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-rw-r--r--Documentation/arm/SH-Mobile/vrl4.c169
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diff --git a/Documentation/arm/SH-Mobile/vrl4.c b/Documentation/arm/SH-Mobile/vrl4.c
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+/*
+ * vrl4 format generator
+ *
+ * Copyright (C) 2010 Simon Horman
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+/*
+ * usage: vrl4 < zImage > out
+ * dd if=out of=/dev/sdx bs=512 seek=1 # Write the image to sector 1
+ *
+ * Reads a zImage from stdin and writes a vrl4 image to stdout.
+ * In practice this means writing a padded vrl4 header to stdout followed
+ * by the zImage.
+ *
+ * The padding places the zImage at ALIGN bytes into the output.
+ * The vrl4 uses ALIGN + START_BASE as the start_address.
+ * This is where the mask ROM will jump to after verifying the header.
+ *
+ * The header sets copy_size to min(sizeof(zImage), MAX_BOOT_PROG_LEN) + ALIGN.
+ * That is, the mask ROM will load the padded header (ALIGN bytes)
+ * And then MAX_BOOT_PROG_LEN bytes of the image, or the entire image,
+ * whichever is smaller.
+ *
+ * The zImage is not modified in any way.
+ */
+
+#define _BSD_SOURCE
+#include <endian.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <errno.h>
+
+struct hdr {
+ uint32_t magic1;
+ uint32_t reserved1;
+ uint32_t magic2;
+ uint32_t reserved2;
+ uint16_t copy_size;
+ uint16_t boot_options;
+ uint32_t reserved3;
+ uint32_t start_address;
+ uint32_t reserved4;
+ uint32_t reserved5;
+ char reserved6[308];
+};
+
+#define DECLARE_HDR(h) \
+ struct hdr (h) = { \
+ .magic1 = htole32(0xea000000), \
+ .reserved1 = htole32(0x56), \
+ .magic2 = htole32(0xe59ff008), \
+ .reserved3 = htole16(0x1) }
+
+/* Align to 512 bytes, the MMCIF sector size */
+#define ALIGN_BITS 9
+#define ALIGN (1 << ALIGN_BITS)
+
+#define START_BASE 0xe55b0000
+
+/*
+ * With an alignment of 512 the header uses the first sector.
+ * There is a 128 sector (64kbyte) limit on the data loaded by the mask ROM.
+ * So there are 127 sectors left for the boot programme. But in practice
+ * Only a small portion of a zImage is needed, 16 sectors should be more
+ * than enough.
+ *
+ * Note that this sets how much of the zImage is copied by the mask ROM.
+ * The entire zImage is present after the header and is loaded
+ * by the code in the boot program (which is the first portion of the zImage).
+ */
+#define MAX_BOOT_PROG_LEN (16 * 512)
+
+#define ROUND_UP(x) ((x + ALIGN - 1) & ~(ALIGN - 1))
+
+ssize_t do_read(int fd, void *buf, size_t count)
+{
+ size_t offset = 0;
+ ssize_t l;
+
+ while (offset < count) {
+ l = read(fd, buf + offset, count - offset);
+ if (!l)
+ break;
+ if (l < 0) {
+ if (errno == EAGAIN || errno == EWOULDBLOCK)
+ continue;
+ perror("read");
+ return -1;
+ }
+ offset += l;
+ }
+
+ return offset;
+}
+
+ssize_t do_write(int fd, const void *buf, size_t count)
+{
+ size_t offset = 0;
+ ssize_t l;
+
+ while (offset < count) {
+ l = write(fd, buf + offset, count - offset);
+ if (l < 0) {
+ if (errno == EAGAIN || errno == EWOULDBLOCK)
+ continue;
+ perror("write");
+ return -1;
+ }
+ offset += l;
+ }
+
+ return offset;
+}
+
+ssize_t write_zero(int fd, size_t len)
+{
+ size_t i = len;
+
+ while (i--) {
+ const char x = 0;
+ if (do_write(fd, &x, 1) < 0)
+ return -1;
+ }
+
+ return len;
+}
+
+int main(void)
+{
+ DECLARE_HDR(hdr);
+ char boot_program[MAX_BOOT_PROG_LEN];
+ size_t aligned_hdr_len, alligned_prog_len;
+ ssize_t prog_len;
+
+ prog_len = do_read(0, boot_program, sizeof(boot_program));
+ if (prog_len <= 0)
+ return -1;
+
+ aligned_hdr_len = ROUND_UP(sizeof(hdr));
+ hdr.start_address = htole32(START_BASE + aligned_hdr_len);
+ alligned_prog_len = ROUND_UP(prog_len);
+ hdr.copy_size = htole16(aligned_hdr_len + alligned_prog_len);
+
+ if (do_write(1, &hdr, sizeof(hdr)) < 0)
+ return -1;
+ if (write_zero(1, aligned_hdr_len - sizeof(hdr)) < 0)
+ return -1;
+
+ if (do_write(1, boot_program, prog_len) < 0)
+ return 1;
+
+ /* Write out the rest of the kernel */
+ while (1) {
+ prog_len = do_read(0, boot_program, sizeof(boot_program));
+ if (prog_len < 0)
+ return 1;
+ if (prog_len == 0)
+ break;
+ if (do_write(1, boot_program, prog_len) < 0)
+ return 1;
+ }
+
+ return 0;
+}