28 lines
740 B
C
28 lines
740 B
C
#include <stdio.h>
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#include <inttypes.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <limits.h>
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#include "pci.h"
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char pci_path[PATH_MAX] = ".";
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__attribute__((stdcall)) uint32_t pci_read(uint32_t bus, uint32_t dev,
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uint32_t fun, uint32_t offset,
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size_t len) {
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char path[PATH_MAX*2];
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uint32_t value = 0;
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sprintf(path, "%s/%4.4x:%2.2x:%2.2x.%u/config", pci_path, 0, bus, dev, fun);
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int fd = open(path, O_RDONLY);
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if (!fd) {
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// TODO: report an error
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return UINT32_MAX;
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}
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lseek(fd, offset, SEEK_SET);
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read(fd, &value, len);
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close(fd);
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return value;
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}
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