Re: NetBSD/ews4800mips 9.0 on NEC EWS4800/360AD

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

I wrote:

> Note there is something wrong in bootloader (/usr/mdec/boot)
> binary so it gets "Illegal exception" error just after it's loaded
> by the primary bootxx_bfs.  An old /usr/mdec/boot binary from
> NetBSD/ews4800mips 5.0 still works.

It turns out that the primary bootxx_bfs binary doesn't load the
secondary boot built by recent toolchain.

In sys/arch/ews4800mips/stand/common/bootxx.c, load_elf() just
loads the first two problem header sections:
---
int
load_elf(uint8_t *buf, uint32_t *entry)
{
	Elf32_Ehdr *e = (void *)buf;
	Elf32_Phdr *p;
[..]
	BASSERT(e->e_phentsize == sizeof(Elf32_Phdr));
	p = (void *)(buf + e->e_phoff);
#ifdef _STANDALONE
	memcpy((void *)p->p_vaddr, buf + p->p_offset, p->p_filesz);
	p++;
	memcpy((void *)p->p_vaddr, buf + p->p_offset, p->p_filesz);
#else
---

but recent gcc/binutils seem to create three sections.

5.0 /usr/mdec/boot (by readelf -a):
---
Program Headers:
  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
  REGINFO        0x014c18 0xa0a14b98 0xa0a14b98 0x00018 0x00018 R   0x4
  LOAD           0x000080 0xa0a00000 0xa0a00000 0x14e60 0x1a538 RWE 0x40
---

9.0 /usr/mdec/boot:
---
Program Headers:
  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
  ABIFLAGS       0x015088 0xa0a14fc8 0xa0a14fc8 0x00018 0x00018 R   0x8
  REGINFO        0x015070 0xa0a14fb0 0xa0a14fb0 0x00018 0x00018 R   0x4
  LOAD           0x0000c0 0xa0a00000 0xa0a00000 0x15280 0x1a978 RWE 0x40
---

It works to change bootxx.c to check all sections in the problem header
as MI libsa loadfile_elf32.c does:

---
Index: common/bootxx.c
===================================================================
RCS file: /cvsroot/src/sys/arch/ews4800mips/stand/common/bootxx.c,v
retrieving revision 1.5
diff -u -p -d -r1.5 bootxx.c
--- common/bootxx.c	4 Feb 2009 15:22:13 -0000	1.5
+++ common/bootxx.c	6 Jun 2020 18:11:54 -0000
@@ -46,6 +46,10 @@
 
 #include "common.h"
 
+#define	IS_TEXT(p)	(p.p_flags & PF_X)
+#define	IS_DATA(p)	((p.p_flags & PF_X) == 0)
+#define	IS_BSS(p)	(p.p_filesz < p.p_memsz)
+
 #define	FILHSZ	(sizeof(struct ecoff_filehdr))
 #define	SCNHSZ	(sizeof(struct ecoff_scnhdr))
 #define	N_TXTOFF(f, a)							\
@@ -186,6 +190,7 @@ load_elf(uint8_t *buf, uint32_t *entry)
 {
 	Elf32_Ehdr *e = (void *)buf;
 	Elf32_Phdr *p;
+	int i;
 
 	if (e->e_ident[EI_MAG2] != 'L' || e->e_ident[EI_MAG3] != 'F' ||
 	    e->e_ident[EI_CLASS] != ELFCLASS32 ||
@@ -197,16 +202,39 @@ load_elf(uint8_t *buf, uint32_t *entry)
 	BASSERT(e->e_phentsize == sizeof(Elf32_Phdr));
 	p = (void *)(buf + e->e_phoff);
 #ifdef _STANDALONE
-	memcpy((void *)p->p_vaddr, buf + p->p_offset, p->p_filesz);
-	p++;
-	memcpy((void *)p->p_vaddr, buf + p->p_offset, p->p_filesz);
+	for (i = 0; i < e->e_phnum; i++) {
+		if (p[i].p_type != PT_LOAD ||
+		    (p[i].p_flags & (PF_W|PF_R|PF_X)) == 0)
+			continue;
+		if (IS_TEXT(p[i]) || IS_DATA(p[i])) {
+			memcpy((void *)p[i].p_vaddr,
+			    buf + p[i].p_offset, p[i].p_filesz);
+		}
+		if (IS_BSS(p[i])) {
+			memset((void *)(p[i].p_vaddr + p[i].p_filesz), 0,
+			    p[i].p_memsz - p[i].p_filesz);
+		}
+	}
 #else
 	DPRINTF("ELF entry point 0x%08x\n", e->e_entry);
-	DPRINTF("[text] 0x%08x 0x%x %dbyte.\n", p->p_vaddr, p->p_offset,
-	    p->p_filesz);
-	p++;
-	DPRINTF("[data] 0x%08x 0x%x %dbyte.\n", p->p_vaddr, p->p_offset,
-	    p->p_filesz);
+	for (i = 0; i < e->e_phnum; i++) {
+		if (p[i].p_type != PT_LOAD ||
+		    (p[i].p_flags & (PF_W|PF_R|PF_X)) == 0)
+			continue;
+		if (IS_TEXT(p[i])) {
+			DPRINTF("[text] 0x%08x 0x%x %dbyte.\n",
+			    p[i].p_vaddr, p[i].p_offset, p[i].p_filesz);
+		}
+		if (IS_DATA(p[i])) {
+			DPRINTF("[data] 0x%08x 0x%x %dbyte.\n",
+			    p[i].p_vaddr, p[i].p_offset, p[i].p_filesz);
+		}
+		if (IS_BSS(p[i])) {
+			DPRINTF("[bss] 0x%08x %dbyte.\n",
+			    p[i].p_vaddr + p[i].p_filesz,
+			    p[i].p_memsz - p[i].p_filesz);
+		}
+	}
 #endif
 	*entry = e->e_entry;
 
---

I'll commit fix and send a pullup request to netbsd-9.

---
Izumi Tsutsui