Module Name: src
Committed By: jakllsch
Date: Thu Aug 16 23:40:19 UTC 2012
Modified Files:
src/sys/arch/evbarm/rpi: rpi_machdep.c rpi_start.S
Log Message:
Get accessible memory quantity and kernel command line via Linux ARM 'A'-tag
interface used by Raspberry Pi's start.elf.
To generate a diff of this commit:
cvs rdiff -u -r1.4 -r1.5 src/sys/arch/evbarm/rpi/rpi_machdep.c
cvs rdiff -u -r1.3 -r1.4 src/sys/arch/evbarm/rpi/rpi_start.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/evbarm/rpi/rpi_machdep.c
diff -u src/sys/arch/evbarm/rpi/rpi_machdep.c:1.4 src/sys/arch/evbarm/rpi/rpi_machdep.c:1.5
--- src/sys/arch/evbarm/rpi/rpi_machdep.c:1.4 Thu Aug 16 18:22:46 2012
+++ src/sys/arch/evbarm/rpi/rpi_machdep.c Thu Aug 16 23:40:19 2012
@@ -1,4 +1,4 @@
-/* $NetBSD: rpi_machdep.c,v 1.4 2012/08/16 18:22:46 matt Exp $ */
+/* $NetBSD: rpi_machdep.c,v 1.5 2012/08/16 23:40:19 jakllsch Exp $ */
/*
* Copyright (c) 2002, 2003, 2005 Genetec Corporation. All rights reserved.
@@ -122,7 +122,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rpi_machdep.c,v 1.4 2012/08/16 18:22:46 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rpi_machdep.c,v 1.5 2012/08/16 23:40:19 jakllsch Exp $");
#include "opt_evbarm_boardtype.h"
#include "opt_broadcom.h"
@@ -227,6 +227,9 @@ int plcomcnmode = PLCONMODE;
#include <sys/kgdb.h>
#endif
+/* Smallest amount of RAM start.elf could give us. */
+#define RPI_MINIMUM_ARM_RAM_SPLIT (128U * 1024 * 1024)
+
void
cpu_reboot(int howto, char *bootstr)
{
@@ -324,6 +327,65 @@ static const struct pmap_devmap rpi_devm
#undef _A
#undef _S
+#define LINUX_ARM_MACHTYPE_BCM2708 3138
+
+#define LINUX_ATAG_NONE 0x00000000
+struct linux_atag_header {
+ uint32_t size;
+ uint32_t tag;
+} __packed __aligned(4);
+
+#define LINUX_ATAG_MEM 0x54410002
+struct linux_atag_mem {
+ uint32_t size;
+ uint32_t start;
+} __packed __aligned(4);
+
+#define LINUX_ATAG_CMDLINE 0x54410009
+struct linux_atag_cmdline {
+ char cmdline[1];
+} __packed __aligned(4);
+
+struct linux_atag {
+ struct linux_atag_header hdr;
+ union {
+ struct linux_atag_mem mem;
+ struct linux_atag_cmdline cmdline;
+ } u;
+} __packed __aligned(4);
+
+static void
+parse_linux_atags(void *atag_base)
+{
+ struct linux_atag *atp;
+
+ for (atp = atag_base;
+ atp->hdr.size >= sizeof(struct linux_atag_header)/sizeof(uint32_t);
+ atp = (void *)((uintptr_t)atp + sizeof(uint32_t) * atp->hdr.size)) {
+ printf("atag: size %08x tag %08x\n", atp->hdr.size, atp->hdr.tag);
+ if (atp->hdr.tag == LINUX_ATAG_MEM) {
+ if (bootconfig.dramblocks > 1) {
+ printf("Ignoring RAM block 0x%08x-0x%08x\n",
+ atp->u.mem.start, atp->u.mem.start +
+ atp->u.mem.size - 1);
+ continue;
+ }
+ physical_end = atp->u.mem.size;
+ physmem = physical_end / PAGE_SIZE;
+ KASSERT(atp->u.mem.start == 0);
+ physical_start = atp->u.mem.start;
+ bootconfig.dram[bootconfig.dramblocks].address = 0x0;
+ bootconfig.dram[bootconfig.dramblocks].pages = physmem;
+ ++bootconfig.dramblocks;
+ }
+
+ if (atp->hdr.tag == LINUX_ATAG_CMDLINE) {
+ strncpy(bootargs, atp->u.cmdline.cmdline,
+ sizeof(bootargs));
+ }
+ }
+}
+
/*
* u_int initarm(...)
