#include <unistd.h>
#include <sys/utsname.h>
#include <io.h>
-/* breakpoint.h defines `disable' which is an enum member. */
-#define disable interrup_disable
#include <dos.h>
-#undef disable
#include <dpmi.h>
#include <go32.h>
+#include <sys/farptr.h>
#include <debug/v2load.h>
#include <debug/dbgcom.h>
#if __DJGPP_MINOR__ > 2
jmp_buf start_state;
char *cmdline;
char **env_save = environ;
+ size_t cmdlen;
/* If no exec file handed to us, get it from the exec-file command -- with
a good, common error message if none is specified. */
else
child_cmd.command = xstrdup (args);
- cmdline = (char *) alloca (strlen (args) + 4);
- cmdline[0] = strlen (args);
+ cmdlen = strlen (args);
+ /* v2loadimage passes command lines via DOS memory, so it cannot
+ possibly handle commands longer than 1MB. */
+ if (cmdlen > 1024*1024)
+ error ("Command line too long.");
+
+ cmdline = xmalloc (cmdlen + 4);
strcpy (cmdline + 1, args);
- cmdline[strlen (args) + 1] = 13;
+ /* If the command-line length fits into DOS 126-char limits, use the
+ DOS command tail format; otherwise, tell v2loadimage to pass it
+ through a buffer in conventional memory. */
+ if (cmdlen < 127)
+ {
+ cmdline[0] = strlen (args);
+ cmdline[cmdlen + 1] = 13;
+ }
+ else
+ cmdline[0] = 0xff; /* signal v2loadimage it's a long command */
environ = env;
exit (1);
}
environ = env_save;
+ xfree (cmdline);
edi_init (start_state);
#if __DJGPP_MINOR__ < 3
read_memory_region (unsigned long addr, void *dest, size_t len)
{
unsigned long dos_ds_limit = __dpmi_get_segment_limit (_dos_ds);
+ int retval = 1;
/* For the low memory, we can simply use _dos_ds. */
if (addr <= dos_ds_limit - len)
be able to access that memory. */
int sel = __dpmi_allocate_ldt_descriptors (1);
- if (sel <= 0
- || __dpmi_set_segment_base_address (sel, addr) == -1
- || __dpmi_set_segment_limit (sel, len - 1) == -1)
- return 0;
- movedata (sel, 0, _my_ds (), (unsigned)dest, len);
- __dpmi_free_ldt_descriptor (sel);
+ if (sel <= 0)
+ retval = 0;
+ else
+ {
+ int access_rights = __dpmi_get_descriptor_access_rights (sel);
+ size_t segment_limit = len - 1;
+
+ /* Make sure the crucial bits in the descriptor access
+ rights are set correctly. Some DPMI providers might barf
+ if we set the segment limit to something that is not an
+ integral multiple of 4KB pages if the granularity bit is
+ not set to byte-granular, even though the DPMI spec says
+ it's the host's responsibility to set that bit correctly. */
+ if (len > 1024 * 1024)
+ {
+ access_rights |= 0x8000;
+ /* Page-granular segments should have the low 12 bits of
+ the limit set. */
+ segment_limit |= 0xfff;
+ }
+ else
+ access_rights &= ~0x8000;
+
+ if (__dpmi_set_segment_base_address (sel, addr) != -1
+ && __dpmi_set_descriptor_access_rights (sel, access_rights) != -1
+ && __dpmi_set_segment_limit (sel, segment_limit) != -1
+ /* W2K silently fails to set the segment limit, leaving
+ it at zero; this test avoids the resulting crash. */
+ && __dpmi_get_segment_limit (sel) >= segment_limit)
+ movedata (sel, 0, _my_ds (), (unsigned)dest, len);
+ else
+ retval = 0;
+
+ __dpmi_free_ldt_descriptor (sel);
+ }
}
- return 1;
+ return retval;
}
/* Get a segment descriptor stored at index IDX in the descriptor
{
idt_entry = parse_and_eval_long (arg);
if (idt_entry < 0)
- error ("Invalid (negative) IDT entry 0x%03x.", idt_entry);
+ error ("Invalid (negative) IDT entry %d.", idt_entry);
}
}
}
}
+/* Cached linear address of the base of the page directory. For
+ now, available only under CWSDPMI. Code based on ideas and
+ suggestions from Charles Sandmann <sandmann@clio.rice.edu>. */
+static unsigned long pdbr;
+
+static unsigned long
+get_cr3 (void)
+{
+ unsigned offset;
