[librm] Use libflat to enable A20 line on each real-to-protected transition

[gpxe.git] / src / arch / i386 / drivers / net / undiload.c

diff --git a/src/arch/i386/drivers/net/undiload.c b/src/arch/i386/drivers/net/undiload.c
index fc8d919..8271b50 100644 (file)
--- a/src/arch/i386/drivers/net/undiload.c
+++ b/src/arch/i386/drivers/net/undiload.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 

+FILE_LICENCE ( GPL2_OR_LATER );
+

 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>


@@ -36,11 +38,11 @@
  */
 
 /** Parameter block for calling UNDI loader */
  */
 
 /** Parameter block for calling UNDI loader */

-static struct s_UNDI_LOADER __data16 ( undi_loader );
+static struct s_UNDI_LOADER __bss16 ( undi_loader );

 #define undi_loader __use_data16 ( undi_loader )
 
 /** UNDI loader entry point */
 #define undi_loader __use_data16 ( undi_loader )
 
 /** UNDI loader entry point */

-static SEGOFF16_t __data16 ( undi_loader_entry );
+static SEGOFF16_t __bss16 ( undi_loader_entry );

 #define undi_loader_entry __use_data16 ( undi_loader_entry )
 
 /**
 #define undi_loader_entry __use_data16 ( undi_loader_entry )
 
 /**


@@ -56,6 +58,12 @@ int undi_load ( struct undi_device *undi, struct undi_rom *undirom ) {
        uint16_t exit;
        int rc;
 
        uint16_t exit;
        int rc;
 

+       /* Only one UNDI instance may be loaded at any given time */
+       if ( undi_loader_entry.segment ) {
+               DBG ( "UNDI %p cannot load multiple instances\n", undi );
+               return -EBUSY;
+       }
+

        /* Set up START_UNDI parameters */
        memset ( &undi_loader, 0, sizeof ( undi_loader ) );
        undi_loader.AX = undi->pci_busdevfn;
        /* Set up START_UNDI parameters */
        memset ( &undi_loader, 0, sizeof ( undi_loader ) );
        undi_loader.AX = undi->pci_busdevfn;


@@ -90,24 +98,16 @@ int undi_load ( struct undi_device *undi, struct undi_rom *undirom ) {
        undi_loader_entry = undirom->loader_entry;
        __asm__ __volatile__ ( REAL_CODE ( "pushw %%ds\n\t"
                                           "pushw %%ax\n\t"
        undi_loader_entry = undirom->loader_entry;
        __asm__ __volatile__ ( REAL_CODE ( "pushw %%ds\n\t"
                                           "pushw %%ax\n\t"

-                                          "lcall *%c2\n\t"
+                                          "lcall *undi_loader_entry\n\t"

                                           "addw $4, %%sp\n\t" )
                               : "=a" ( exit )
                                           "addw $4, %%sp\n\t" )
                               : "=a" ( exit )

-                              : "a" ( & __from_data16 ( undi_loader ) ),
-                                "p" ( & __from_data16 ( undi_loader_entry ) )
+                              : "a" ( __from_data16 ( &undi_loader ) )

                               : "ebx", "ecx", "edx", "esi", "edi", "ebp" );
 
                               : "ebx", "ecx", "edx", "esi", "edi", "ebp" );
 

-       /* UNDI API calls may rudely change the status of A20 and not
-        * bother to restore it afterwards.  Intel is known to be
-        * guilty of this.
-        *
-        * Note that we will return to this point even if A20 gets
-        * screwed up by the UNDI driver, because Etherboot always
-        * resides in an even megabyte of RAM.
-        */     
-       gateA20_set();
-

        if ( exit != PXENV_EXIT_SUCCESS ) {
        if ( exit != PXENV_EXIT_SUCCESS ) {

+               /* Clear entry point */
+               memset ( &undi_loader_entry, 0, sizeof ( undi_loader_entry ) );
+

                rc = -undi_loader.Status;
                if ( rc == 0 ) /* Paranoia */
                        rc = -EIO;
                rc = -undi_loader.Status;
                if ( rc == 0 ) /* Paranoia */
                        rc = -EIO;


@@ -150,6 +150,9 @@ int undi_unload ( struct undi_device *undi ) {
 
        DBGC ( undi, "UNDI %p unloading\n", undi );
 
 
        DBGC ( undi, "UNDI %p unloading\n", undi );
 

+       /* Clear entry point */
+       memset ( &undi_loader_entry, 0, sizeof ( undi_loader_entry ) );
+

        /* Erase signatures */
        if ( undi->pxenv.segment )
                put_real ( dead, undi->pxenv.segment, undi->pxenv.offset );
        /* Erase signatures */
        if ( undi->pxenv.segment )
                put_real ( dead, undi->pxenv.segment, undi->pxenv.offset );