (EBDA), or
>> b. Within the last kilobyte of system base memory (e.g., 639K-640K for
>> systems with 640
>> KB of base memory or 511K-512K for systems with 512 KB of base memory)
>> if the
>> EBDA segment is undefined, or
>> c. In the BIOS ROM address space between 0F0000h and 0FFFFFh.
>>
>>
>> But when you run x86info as root, the reading always fails:
>>
>> [js226...@git x86info]$ sudo x86info
>> x86info v1.21. Dave Jones 2001-2007
>> Feedback to <da...@redhat.com>.
>>
>> readEntry: Bad address
>> Found 4 cpus[js226...@git x86info]$
>>
>>
>> I wrote a program to do what the function apic_probe() of x86info project
>> does
>>
>> /* filename: mem.c
>> *
>> * This is a silly program does what the function apic_probe() of x86info
>> project does:
>> *
>> * -> open /dev/mem
>> * -> seek where the MP config table is
>> * -> read 1024 bytes for EBDA
>> */
>> #include <stdio.h>
>> #include <stdint.h>
>> #include <stdlib.h>
>> #include <sys/types.h>
>> #include <sys/stat.h>
>> #include <fcntl.h>
>> #include <unistd.h>
>>
>> typedef unsigned long vm_offset_t;
>> #define BIOS_SIZE 0x10000
>> #define ONE_KBYTE 1024
>>
>>
>>
>> int main(void)
>> {
>> uint16_t segment;
>> vm_offset_t target;
>> unsigned int buffer[BIOS_SIZE];
>>
>> int fd = open("/dev/mem", O_RDONLY);
>> if (fd == -1) {
>> perror("open");
>> exit(EXIT_FAILURE);
>> }
>>
>> if (lseek(fd, 0x040e, SEEK_SET) == (off_t)-1 ) {
>> perror("lseek");
>> exit(EXIT_FAILURE);
>> }
>>
>> if (read(fd, &segment, 2) == -1) {
>> perror("read");
>> exit(EXIT_FAILURE);
>> }
>>
>> printf("%hx\n", segment);
>>
>> if (segment) {
>> target = (vm_offset_t)segment << 4;
>> if (lseek(fd, target, SEEK_SET) == (off_t)-1 ) {
>> perror("lseek");
>> exit(EXIT_FAILURE);
>> }
>>
>> if (read(fd, buffer, ONE_KBYTE) == -1) {
>> perror("read");
>> exit(EXIT_FAILURE);
>> } else
>> printf("read of 1024 bytes of EBDA succeeded\n");
>> }
>>
>>
>> return 0;
>> }
>>
>>
>> [js226...@git ~]$ sudo ./mem
>> 9ec0
>> read: Bad address
>>
>>
>> Besides, I have test x86info in both Solaris/Linux on a machine. Linux's
>> /dev/mem driver handled this reading correctly.
>>
>> Any clues?
>>
>>
>>
>
--
Thanks,
Jike Song, SW Engineer
Sun Microsystems China(ERI)
Tel: (86-10)62673147
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