+ unsigned taskreg;
+ unsigned long taskbase, cr3;
+ struct dtr_reg gdtr;
+
+ if (pdbr > 0 && pdbr <= 0xfffff)
+ return pdbr;
+
+ /* Get the linear address of GDT and the Task Register. */
+ __asm__ __volatile__ ("sgdt %0" : "=m" (gdtr) : /* no inputs */ );
+ __asm__ __volatile__ ("str %0" : "=m" (taskreg) : /* no inputs */ );
+
+ /* Task Register is a segment selector for the TSS of the current
+ task. Therefore, it can be used as an index into the GDT to get
+ at the segment descriptor for the TSS. To get the index, reset
+ the low 3 bits of the selector (which give the CPL). Add 2 to the
+ offset to point to the 3 low bytes of the base address. */
+ offset = gdtr.base + (taskreg & 0xfff8) + 2;
+
+
+ /* CWSDPMI's task base is always under the 1MB mark. */
+ if (offset > 0xfffff)
+ return 0;
+
+ _farsetsel (_dos_ds);
+ taskbase = _farnspeekl (offset) & 0xffffffU;
+ taskbase += _farnspeekl (offset + 2) & 0xff000000U;
+ if (taskbase > 0xfffff)
+ return 0;
+
+ /* CR3 (a.k.a. PDBR, the Page Directory Base Register) is stored at
+ offset 1Ch in the TSS. */
+ cr3 = _farnspeekl (taskbase + 0x1c) & ~0xfff;
+ if (cr3 > 0xfffff)
+ {
+#if 0 /* not fully supported yet */
+ /* The Page Directory is in UMBs. In that case, CWSDPMI puts
+ the first Page Table right below the Page Directory. Thus,
+ the first Page Table's entry for its own address and the Page
+ Directory entry for that Page Table will hold the same
+ physical address. The loop below searches the entire UMB
+ range of addresses for such an occurence. */
+ unsigned long addr, pte_idx;
+
+ for (addr = 0xb0000, pte_idx = 0xb0;
+ pte_idx < 0xff;
+ addr += 0x1000, pte_idx++)
+ {
+ if (((_farnspeekl (addr + 4 * pte_idx) & 0xfffff027) ==
+ (_farnspeekl (addr + 0x1000) & 0xfffff027))
+ && ((_farnspeekl (addr + 4 * pte_idx + 4) & 0xfffff000) == cr3))
+ {
+ cr3 = addr + 0x1000;
+ break;
+ }
+ }
+#endif
+
+ if (cr3 > 0xfffff)
+ cr3 = 0;
+ }
+
+ return cr3;
+}
+
+/* Return the N'th Page Directory entry. */
+static unsigned long
+get_pde (int n)
+{
+ unsigned long pde = 0;
+
+ if (pdbr && n >= 0 && n < 1024)
+ {
+ pde = _farpeekl (_dos_ds, pdbr + 4*n);
+ }
+ return pde;
+}
+
+/* Return the N'th entry of the Page Table whose Page Directory entry
+ is PDE. */
+static unsigned long
+get_pte (unsigned long pde, int n)
+{
+ unsigned long pte = 0;
+
+ /* pde & 0x80 tests the 4MB page bit. We don't support 4MB
+ page tables, for now. */
+ if ((pde & 1) && !(pde & 0x80) && n >= 0 && n < 1024)
+ {
+ pde &= ~0xfff; /* clear non-address bits */
+ pte = _farpeekl (_dos_ds, pde + 4*n);
+ }
+ return pte;
+}
+
+/* Display a Page Directory or Page Table entry. IS_DIR, if non-zero,
+ says this is a Page Directory entry. If FORCE is non-zero, display
+ the entry even if its Present flag is off. OFF is the offset of the
+ address from the page's base address. */
+static void
+display_ptable_entry (unsigned long entry, int is_dir, int force, unsigned off)
+{
+ if ((entry & 1) != 0)
+ {
+ printf_filtered ("Base=0x%05lx000", entry >> 12);
+ if ((entry & 0x100) && !is_dir)
+ puts_filtered (" Global");
+ if ((entry & 0x40) && !is_dir)
+ puts_filtered (" Dirty");
+ printf_filtered (" %sAcc.", (entry & 0x20) ? "" : "Not-");
+ printf_filtered (" %sCached", (entry & 0x10) ? "" : "Not-");
+ printf_filtered (" Write-%s", (entry & 8) ? "Thru" : "Back");
+ printf_filtered (" %s", (entry & 4) ? "Usr" : "Sup");
+ printf_filtered (" Read-%s", (entry & 2) ? "Write" : "Only");
+ if (off)
+ printf_filtered (" +0x%x", off);
+ puts_filtered ("\n");
+ }
+ else if (force)
+ printf_filtered ("Page%s not present or not supported; value=0x%lx.\n",
+ is_dir ? " Table" : "", entry >> 1);
+}
+
+static void
+go32_pde (char *arg, int from_tty)
