+#ifdef RISCiX
+
+ /* Acorn's RISC-iX has a wacky way of initialising the position of the heap.
+ * There is a little table in crt0.o that is filled at link time with
+ * the min and current brk positions, among other things. When start
+ * runs, it copies the table to where these parameters live during
+ * execution. This data is in text space, so it cannot be modified here
+ * before saving the executable, so the data is written manually. In
+ * addition, the table does not have a label, and the nearest accessible
+ * label (mcount) is not prefixed with a '_', thus making it inaccessible
+ * from within C programs. To overcome this, emacs's executable is passed
+ * through the command 'nm %s | fgrep mcount' into a pipe, and the
+ * resultant output is then used to find the address of 'mcount'. As far as
+ * is possible to determine, in RISC-iX releases prior to 1.2, the negative
+ * offset of the table from mcount is 0x2c, whereas from 1.2 onwards it is
+ * 0x30. bss_end has been rounded up to page boundary. This solution is
+ * based on suggestions made by Kevin Welton and Steve Hunt of Acorn, and
+ * avoids the need for a custom version of crt0.o for emacs which has its
+ * table in data space.
+ */
+
+ {
+ char command[1024];
+ char errbuf[1024];
+ char address_text[32];
+ int proforma[4];
+ FILE *pfile;
+ char *temp_ptr;
+ char c;
+ int mcount_address, mcount_offset, count;
+ extern char *_execname;
+
+
+ /* The use of _execname is incompatible with RISCiX 1.1 */
+ sprintf (command, "nm %s | fgrep mcount", _execname);
+
+ if ( (pfile = popen(command, "r")) == NULL)
+ {
+ sprintf (errbuf, "Could not open pipe");
+ PERROR (errbuf);
+ }
+
+ count=0;
+ while ( ((c=getc(pfile)) != EOF) && (c != ' ') && (count < 31))
+ address_text[count++]=c;
+ address_text[count]=0;
+
+ if ((count == 0) || pclose(pfile) != NULL)
+ {
+ sprintf (errbuf, "Failed to execute the command '%s'\n", command);
+ PERROR (errbuf);
+ }
+
+ sscanf(address_text, "%x", &mcount_address);
+ ptr = (char *) unexec_text_start;
+ mcount_offset = (char *)mcount_address - ptr;
+
+#ifdef RISCiX_1_1
+#define EDATA_OFFSET 0x2c
+#else
+#define EDATA_OFFSET 0x30
+#endif
+
+ end = ptr + mcount_offset - EDATA_OFFSET;
+
+ write_segment (new, ptr, end);
+
+ proforma[0] = bss_end; /* becomes _edata */
+ proforma[1] = bss_end; /* becomes _end */
+ proforma[2] = bss_end; /* becomes _minbrk */
+ proforma[3] = bss_end; /* becomes _curbrk */
+
+ write (new, proforma, 16);
+
+ temp_ptr = ptr;
+ ptr = end + 16;
+ end = temp_ptr + hdr.a_text;
+
+ write_segment (new, ptr, end);
+ }
+
+#else /* !RISCiX */
HCoop / bpt / emacs.git / blobdiff