[Minios-devel] [UNIKRAFT PATCH] plat/xen: Fix symbol displacement while linking (x86)

[Bruno Alvisio <bruno.alvisio@xxxxxxxxx>]

The current linker script might not place _libxenplat_start, shared_info or
hypercall_page at locations 0x0, 0x1000 and 0x2000 respectively as it is
expected by the layout.

Thus, a new .text.boot section was added to ensure this symbols will be placed
in the correct expected memory locations.

Signed-off-by: Bruno Alvisio <bruno.alvisio@xxxxxxxxx>
---
@Simon: Is it necessary to add .sections for the shared_info and hypercall pages
given that they come right after _libxenplat_start?
---
 plat/xen/x86/entry64.S | 1 +
 plat/xen/x86/link64.ld | 1 +
 plat/xen/x86/setup.c   | 2 +-
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/plat/xen/x86/entry64.S b/plat/xen/x86/entry64.S
index bdaa05a..314bb70 100644
--- a/plat/xen/x86/entry64.S
+++ b/plat/xen/x86/entry64.S
@@ -52,6 +52,7 @@ ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION, .asciz "xen-3.0")
 
 .globl _libxenplat_start
 
+.section .text.boot, "ax"
 _libxenplat_start:
 #else
 
diff --git a/plat/xen/x86/link64.ld b/plat/xen/x86/link64.ld
index 2842a75..dd092aa 100644
--- a/plat/xen/x86/link64.ld
+++ b/plat/xen/x86/link64.ld
@@ -32,6 +32,7 @@ SECTIONS
        . = 0x0;
        _text = .;                      /* Text and read-only data */
        .text : {
+               *(.text.boot)
                *(.text)
                *(.gnu.warning)
        } = 0x2000
diff --git a/plat/xen/x86/setup.c b/plat/xen/x86/setup.c
index cf8bad2..44e8908 100644
--- a/plat/xen/x86/setup.c
+++ b/plat/xen/x86/setup.c
@@ -156,7 +156,7 @@ static inline void _init_mem(void)
        uk_printd(DLVL_INFO, "       max_pfn: %lx\n", max_pfn);
 
        _init_mem_build_pagetable(&start_pfn, &max_pfn);
-       //_init_mem_clear_bootstrap(); /* FIXME - stack or text screwed up? */
+       _init_mem_clear_bootstrap();
        //_init_mem_set_readonly(&_text, &_erodata); /* FIXME - shared info ro? 
*/
 
        /* Fill out mrd array */
-- 
2.3.2 (Apple Git-55)


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