+{
+ long pde_idx = -1, i;
+
+ if (arg && *arg)
+ {
+ while (*arg && isspace(*arg))
+ arg++;
+
+ if (*arg)
+ {
+ pde_idx = parse_and_eval_long (arg);
+ if (pde_idx < 0 || pde_idx >= 1024)
+ error ("Entry %ld is outside valid limits [0..1023].", pde_idx);
+ }
+ }
+
+ pdbr = get_cr3 ();
+ if (!pdbr)
+ puts_filtered ("Access to Page Directories is not supported on this system.\n");
+ else if (pde_idx >= 0)
+ display_ptable_entry (get_pde (pde_idx), 1, 1, 0);
+ else
+ for (i = 0; i < 1024; i++)
+ display_ptable_entry (get_pde (i), 1, 0, 0);
+}
+
+/* A helper function to display entries in a Page Table pointed to by
+ the N'th entry in the Page Directory. If FORCE is non-zero, say
+ something even if the Page Table is not accessible. */
+static void
+display_page_table (long n, int force)
+{
+ unsigned long pde = get_pde (n);
+
+ if ((pde & 1) != 0)
+ {
+ int i;
+
+ printf_filtered ("Page Table pointed to by Page Directory entry 0x%lx:\n", n);
+ for (i = 0; i < 1024; i++)
+ display_ptable_entry (get_pte (pde, i), 0, 0, 0);
+ puts_filtered ("\n");
+ }
+ else if (force)
+ printf_filtered ("Page Table not present; value=0x%lx.\n", pde >> 1);
+}
+
+static void
+go32_pte (char *arg, int from_tty)
+{
+ long pde_idx = -1, i;
+
+ if (arg && *arg)
+ {
+ while (*arg && isspace(*arg))
+ arg++;
+
+ if (*arg)
+ {
+ pde_idx = parse_and_eval_long (arg);
+ if (pde_idx < 0 || pde_idx >= 1024)
+ error ("Entry %d is outside valid limits [0..1023].", pde_idx);
+ }
+ }
+
+ pdbr = get_cr3 ();
+ if (!pdbr)
+ puts_filtered ("Access to Page Tables is not supported on this system.\n");
+ else if (pde_idx >= 0)
+ display_page_table (pde_idx, 1);
+ else
+ for (i = 0; i < 1024; i++)
+ display_page_table (i, 0);
+}
+
+static void
+go32_pte_for_address (char *arg, int from_tty)
+{
+ CORE_ADDR addr = 0, i;
+
+ if (arg && *arg)
+ {
+ while (*arg && isspace(*arg))
+ arg++;
+
+ if (*arg)
+ addr = parse_and_eval_address (arg);
+ }
+ if (!addr)
+ error_no_arg ("linear address");
+
+ pdbr = get_cr3 ();
+ if (!pdbr)
+ puts_filtered ("Access to Page Tables is not supported on this system.\n");
+ else
+ {
+ int pde_idx = (addr >> 22) & 0x3ff;
+ int pte_idx = (addr >> 12) & 0x3ff;
+ unsigned offs = addr & 0xfff;
+
+ printf_filtered ("Page Table entry for address 0x%llx:\n",
+ (unsigned long long)addr);
+ display_ptable_entry (get_pte (get_pde (pde_idx), pte_idx), 0, 1, offs);
+ }
+}
+
static struct cmd_list_element *info_dos_cmdlist = NULL;
static void
"Display entries in the IDT (Interrupt Descriptor Table).\n"
"Entry number (an expression) as an argument means display only that entry.",
&info_dos_cmdlist);
+ add_cmd ("pde", class_info, go32_pde,
+ "Display entries in the Page Directory.\n"
+ "Entry number (an expression) as an argument means display only that entry.",
+ &info_dos_cmdlist);
+ add_cmd ("pte", class_info, go32_pte,
+ "Display entries in Page Tables.\n"
+ "Entry number (an expression) as an argument means display only entries\n"
+ "from the Page Table pointed to by the specified Page Directory entry.",
+ &info_dos_cmdlist);
+ add_cmd ("address-pte", class_info, go32_pte_for_address,
+ "Display a Page Table entry for a linear address.\n"
+ "The address argument must be a linear address, after adding to\n"
+ "it the base address of the appropriate segment.\n"
+ "The base address of variables and functions in the debuggee's data\n"
+ "or code segment is stored in the variable __djgpp_base_address,\n"
+ "so use `__djgpp_base_address + (char *)&var' as the argument.\n"
+ "For other segments, look up their base address in the output of\n"
+ "the `info dos ldt' command.",
+ &info_dos_cmdlist);
}
pid_t
projects / deliverable / binutils-gdb.git / blobdiff