csm: Call pci_probe_devices() late until PrepareToBoot is invoked by UEFI - SeaBIOS

26 Nov 2019

From 7dd0e8b98c71254148180b3cc432de1c4936526c Mon Sep 17 00:00:00 2001
From: gaobin gaobin@amazon.com
Date: Thu, 19 Sep 2019 11:17:46 -0700
Subject: [PATCH 1/4] csm: Call pci_probe_devices() late until PrepareToBoot is
 invoked by UEFI
On real hardware, some PCI devices are not detectable when UEFI
BIOS invokes our InitializeYourself() function. But they are
guaranteed to be available before UEFI invokes our PreparToBoot()
function.
Signed-off-by: gaobin gaobin@amazon.com
---
 src/fw/csm.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/fw/csm.c b/src/fw/csm.c
index 8359bcb..c8111cd 100644
--- a/src/fw/csm.c
+++ b/src/fw/csm.c
@@ -63,7 +63,6 @@ static void
 csm_maininit(struct bregs *regs)
 {
     interface_init();
-    pci_probe_devices();
csm_compat_table.PnPInstallationCheckSegment = SEG_BIOS;
     csm_compat_table.PnPInstallationCheckOffset = get_pnp_offset();
@@ -143,6 +142,12 @@ handle_csm_0002(struct bregs *regs)
         return;
     }
+    // On real hardware, some PCI devices are not detectable when
+    // UEFI invokes our InitializeYourself() function. But they
+    // are guaranteed to be available before UEFI invokes our
+    // PreparToBoot() function.
+    pci_probe_devices();
+
     dprintf(3, "PrepareToBoot table %04x:%04x\n", regs->es, regs->bx);
struct e820entry *p = (void *)csm_compat_table.E820Pointer;
-- 
2.17.1

    