[PATCH 3/3] x86/boot: Use boot_vid_info and trampoline_phys variables directly from C code

[Frediano Ziglio <frediano.ziglio@xxxxxxxxx>]

No more need to pass from assembly code.

Signed-off-by: Frediano Ziglio <frediano.ziglio@xxxxxxxxx>
---
 xen/arch/x86/boot/build32.lds.S |  1 +
 xen/arch/x86/boot/head.S        | 14 +-------------
 xen/arch/x86/boot/reloc.c       | 19 ++++++++++---------
 3 files changed, 12 insertions(+), 22 deletions(-)

diff --git a/xen/arch/x86/boot/build32.lds.S b/xen/arch/x86/boot/build32.lds.S
index 2d10a75fb1..6598a24e04 100644
--- a/xen/arch/x86/boot/build32.lds.S
+++ b/xen/arch/x86/boot/build32.lds.S
@@ -48,6 +48,7 @@ SECTIONS
         DECLARE_IMPORT(__trampoline_seg_start);
         DECLARE_IMPORT(__trampoline_seg_stop);
         DECLARE_IMPORT(trampoline_phys);
+        DECLARE_IMPORT(boot_vid_info);
         . = . + GAP;
         *(.text)
         *(.text.*)
diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S
index ade2c5c43d..dcda91cfda 100644
--- a/xen/arch/x86/boot/head.S
+++ b/xen/arch/x86/boot/head.S
@@ -510,22 +510,10 @@ trampoline_setup:
         mov     %esi, sym_esi(xen_phys_start)
         mov     %esi, sym_esi(trampoline_xen_phys_start)
 
-        /* Get bottom-most low-memory stack address. */
-        mov     sym_esi(trampoline_phys), %ecx
-        add     $TRAMPOLINE_SPACE,%ecx
-
-#ifdef CONFIG_VIDEO
-        lea     sym_esi(boot_vid_info), %edx
-#else
-        xor     %edx, %edx
-#endif
-
         /* Save Multiboot / PVH info struct (after relocation) for later use. 
*/
-        push    %edx                /* Boot video info to be filled from MB2. 
*/
         mov     %ebx, %edx          /* Multiboot / PVH information address. */
-        /*      reloc(magic/eax, info/edx, trampoline/ecx, video/stk) using 
fastcall. */
+        /*      reloc(magic/eax, info/edx) using fastcall. */
         call    reloc
-        add     $4, %esp
 
 #ifdef CONFIG_PVH_GUEST
         cmpb    $0, sym_esi(pvh_boot)
diff --git a/xen/arch/x86/boot/reloc.c b/xen/arch/x86/boot/reloc.c
index 94b078d7b1..8527fa8d01 100644
--- a/xen/arch/x86/boot/reloc.c
+++ b/xen/arch/x86/boot/reloc.c
@@ -19,6 +19,9 @@
 #include <xen/kconfig.h>
 #include <xen/multiboot.h>
 #include <xen/multiboot2.h>
+#include <xen/page-size.h>
+
+#include <asm/trampoline.h>
 
 #include <public/arch-x86/hvm/start_info.h>
 
@@ -176,7 +179,7 @@ static multiboot_info_t *mbi_reloc(uint32_t mbi_in, memctx 
*ctx)
     return mbi_out;
 }
 
-static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, uint32_t video_out, 
memctx *ctx)
+static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, memctx *ctx)
 {
     const multiboot2_fixed_t *mbi_fix = _p(mbi_in);
     const multiboot2_memory_map_t *mmap_src;
@@ -185,7 +188,7 @@ static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, 
uint32_t video_out, memctx
     memory_map_t *mmap_dst;
     multiboot_info_t *mbi_out;
 #ifdef CONFIG_VIDEO
-    struct boot_video_info *video = NULL;
+    struct boot_video_info *video = &boot_vid_info;
 #endif
     uint32_t ptr;
     unsigned int i, mod_idx = 0;
@@ -290,12 +293,11 @@ static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, 
uint32_t video_out, memctx
 
 #ifdef CONFIG_VIDEO
         case MULTIBOOT2_TAG_TYPE_VBE:
-            if ( video_out )
+            if ( video )
             {
                 const struct vesa_ctrl_info *ci;
                 const struct vesa_mode_info *mi;
 
-                video = _p(video_out);
                 ci = (const void *)get_mb2_data(tag, vbe, vbe_control_info);
                 mi = (const void *)get_mb2_data(tag, vbe, vbe_mode_info);
 
@@ -321,7 +323,6 @@ static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, 
uint32_t video_out, memctx
             if ( (get_mb2_data(tag, framebuffer, framebuffer_type) !=
                   MULTIBOOT2_FRAMEBUFFER_TYPE_RGB) )
             {
-                video_out = 0;
                 video = NULL;
             }
             break;
@@ -346,10 +347,10 @@ static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, 
uint32_t video_out, memctx
 }
 
 /* SAF-1-safe */
-void *reloc(uint32_t magic, uint32_t in, uint32_t trampoline,
-            uint32_t video_info)
+void *reloc(uint32_t magic, uint32_t in)
 {
-    memctx ctx = { trampoline };
+    /* Get bottom-most low-memory stack address. */
+    memctx ctx = { (uint32_t)((long)trampoline_phys + TRAMPOLINE_SPACE) };
 
     switch ( magic )
     {
@@ -357,7 +358,7 @@ void *reloc(uint32_t magic, uint32_t in, uint32_t 
trampoline,
         return mbi_reloc(in, &ctx);
 
     case MULTIBOOT2_BOOTLOADER_MAGIC:
-        return mbi2_reloc(in, video_info, &ctx);
+        return mbi2_reloc(in, &ctx);
 
     case XEN_HVM_START_MAGIC_VALUE:
         if ( IS_ENABLED(CONFIG_PVH_GUEST) )
-- 
2.34.1