[PATCH v4 04/11] libgloss: mips: Boot and startup code improvements inc. linker script fixes

Jovan Dmitrovic <[email protected]> Wed, 11 Jun 2025 14:18:49 +0000
Newsgroups	gmane.comp.lib.newlib
Message-ID	<[email protected]>
From: Robert Suchanek <[email protected]>

Add .eh_frame_hdr and .gnu_extab to linker scripts for compactEH
Fix orphaned .gcc_except_table sections in uhi32.ld.
Fix orphaned .gcc_except_table sections in mti32.ld.

Signed-off-by: Jovan Dmitrović <[email protected]>
---
 libgloss/mips/boot/reset.S        |  7 ++++++
 libgloss/mips/boot/reset_predef.S | 18 ++++++++++++--
 libgloss/mips/hal/minicrt.S       | 24 ++++++++++++------
 libgloss/mips/mti32.ld            | 19 ++++++++++++--
 libgloss/mips/uhi32.ld            | 41 ++++++++++++++++++++++---------
 libgloss/mips/uhi64_64.ld         | 41 ++++++++++++++++++++++---------
 libgloss/mips/uhi64_n32.ld        | 41 ++++++++++++++++++++++---------
 7 files changed, 144 insertions(+), 47 deletions(-)

diff --git a/libgloss/mips/boot/reset.S b/libgloss/mips/boot/reset.S
index 163933b0b..3abae9528 100644
--- a/libgloss/mips/boot/reset.S
+++ b/libgloss/mips/boot/reset.S
@@ -148,6 +148,13 @@ $Lcopy_to_ram_done:
 	eret
 
 $Lall_done:
+	/* Allow an exit hook to intercept the end of execution */
+	.weak __boot_exit_hook
+	lui	a2, %hi(__boot_exit_hook)
+	addiu	a2, a2, %lo(__boot_exit_hook)
+	beqz	a2, 1f
+	jalr	a2
+1:
 	/*
 	 * If _start returns it will return to this point.
 	 * Just spin here reporting the exit.
diff --git a/libgloss/mips/boot/reset_predef.S b/libgloss/mips/boot/reset_predef.S
index 592b592b9..b50d9e4f3 100644
--- a/libgloss/mips/boot/reset_predef.S
+++ b/libgloss/mips/boot/reset_predef.S
@@ -73,6 +73,8 @@ $Lnot_nmi:
 	/* Init CP0 Status, Count, Compare, Watch*, and Cause */
 	jal	__init_cp0
 
+#if !defined(HCI)
+
 #if (defined(SLINE_ENC) && SLINE_ENC != 0) || (defined(MEM_MAPPED_L2C) && MEM_MAPPED_L2C != 0)
 	/*
 	 * Initialise L2/L3 cache
@@ -81,10 +83,12 @@ $Lnot_nmi:
 	jal	 __init_l23cache
 #endif
 
-
 #if defined(ILINE_ENC) && ILINE_ENC != 0
 	/* Initialize the L1 instruction cache */
 	jal	  __init_icache
+#endif
+
+#endif /* !defined(HCI) */
 
 	/*
 	 * The changing of Kernel mode cacheability must be done from KSEG1
@@ -97,7 +101,8 @@ $Lnot_nmi:
 	li	a1, 0xf
 	ins	a2, a1, 29, 1		/* changed to KSEG1 address by setting bit 29 */
 	jalr	a2
-#endif
+
+#if !defined(HCI)
 
 #if (defined(SLINE_ENC) && SLINE_ENC != 0) || (defined(MEM_MAPPED_L2C) && MEM_MAPPED_L2C != 0)
 	/* Support initialising L2 with L1 cache enabled */
@@ -109,6 +114,8 @@ $Lnot_nmi:
 	jal	__init_dcache
 #endif
 
+#endif /* !defined(HCI) */
+
 #if defined(HAVE_TLB) && HAVE_TLB
 	/* Initialize the TLB */
 	jal	__init_tlb
@@ -168,6 +175,13 @@ $Lcopy_to_ram_done:
 	eret
 
