[uClibc][PATCH] MIPS dynamic loader patch...

[Steven J. Hill]

Greetings.

This patch gets the MIPS dynamic loader to the point where it
correctly reads the number of command line arguments, the
environment variables and auxillary vector table. It also gets
the value of the GOT, although it is not currently correct
as any dereference of the GOT causes a SEGFAULT. I'm understanding
things better, so it's just a matter of time until bootstrap is
working. Please apply.

-Steve


diff -urN uclibc/ldso/ldso/ldso.c uclibc-patched/ldso/ldso/ldso.c
--- uclibc/ldso/ldso/ldso.c	Thu Mar 21 11:39:07 2002
+++ uclibc-patched/ldso/ldso/ldso.c	Fri Mar 29 15:29:30 2002
@@ -223,7 +223,7 @@
 	/* First obtain the information on the stack that tells us more about
 	   what binary is loaded, where it is loaded, etc, etc */
 	GET_ARGV(aux_dat, args);
-#if defined(__arm__)
+#if defined(__arm__) || defined(__mips__)
 	aux_dat += 1;
 #endif
 	argc = *(aux_dat - 1);
@@ -259,7 +259,7 @@
 	/* Check the ELF header to make sure everything looks ok.  */
 	if (!header || header->e_ident[EI_CLASS] != ELFCLASS32 ||
 		header->e_ident[EI_VERSION] != EV_CURRENT
-#ifndef __powerpc__
+#if !defined(__powerpc__) && !defined(__mips__)
 		|| _dl_strncmp((void *) header, ELFMAGIC, SELFMAG) != 0
 #endif
 		) {
@@ -286,6 +286,8 @@
   __asm__("\tmov %0, r10\n\t":"=r"(got));
 #elif defined(__powerpc__)
   __asm__("\tbl _GLOBAL_OFFSET_TABLE_-4 at local\n\t":"=l"(got));
+#elif defined(__mips__)
+  __asm__("\tmove %0, $28\n\t":"=r"(got));
 #else
 	/* Do things the slow way in C */
 	{
diff -urN uclibc/ldso/ldso/mips/boot1_arch.h uclibc-patched/ldso/ldso/mips/boot1_arch.h
--- uclibc/ldso/ldso/mips/boot1_arch.h	Wed Dec 31 18:00:00 1969
+++ uclibc-patched/ldso/ldso/mips/boot1_arch.h	Fri Mar 29 15:29:30 2002
@@ -0,0 +1,32 @@
+/* Any assmbly language/system dependent hacks needed to setup boot1.c so it
+ * will work as expected and cope with whatever platform specific wierdness is
+ * needed for this architecture.  See arm/boot1_arch.h for an example of what
+ * can be done.
+ */
+
+asm("
+	.text
+	.globl _dl_boot
+_dl_boot:
+	.set noreorder
+	bltzal $0, 0f
+	nop
+0:	.cpload $31
+	.set reorder
+	# i386 ABI book says that the first entry of GOT holds
+	# the address of the dynamic structure. Though MIPS ABI
+	# doesn't say nothing about this, I emulate this here.
+	la $4, _DYNAMIC
+	# Subtract OFFSET_GP_GOT
+	sw $4, -0x7ff0($28)
+	move $4, $29
+	la $8, coff
+	bltzal $8, coff
+coff:	subu $8, $31, $8
+	la $25, _dl_boot2
+	addu $25, $8
+	jalr $25
+");
+
+#define _dl_boot _dl_boot2
+#define DL_BOOT(X)   static void __attribute__ ((unused)) _dl_boot (X)
diff -urN uclibc/ldso/ldso/mips/ld_syscalls.h uclibc-patched/ldso/ldso/mips/ld_syscalls.h
--- uclibc/ldso/ldso/mips/ld_syscalls.h	Tue Mar 19 11:05:51 2002
+++ uclibc-patched/ldso/ldso/mips/ld_syscalls.h	Tue Mar 26 10:40:29 2002
@@ -4,6 +4,12 @@
  * Linux/MIPS 2.4.17 version kernel.
  */
 
+#ifndef _SYS_STAT_H
+#define _SYS_STAT_H
+
+#define new_stat stat
+#include <asm/stat.h>
+
 #define __NR_SYSCALL_BASE		4000
 
 #define __NR_exit			(__NR_SYSCALL_BASE +   1)
@@ -135,3 +141,5 @@
 		return (type) __v0; \
 	return (type) -1; \
 }
+
+#endif