From b7af0aa34ee3e35ba4f94f4104c29b299bc0ed0d Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Fri, 12 Feb 2010 18:06:34 +0000 Subject: [PATCH] [undi] Ensure only one UNDI instance is loaded Loading multiple UNDI instances would be useful in systems that have several network cards with vendor PXE ROMs. However, we cannot rely on UNDI ROMs working correctly with multiple instances loaded simultaneously. The gPXE UNDI driver supports the following multi-NIC configurations: 1. Chainloading undionly.kpxe on a specific NIC. 2. Loading the UNDI driver for the first probed device and ignoring all other UNDI devices in the system. This patch refuses to probe additional UNDI devices so there can never be multiple instances of UNDI loaded. Signed-off-by: Stefan Hajnoczi Signed-off-by: Marty Connor --- src/arch/i386/drivers/net/undiload.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/arch/i386/drivers/net/undiload.c b/src/arch/i386/drivers/net/undiload.c index 1d4e88d7..47a2baed 100644 --- a/src/arch/i386/drivers/net/undiload.c +++ b/src/arch/i386/drivers/net/undiload.c @@ -58,6 +58,12 @@ int undi_load ( struct undi_device *undi, struct undi_rom *undirom ) { 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; @@ -109,6 +115,9 @@ int undi_load ( struct undi_device *undi, struct undi_rom *undirom ) { gateA20_set(); 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; @@ -151,6 +160,9 @@ int undi_unload ( struct undi_device *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 );