 $Lall_done:
+	/* Allow an exit hook to intercept the end of execution */
+	.weak __boot_exit_hook
+	lui	a2, %hi(__boot_exit_hook)
+	addiu	a2, a2, %lo(__boot_exit_hook)
+	beqz	a2, 1f
+	jalr	a2
+1:
 	/*
 	 * If _start returns it will return to this point.
 	 * Just spin here reporting the exit.
diff --git a/libgloss/mips/hal/minicrt.S b/libgloss/mips/hal/minicrt.S
index fa4759499..bcf6caf77 100644
--- a/libgloss/mips/hal/minicrt.S
+++ b/libgloss/mips/hal/minicrt.S
@@ -1,7 +1,13 @@
 #include <mips/asm.h>
+#include <mips/m32c0.h>
 #include <mips/regdef.h>
 
 LEAF(_start)
+#ifdef __mips_dsp
+	mfc0    t0, C0_STATUS
+	or      t0, t0, SR_MX
+	mtc0    t0, C0_STATUS
+#endif
 	/* Preserve return address */
 	move s0, ra
 	/* Set up global pointer for small data access */
@@ -9,13 +15,13 @@ LEAF(_start)
 	/* Set up stack pointer */
 	LA sp, __stack
 	/* Zero the BSS */
-	LA v0, _fbss
-	LA v1, _end
-	beq v0,v1,2f
+	LA t0, _fbss
+	LA t1, _end
+	beq t0,t1,2f
 1:
-	addiu v0,v0,4
-	sw zero,-4(v0)
-	bne v0,v1,1b
+	addiu t0,t0,4
+	sw zero,-4(t0)
+	bne t0,t1,1b
 2:
 	/* Set arguments to be null for main */
 	li a0, 0
@@ -24,8 +30,12 @@ LEAF(_start)
 	addiu sp, sp, -(NARGSAVE * SZARG)
 	/* Jump to C code */
 	jal main
-
+	/* Call the exit handler */
+	move a0, va0
+	jal __exit
 	/* Return to boot */
 	move ra, s0
+	.weak __exit
+AENT(__exit)
 	jr ra
 END(_start)
diff --git a/libgloss/mips/mti32.ld b/libgloss/mips/mti32.ld
index 9e2b18fb5..f54fdac7f 100644
--- a/libgloss/mips/mti32.ld
+++ b/libgloss/mips/mti32.ld
@@ -55,15 +55,30 @@ SECTIONS
   PROVIDE (etext  =  .);
   _etext  =  .;
 
-  .eh_frame_hdr : { *(.eh_frame_hdr) }
+  .eh_frame_hdr : { *(.eh_frame_hdr) *(.eh_frame_entry .eh_frame_entry.*) }
   .eh_frame : {
     /* The .eh_frame section from the crtend file contains the
        end of eh_frame marker and it must be last.  */
     KEEP (*(EXCLUDE_FILE (*crtend.o) .eh_frame))
     KEEP (*(.eh_frame))
   }
-  .gcc_except_table : { *(.gcc_except_table) }
+  .gcc_except_table : { *(.gcc_except_table .gcc_except_table.*) }
+  .gnu_extab   : { *(.gnu_extab .gnu_extab.*) }
   .jcr : { KEEP (*(.jcr)) }
+  .init_array     :
+  {
+    PROVIDE_HIDDEN (__init_array_start = .);
+    KEEP (*(SORT(.init_array.*)))
+    KEEP (*(.init_array))
+    PROVIDE_HIDDEN (__init_array_end = .);
+  }
+  .fini_array     :
+  {
+    PROVIDE_HIDDEN (__fini_array_start = .);
+    KEEP (*(SORT(.fini_array.*)))
+    KEEP (*(.fini_array))
+    PROVIDE_HIDDEN (__fini_array_end = .);
+  }
   .ctors    :
   {
     /* gcc uses crtbegin.o to find the start of
diff --git a/libgloss/mips/uhi32.ld b/libgloss/mips/uhi32.ld
index d9df8e5e0..96f697add 100644
--- a/libgloss/mips/uhi32.ld
+++ b/libgloss/mips/uhi32.ld
@@ -125,10 +125,12 @@ SECTIONS
     . = ALIGN(8);
   } = 0
 
