add qemu-fwcfg

apps/qemu-fwcfg.c

@@ -0,0 +1,158 @@
+/*
+ * Tool for reading QEMU fwcfg values.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <getopt.h>
+
+unsigned short inports(unsigned short _port) {
+	unsigned short rv;
+	asm volatile ("inw %1, %0" : "=a" (rv) : "dN" (_port));
+	return rv;
+}
+
+void outports(unsigned short _port, unsigned short _data) {
+	asm volatile ("outw %1, %0" : : "dN" (_port), "a" (_data));
+}
+
+unsigned int inportl(unsigned short _port) {
+	unsigned int rv;
+	asm volatile ("inl %%dx, %%eax" : "=a" (rv) : "dN" (_port));
+	return rv;
+}
+
+void outportl(unsigned short _port, unsigned int _data) {
+	asm volatile ("outl %%eax, %%dx" : : "dN" (_port), "a" (_data));
+}
+
+unsigned char inportb(unsigned short _port) {
+	unsigned char rv;
+	asm volatile ("inb %1, %0" : "=a" (rv) : "dN" (_port));
+	return rv;
+}
+
+void outportb(unsigned short _port, unsigned char _data) {
+	asm volatile ("outb %1, %0" : : "dN" (_port), "a" (_data));
+}
+
+void outportsm(unsigned short port, unsigned char * data, unsigned long size) {
+	asm volatile ("rep outsw" : "+S" (data), "+c" (size) : "d" (port));
+}
+
+void inportsm(unsigned short port, unsigned char * data, unsigned long size) {
+	asm volatile ("rep insw" : "+D" (data), "+c" (size) : "d" (port) : "memory");
+}
+
+void swap_bytes(void * in, int count) {
+	char * bytes = in;
+	if (count == 4) {
+		uint32_t * t = in;
+		*t = (bytes[0] << 24) | (bytes[1] << 12) | (bytes[2] << 8) | bytes[3];
+	} else if (count == 2) {
+		uint16_t * t = in;
+		*t = (bytes[0] << 8) | bytes[1];
+	}
+}
+
+struct fw_cfg_file {
+	uint32_t size;
+	uint16_t select;
+	uint16_t reserved;
+	char name[56];
+};
+
+int usage(char * argv[]) {
+	printf(
+			"usage: %s [-?ln] [config name]\n"
+			"\n"
+			" -l     \033[3mlist available config entries\033[0m\n"
+			" -n     \033[3mdon't print a new line after image\033[0m\n"
+			" -?     \033[3mshow this help text\033[0m\n"
+			"\n", argv[0]);
+	return 1;
+}
+
+int main(int argc, char * argv[]) {
+
+	int opt = 0;
+	int list = 0;
+	int no_newline = 0;
+
+	while ((opt = getopt(argc, argv, "?ln")) != -1) {
+		switch (opt) {
+			case '?':
+				return usage(argv);
+			case 'n':
+				no_newline = 1;
+				break;
+			case 'l':
+				list = 1;
+				break;
+		}
+	}
+
+	if (optind >= argc && !list) {
+		return usage(argv);
+	}
+
+	outports(0x510, 0x0000);
+	if (inportb(0x511) != 'Q' ||
+		inportb(0x511) != 'E' ||
+		inportb(0x511) != 'M' ||
+		inportb(0x511) != 'U') {
+		fprintf(stderr, "%s: this doesn't seem to be qemu\n", argv[0]);
+	}
+
+	uint32_t count = 0;
+	uint8_t * bytes = (uint8_t *)&count;
+	outports(0x510,0x0019);
+	for (int i = 0; i < 4; ++i) {
+		bytes[i] = inportb(0x511);
+	}
+	swap_bytes(&count, 4);
+
+	int found = 0;
+	struct fw_cfg_file file;
+	uint8_t * tmp = (uint8_t *)&file;
+
+	for (unsigned int i = 0; i < count; ++i) {
+		for (unsigned int j = 0; j < sizeof(struct fw_cfg_file); ++j) {
+			tmp[j] = inportb(0x511);
+		}
+
+		swap_bytes(&file.size, 4);
+		swap_bytes(&file.select, 2);
+
+		if (list) {
+			fprintf(stdout, "%s (%d byte%s)\n", file.name, (int)file.size, file.size == 1 ? "" : "s");
+		} else {
+			if (!strcmp(file.name, argv[optind])) {
+				found = 1;
+				break;
+			}
+		}
+	}
+
+	if (found) {
+		outports(0x510, file.select);
+		char * tmp = malloc(file.size);
+		for (unsigned int i = 0; i < 32 && i < file.size; ++i) {
+			tmp[i] = inportb(0x511);
+		}
+		fwrite(tmp, 1, file.size, stdout);
+
+		if (!no_newline) {
+			fprintf(stdout, "\n");
+		}
+	} else if (!list) {
+		fprintf(stderr, "%s: config option not found\n", argv[0]);
+		return 1;
+	}
+
+	return 0;
+}