[src/trunk]: src/sys/arch/evbarm/rpi Get accessible memory quantity and kerne...

[jakllsch <jakllsch%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/b7ac3eda0835
branches:  trunk
changeset: 781073:b7ac3eda0835
user:      jakllsch <jakllsch%NetBSD.org@localhost>
date:      Thu Aug 16 23:40:19 2012 +0000

description:
Get accessible memory quantity and kernel command line via Linux ARM 'A'-tag
interface used by Raspberry Pi's start.elf.

diffstat:

 sys/arch/evbarm/rpi/rpi_machdep.c |  87 +++++++++++++++++++++++++++++++++++---
 sys/arch/evbarm/rpi/rpi_start.S   |  11 ++++-
 2 files changed, 88 insertions(+), 10 deletions(-)

diffs (166 lines):

diff -r 5ebb1e799e59 -r b7ac3eda0835 sys/arch/evbarm/rpi/rpi_machdep.c
--- a/sys/arch/evbarm/rpi/rpi_machdep.c Thu Aug 16 23:22:44 2012 +0000
+++ b/sys/arch/evbarm/rpi/rpi_machdep.c Thu Aug 16 23:40:19 2012 +0000
@@ -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 @@
 #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 @@
 #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 @@
        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 @@
        md_root_setconf(memory_disk, sizeof memory_disk);
 #endif
 
+       boot_args = bootargs;
+       parse_mi_bootargs(boot_args);
+
 #ifdef BOOTHOWTO
        boothowto |= BOOTHOWTO;
 #endif
diff -r 5ebb1e799e59 -r b7ac3eda0835 sys/arch/evbarm/rpi/rpi_start.S
--- a/sys/arch/evbarm/rpi/rpi_start.S   Thu Aug 16 23:22:44 2012 +0000
+++ b/sys/arch/evbarm/rpi/rpi_start.S   Thu Aug 16 23:40:19 2012 +0000
@@ -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 @@
 
        .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 @@
 
        /* end of table */
        MMU_INIT(0, 0, 0, 0)
+
+       .globl  _C_LABEL(rpi_boot_regs)
+rpi_boot_regs:
+       .space 4 * 4