-  PROVIDE (__flash_app_start = SIZEOF(.bootrom) + __flash_start);
+  PROVIDE (__flash_app_start = DEFINED(__xip)
+			       ? ALIGN(__flash_start + SIZEOF(.bootrom), 0x1000)
+			       : __flash_start + SIZEOF(.bootrom));
 
   __aligned_app_start = DEFINED(__xip)
-			? __bev_override + SIZEOF(.bootrom)
+			? ALIGN(__bev_override + SIZEOF(.bootrom), 0x1000)
 			: ALIGN(__app_start, 0x1000);
 
   PROVIDE (__ebase_size = 0x200);
@@ -155,7 +157,7 @@ SECTIONS
     . = ALIGN(8);
   } = 0
 
-  .text . : AT (LOADADDR (.exception_vector) + SIZEOF(.exception_vector)) {
+  .text : {
      _ftext = . ;
     PROVIDE (eprol  =  .);
     *(.text)
@@ -164,13 +166,13 @@ SECTIONS
     *(.mips16.fn.*)
     *(.mips16.call.*)
   }
-  .init . : AT (LOADADDR (.text) + SIZEOF(.text)) {
+  .init : {
     KEEP (*(.init))
   }
-  .fini . : AT (LOADADDR (.init) + SIZEOF(.init)) {
+  .fini : {
     KEEP (*(.fini))
   }
-  .rel.sdata . : AT (LOADADDR (.fini) + SIZEOF(.fini)) {
+  .rel.sdata : {
     PROVIDE (__runtime_reloc_start = .);
     *(.rel.sdata)
     PROVIDE (__runtime_reloc_stop = .);
@@ -178,11 +180,26 @@ SECTIONS
   PROVIDE (etext  =  .);
   _etext  =  .;
 
-  .eh_frame_hdr . : AT (LOADADDR (.rel.sdata) + SIZEOF(.rel.sdata)) { *(.eh_frame_hdr) }
-  .eh_frame . : AT (LOADADDR (.eh_frame_hdr) + SIZEOF(.eh_frame_hdr)) { KEEP (*(.eh_frame)) }
-  .gcc_except_table . : AT (LOADADDR (.eh_frame) + SIZEOF(.eh_frame)) { *(.gcc_except_table) }
-  .jcr . : AT (LOADADDR (.gcc_except_table) + SIZEOF(.gcc_except_table)) { KEEP (*(.jcr)) }
-  .ctors . : AT (LOADADDR (.jcr) + SIZEOF(.jcr))
+  .eh_frame_hdr : { *(.eh_frame_hdr) *(.eh_frame_entry .eh_frame_entry.*) }
+  .eh_frame : { KEEP (*(.eh_frame)) }
+  .gcc_except_table : { *(.gcc_except_table .gcc_except_table.*) }
+  .gnu_extab : { *(.gnu_extab .gnu_extab.*) }
+  .jcr : { KEEP (*(.jcr)) }
+  .init_array :
+  {
+    PROVIDE_HIDDEN (__init_array_start = .);
+    KEEP (*(SORT(.init_array.*)))
+    KEEP (*(.init_array))
+    PROVIDE_HIDDEN (__init_array_end = .);
+  }
+  .fini_array     :
+  {
+    PROVIDE_HIDDEN (__fini_array_start = .);
+    KEEP (*(SORT(.fini_array.*)))
+    KEEP (*(.fini_array))
+    PROVIDE_HIDDEN (__fini_array_end = .);
+  }
+  .ctors    :
   {
     /* gcc uses crtbegin.o to find the start of
        the constructors, so we make sure it is
@@ -206,7 +223,7 @@ SECTIONS
     KEEP (*(.ctors))
   }
 
-  .dtors . : AT (LOADADDR (.ctors) + SIZEOF(.ctors))
+  .dtors :
   {
     KEEP (*crtbegin.o(.dtors))
     KEEP (*(EXCLUDE_FILE (*crtend.o) .dtors))
diff --git a/libgloss/mips/uhi64_64.ld b/libgloss/mips/uhi64_64.ld
index 15aeb2ecc..1aece1bf2 100644
--- a/libgloss/mips/uhi64_64.ld
+++ b/libgloss/mips/uhi64_64.ld
@@ -125,10 +125,12 @@ SECTIONS
     . = ALIGN(8);
   } = 0
 
