sparc: fix bootloader executable format

- The entry point has to be at the start of the text section
- Use the correct formqt ("impure") for the a.out file
- Strip all symbols (the bootloader isn't relocatable)

Change-Id: I2b973c39eaf1416f874bf1b2668b1e3090eb5f7b
Reviewed-on: https://review.haiku-os.org/c/1468
Reviewed-by: waddlesplash <[email protected]>

src/system/boot/Jamfile

@@ -38,7 +38,7 @@ rule BuildAoutLoader {
 
 actions BuildAoutLoader {
 	rm -f $(1)
-	$(TARGET_OBJCOPY_$(TARGET_PACKAGING_ARCH)) -O $(AOUT_FORMAT) $(2) $(1)
+	$(TARGET_OBJCOPY_$(TARGET_PACKAGING_ARCH)) -O $(AOUT_FORMAT) --impure -S $(2) $(1)
 }
 
 

src/system/boot/platform/openfirmware/start.cpp

@@ -27,9 +27,11 @@ extern "C" void _start(uint32 _unused1, uint32 _unused2,
 	void *openFirmwareEntry);
 extern "C" void start(void *openFirmwareEntry);
 
+#ifdef __powerpc__
 // XCOFF "entry-point" is actually a pointer to the real code
 extern "C" void *_coff_start;
 void *_coff_start = (void *)&_start;
+#endif
 
 // GCC defined globals
 extern void (*__ctor_list)(void);
@@ -52,11 +54,13 @@ call_ctors(void)
 }
 
 
+#ifdef __powerpc__
 static void
 clear_bss(void)
 {
 	memset(&__bss_start, 0, &_end - &__bss_start);
 }
+#endif
 
 
 static void
@@ -134,13 +138,15 @@ platform_boot_options(void)
 }
 
 
-extern "C" void
+extern "C" void __attribute__((section(".text.start")))
 _start(uint32 _unused1, uint32 _unused3, void *openFirmwareEntry)
 {
 	// According to the PowerPC bindings, OpenFirmware should have created
 	// a stack of 32kB or higher for us at this point
 
+#ifndef __sparc__
 	clear_bss();
+#endif
 	call_ctors();
 		// call C++ constructors before doing anything else
 

src/system/ldscripts/sparc/boot_loader_openfirmware.ld

@@ -5,12 +5,13 @@ ENTRY(_start)
 
 SECTIONS
 {
-	. = 0x202000 + SIZEOF_HEADERS;
+	. = 0x202000;
 
 	__text_begin = .;
 
 	/* text/read-only data */
-	.text :	{ *(.text .text.* .gnu.linkonce.t.*)
+	.text :	{ *(.text.start) /* Make sure entry point is at start of file */
+			  *(.text .text.* .gnu.linkonce.t.*)
 	          *(.rodata .rodata.* .gnu.linkonce.r.*)
 	          *(.sdata2) }