[SeaBIOS] [PATCH 3/5] paravirt: Split QEMU FW configuration initialisation

[Rob Bradford]

Split detection of QEMU FW CFG into two phases: detection and parsing of
complex structures. The qemu_cfg_preinit() function does not require
malloc() to be available.

Signed-off-by: Rob Bradford <robert.bradford at intel.com>
---
 src/fw/paravirt.c | 11 +++++++++--
 src/fw/paravirt.h |  1 +
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/fw/paravirt.c b/src/fw/paravirt.c
index 597bd1c..7044378 100644
--- a/src/fw/paravirt.c
+++ b/src/fw/paravirt.c
@@ -124,6 +124,8 @@ qemu_preinit(void)
         kvm_detect();
     }
 
+    qemu_cfg_preinit();
+
     // On emulators, get memory size from nvram.
     u32 rs = ((rtc_read(CMOS_MEM_EXTMEM2_LOW) << 16)
               | (rtc_read(CMOS_MEM_EXTMEM2_HIGH) << 24));
@@ -571,8 +573,7 @@ struct QemuCfgFile {
     char name[56];
 };
 
-void qemu_cfg_init(void)
-{
+void qemu_cfg_preinit(void) {
     if (!runningOnQEMU())
         return;
 
@@ -595,6 +596,12 @@ void qemu_cfg_init(void)
         dprintf(1, "QEMU fw_cfg DMA interface supported\n");
         cfg_dma_enabled = 1;
     }
+}
+
+void qemu_cfg_init(void)
+{
+    if (!qemu_cfg_enabled())
+        return;
 
     // Populate romfiles for legacy fw_cfg entries
     qemu_cfg_legacy();
diff --git a/src/fw/paravirt.h b/src/fw/paravirt.h
index a14d83e..2c4792a 100644
--- a/src/fw/paravirt.h
+++ b/src/fw/paravirt.h
@@ -54,6 +54,7 @@ int qemu_cfg_dma_enabled(void);
 void qemu_preinit(void);
 void qemu_platform_setup(void);
 void qemu_cfg_init(void);
+void qemu_cfg_preinit(void);
 
 u16 qemu_get_present_cpus_count(void);
 int qemu_cfg_write_file(void *src, struct romfile_s *file, u32 offset, u32 len);
-- 
2.19.2