-  PROVIDE (__flash_app_start = SIZEOF(.bootrom) + __flash_start);
+  PROVIDE (__flash_app_start = DEFINED(__xip)
+			       ? ALIGN(__flash_start + SIZEOF(.bootrom), 0x1000)
+			       : __flash_start + SIZEOF(.bootrom));
 
   __aligned_app_start = DEFINED(__xip)
-			? __bev_override + SIZEOF(.bootrom)
+			? ALIGN(__bev_override + SIZEOF(.bootrom), 0x1000)
 			: ALIGN(__app_start, 0x1000);
 
   PROVIDE (__ebase_size = 0x200);
@@ -155,7 +157,7 @@ SECTIONS
     . = ALIGN(8);
   } = 0
 
-  .text . : AT (LOADADDR (.exception_vector) + SIZEOF(.exception_vector)) {
+  .text : {
      _ftext = . ;
     PROVIDE (eprol  =  .);
     *(.text)
@@ -164,13 +166,13 @@ SECTIONS
     *(.mips16.fn.*)
     *(.mips16.call.*)
   }
-  .init . : AT (LOADADDR (.text) + SIZEOF(.text)) {
+  .init : {
     KEEP (*(.init))
   }
-  .fini . : AT (LOADADDR (.init) + SIZEOF(.init)) {
+  .fini : {
     KEEP (*(.fini))
   }
-  .rel.sdata . : AT (LOADADDR (.fini) + SIZEOF(.fini)) {
+  .rel.sdata : {
     PROVIDE (__runtime_reloc_start = .);
     *(.rel.sdata)
     PROVIDE (__runtime_reloc_stop = .);
@@ -178,11 +180,26 @@ SECTIONS
   PROVIDE (etext  =  .);
   _etext  =  .;
 
-  .eh_frame_hdr . : AT (LOADADDR (.rel.sdata) + SIZEOF(.rel.sdata)) { *(.eh_frame_hdr) }
-  .eh_frame . : AT (LOADADDR (.eh_frame_hdr) + SIZEOF(.eh_frame_hdr)) { KEEP (*(.eh_frame)) }
-  .gcc_except_table . : AT (LOADADDR (.eh_frame) + SIZEOF(.eh_frame)) { *(.gcc_except_table) }
-  .jcr . : AT (LOADADDR (.gcc_except_table) + SIZEOF(.gcc_except_table)) { KEEP (*(.jcr)) }
-  .ctors . : AT (LOADADDR (.jcr) + SIZEOF(.jcr))
+  .eh_frame_hdr : { *(.eh_frame_hdr) *(.eh_frame_entry .eh_frame_entry.*) }
+  .eh_frame : { KEEP (*(.eh_frame)) }
+  .gcc_except_table : { *(.gcc_except_table .gcc_except_table.*) }
+  .gnu_extab : { *(.gnu_extab .gnu_extab.*) }
+  .jcr : { KEEP (*(.jcr)) }
+  .init_array :
+  {
+    PROVIDE_HIDDEN (__init_array_start = .);
+    KEEP (*(SORT(.init_array.*)))
+    KEEP (*(.init_array))
+    PROVIDE_HIDDEN (__init_array_end = .);
+  }
+  .fini_array     :
+  {
+    PROVIDE_HIDDEN (__fini_array_start = .);
+    KEEP (*(SORT(.fini_array.*)))
+    KEEP (*(.fini_array))
+    PROVIDE_HIDDEN (__fini_array_end = .);
+  }
+  .ctors    :
   {
     /* gcc uses crtbegin.o to find the start of
        the constructors, so we make sure it is
@@ -206,7 +223,7 @@ SECTIONS
     KEEP (*(.ctors))
   }
 
-  .dtors . : AT (LOADADDR (.ctors) + SIZEOF(.ctors))
+  .dtors :
   {
     KEEP (*crtbegin.o(.dtors))
     KEEP (*(EXCLUDE_FILE (*crtend.o) .dtors))
diff --git a/libgloss/mips/uhi64_n32.ld b/libgloss/mips/uhi64_n32.ld
index d68f2eaaa..2ca0b4c11 100644
--- a/libgloss/mips/uhi64_n32.ld
+++ b/libgloss/mips/uhi64_n32.ld
@@ -125,10 +125,12 @@ SECTIONS
     . = ALIGN(8);
   } = 0
 
