Remove the restriction that the kernel needs to be loaded at the bottom of

physical memory.  This makes it possible to boot OpenBSD on platforms that
have physical memory start at address 0x00000000 as the EFI bootloader will
only attempt to load kernels at address 0x10000000 and above to work around
a bug in the u-boot EFI API layer.

ok patrick@

2 files changed, 17 insertions, 9 deletions

diff --git a/sys/arch/armv7/armv7/armv7_machdep.c b/sys/arch/armv7/armv7/armv7_machdep.c
index c40d6617668..5f9da10338f 100644
--- a/sys/arch/armv7/armv7/armv7_machdep.c
+++ b/sys/arch/armv7/armv7/armv7_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: armv7_machdep.c,v 1.31 2016/06/14 10:03:51 kettenis Exp $ */
+/*	$OpenBSD: armv7_machdep.c,v 1.32 2016/07/26 18:09:07 kettenis Exp $ */
 /*	$NetBSD: lubbock_machdep.c,v 1.2 2003/07/15 00:25:06 lukem Exp $ */
 
 /*
@@ -385,10 +385,11 @@ copy_io_area_map(pd_entry_t *new_pd)
 u_int
 initarm(void *arg0, void *arg1, void *arg2)
 {
-	int loop, loop1, i, physsegs;
+	int loop, loop1, i, physsegs = VM_PHYSSEG_MAX;
 	u_int l1pagetable;
 	pv_addr_t kernel_l1pt;
 	pv_addr_t fdt;
+	paddr_t loadaddr;
 	paddr_t memstart;
 	psize_t memsize;
 	void *config;
@@ -399,6 +400,7 @@ initarm(void *arg0, void *arg1, void *arg2)
 	int	(*map_func_save)(void *, bus_addr_t, bus_size_t, int,
 	    bus_space_handle_t *);
 
+	loadaddr = (paddr_t)arg0;
 	board_id = (uint32_t)arg1;
 	/*
 	 * u-boot has decided the top four bits are
@@ -514,7 +516,7 @@ initarm(void *arg0, void *arg1, void *arg2)
 	boothowto |= RB_DFLTROOT;
 #endif /* RAMDISK_HOOKS */
 
-	physical_freestart = (((unsigned long)esym - KERNEL_TEXT_BASE +0xfff) & ~0xfff) + memstart;
+	physical_freestart = (((unsigned long)esym - KERNEL_TEXT_BASE +0xfff) & ~0xfff) + loadaddr;
 	physical_freeend = MIN((uint64_t)memstart+memsize, (paddr_t)-PAGE_SIZE);
 
 	physmem = (physical_end - physical_start) / PAGE_SIZE;
@@ -557,7 +559,7 @@ initarm(void *arg0, void *arg1, void *arg2)
 	/* Define a macro to simplify memory allocation */
 #define	valloc_pages(var, np)				\
 	alloc_pages((var).pv_pa, (np));			\
-	(var).pv_va = KERNEL_BASE + (var).pv_pa - physical_start;
+	(var).pv_va = KERNEL_BASE + (var).pv_pa - loadaddr;
 
 #define alloc_pages(var, np)				\
 	(var) = physical_freestart;			\
@@ -677,10 +679,10 @@ initarm(void *arg0, void *arg1, void *arg2)
 		logical = 0x00000000;	/* offset of kernel in RAM */
 
 		logical += pmap_map_chunk(l1pagetable, KERNEL_BASE + logical,
-		    physical_start + logical, textsize,
+		    loadaddr + logical, textsize,
 		    PROT_READ | PROT_WRITE | PROT_EXEC, PTE_CACHE);
 		logical += pmap_map_chunk(l1pagetable, KERNEL_BASE + logical,
-		    physical_start + logical, totalsize - textsize,
+		    loadaddr + logical, totalsize - textsize,
 		    PROT_READ | PROT_WRITE, PTE_CACHE);
 	}
 
@@ -797,7 +799,13 @@ initarm(void *arg0, void *arg1, void *arg2)
 	uvm_page_physload(atop(physical_freestart), atop(physical_freeend),
 	    atop(physical_freestart), atop(physical_freeend), 0);
 
-	physsegs = MIN(bootconfig.dramblocks, VM_PHYSSEG_MAX);
+	if (physical_start < loadaddr) {
+		uvm_page_physload(atop(physical_start), atop(loadaddr),
+		    atop(physical_start), atop(loadaddr), 0);
+		physsegs--;
+	}
+
+	physsegs = MIN(bootconfig.dramblocks, physsegs);
 
 	for (i = 1; i < physsegs; i++) {
 		paddr_t dramstart = bootconfig.dram[i].address;
diff --git a/sys/arch/armv7/armv7/armv7_start.S b/sys/arch/armv7/armv7/armv7_start.S
index f78598eb2ce..e7d773b2bc0 100644
--- a/sys/arch/armv7/armv7/armv7_start.S
+++ b/sys/arch/armv7/armv7/armv7_start.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: armv7_start.S,v 1.6 2016/04/25 04:46:57 jsg Exp $	*/
+/*	$OpenBSD: armv7_start.S,v 1.7 2016/07/26 18:09:07 kettenis Exp $	*/
 /*	$NetBSD: lubbock_start.S,v 1.1 2003/06/18 10:51:15 bsh Exp $ */
 
 /*
@@ -161,7 +161,7 @@ _C_LABEL(bootstrap_start):
 	CPWAIT(r0)
 
 	/* Restore U-Boot arguments */
-	mov	r0, r6
+	mov	r0, r9
 	mov	r1, r7
 	mov	r2, r8