*
@@ -364,13 +426,19 @@ initarm(void *arg)
printf("initarm: Configuring system ...\n");
#endif
- bootconfig.dramblocks = 1;
- physical_end = (MEMSIZE * 1024 * 1024); /* MEMSIZE */
- physmem = physical_end / PAGE_SIZE;
- physical_start = 0;
+ extern const uint32_t rpi_boot_regs[4];
+ if (rpi_boot_regs[0] == 0 &&
+ rpi_boot_regs[1] == LINUX_ARM_MACHTYPE_BCM2708) {
+ parse_linux_atags((void *)KERN_PHYSTOV(rpi_boot_regs[2]));
+ } else {
+ bootconfig.dramblocks = 1;
+ physical_end = RPI_MINIMUM_ARM_RAM_SPLIT;
+ physmem = physical_end / PAGE_SIZE;
+ physical_start = 0;
- bootconfig.dram[0].address = 0x0;
- bootconfig.dram[0].pages = physmem;
+ bootconfig.dram[0].address = 0x0;
+ bootconfig.dram[0].pages = physmem;
+ }
/*
* Our kernel is at the beginning of memory, so set our free space to
@@ -500,6 +568,9 @@ initarm(void *arg)
md_root_setconf(memory_disk, sizeof memory_disk);
#endif
+ boot_args = bootargs;
+ parse_mi_bootargs(boot_args);
+
#ifdef BOOTHOWTO
boothowto |= BOOTHOWTO;
#endif
Index: src/sys/arch/evbarm/rpi/rpi_start.S
diff -u src/sys/arch/evbarm/rpi/rpi_start.S:1.3 src/sys/arch/evbarm/rpi/rpi_start.S:1.4
--- src/sys/arch/evbarm/rpi/rpi_start.S:1.3 Thu Aug 16 21:46:18 2012
+++ src/sys/arch/evbarm/rpi/rpi_start.S Thu Aug 16 23:40:19 2012
@@ -1,4 +1,4 @@
-/* $NetBSD: rpi_start.S,v 1.3 2012/08/16 21:46:18 jakllsch Exp $ */
+/* $NetBSD: rpi_start.S,v 1.4 2012/08/16 23:40:19 jakllsch Exp $ */
/*
* Copyright (c) 2002, 2003 Genetec Corporation. All rights reserved.
@@ -88,7 +88,7 @@
#include <arm/armreg.h>
#include "assym.h"
-RCSID("$NetBSD: rpi_start.S,v 1.3 2012/08/16 21:46:18 jakllsch Exp $")
+RCSID("$NetBSD: rpi_start.S,v 1.4 2012/08/16 23:40:19 jakllsch Exp $")
/* Location (in MiB) to put temporary MMU tables just below. */
/* Raspberry Pi start.elf will give us anywhere between 128MiB and 240MiB */
@@ -126,6 +126,9 @@ RCSID("$NetBSD: rpi_start.S,v 1.3 2012/0
.global _C_LABEL(rpi_start)
_C_LABEL(rpi_start):
+ adr r8, rpi_boot_regs
+ stmia r8!, {r0-r3}
+
mrs r0, cpsr
bic r0, r0, #PSR_MODE
orr r0, r0, #(I32_bit | F32_bit | PSR_SVC32_MODE)
@@ -323,3 +326,7 @@ mmu_init_table:
/* end of table */
MMU_INIT(0, 0, 0, 0)
+
+ .globl _C_LABEL(rpi_boot_regs)
+rpi_boot_regs:
+ .space 4 * 4