-  PROVIDE (__flash_app_start = SIZEOF(.bootrom) + __flash_start);
+  PROVIDE (__flash_app_start = DEFINED(__xip)
+			       ? ALIGN(__flash_start + SIZEOF(.bootrom), 0x1000)
+			       : __flash_start + SIZEOF(.bootrom));
 
   __aligned_app_start = DEFINED(__xip)
-			? __bev_override + SIZEOF(.bootrom)
+			? ALIGN(__bev_override + SIZEOF(.bootrom), 0x1000)
 			: ALIGN(__app_start, 0x1000);
 
   PROVIDE (__ebase_size = 0x200);
@@ -155,7 +157,7 @@ SECTIONS
     . = ALIGN(8);
   } = 0
 
-  .text . : AT (LOADADDR (.exception_vector) + SIZEOF(.exception_vector)) {
+  .text : {
      _ftext = . ;
     PROVIDE (eprol  =  .);
     *(.text)
@@ -164,13 +166,13 @@ SECTIONS
     *(.mips16.fn.*)
     *(.mips16.call.*)
   }
-  .init . : AT (LOADADDR (.text) + SIZEOF(.text)) {
+  .init : {
     KEEP (*(.init))
   }
-  .fini . : AT (LOADADDR (.init) + SIZEOF(.init)) {
+  .fini : {
     KEEP (*(.fini))
   }
-  .rel.sdata . : AT (LOADADDR (.fini) + SIZEOF(.fini)) {
+  .rel.sdata : {
     PROVIDE (__runtime_reloc_start = .);
     *(.rel.sdata)
     PROVIDE (__runtime_reloc_stop = .);
@@ -178,11 +180,26 @@ SECTIONS
   PROVIDE (etext  =  .);
   _etext  =  .;
 
-  .eh_frame_hdr . : AT (LOADADDR (.rel.sdata) + SIZEOF(.rel.sdata)) { *(.eh_frame_hdr) }
-  .eh_frame . : AT (LOADADDR (.eh_frame_hdr) + SIZEOF(.eh_frame_hdr)) { KEEP (*(.eh_frame)) }
-  .gcc_except_table . : AT (LOADADDR (.eh_frame) + SIZEOF(.eh_frame)) { *(.gcc_except_table) }
-  .jcr . : AT (LOADADDR (.gcc_except_table) + SIZEOF(.gcc_except_table)) { KEEP (*(.jcr)) }
-  .ctors . : AT (LOADADDR (.jcr) + SIZEOF(.jcr))
+  .eh_frame_hdr : { *(.eh_frame_hdr) *(.eh_frame_entry .eh_frame_entry.*) }
+  .eh_frame : { KEEP (*(.eh_frame)) }
+  .gcc_except_table : { *(.gcc_except_table .gcc_except_table.*) }
+  .gnu_extab : { *(.gnu_extab .gnu_extab.*) }
+  .jcr : { KEEP (*(.jcr)) }
+  .init_array :
+  {
+    PROVIDE_HIDDEN (__init_array_start = .);
+    KEEP (*(SORT(.init_array.*)))
+    KEEP (*(.init_array))
+    PROVIDE_HIDDEN (__init_array_end = .);
+  }
+  .fini_array     :
+  {
+    PROVIDE_HIDDEN (__fini_array_start = .);
+    KEEP (*(SORT(.fini_array.*)))
+    KEEP (*(.fini_array))
+    PROVIDE_HIDDEN (__fini_array_end = .);
+  }
+  .ctors    :
   {
     /* gcc uses crtbegin.o to find the start of
        the constructors, so we make sure it is
@@ -206,7 +223,7 @@ SECTIONS
     KEEP (*(.ctors))
   }
 
-  .dtors . : AT (LOADADDR (.ctors) + SIZEOF(.ctors))
+  .dtors :
   {
     KEEP (*crtbegin.o(.dtors))
     KEEP (*(EXCLUDE_FILE (*crtend.o) .dtors))
-- 
2.34.1