qemu/hw/misc/bcm2835_property.c
Daniel Bertalan f802ff1e28 hw/arm/bcm2835_property: Implement "get command line" message
This query copies the kernel command line into the message buffer. It
was previously stubbed out to return empty, this commit makes it reflect
the arguments specified with `-append`.

I observed the following peculiarities on my Pi 3B+:
- If the buffer is shorter than the string, the response header gives
  the full length, but no data is actually copied.
- No NUL terminator is added: even if the buffer is long enough to fit
  one, the buffer's original contents are preserved past the string's
  end.
- The VC firmware adds the following extra parameters beside the
  user-supplied ones (via /boot/cmdline.txt): `video`, `vc_mem.mem_base`
  and `vc_mem.mem_size`. This is currently not implemented in qemu.

Signed-off-by: Daniel Bertalan <dani@danielbertalan.dev>
Message-id: 20230425103250.56653-1-dani@danielbertalan.dev
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: added comment about NUL and short-buffer behaviour]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2023-05-02 15:47:40 +01:00

460 lines
15 KiB
C

/*
* Raspberry Pi emulation (c) 2012 Gregory Estrade
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "hw/misc/bcm2835_property.h"
#include "hw/qdev-properties.h"
#include "migration/vmstate.h"
#include "hw/irq.h"
#include "hw/misc/bcm2835_mbox_defs.h"
#include "sysemu/dma.h"
#include "qemu/log.h"
#include "qemu/module.h"
#include "trace.h"
/* https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface */
static void bcm2835_property_mbox_push(BCM2835PropertyState *s, uint32_t value)
{
uint32_t tag;
uint32_t bufsize;
uint32_t tot_len;
size_t resplen;
uint32_t tmp;
int n;
uint32_t offset, length, color;
/*
* Copy the current state of the framebuffer config; we will update
* this copy as we process tags and then ask the framebuffer to use
* it at the end.
*/
BCM2835FBConfig fbconfig = s->fbdev->config;
bool fbconfig_updated = false;
value &= ~0xf;
s->addr = value;
tot_len = ldl_le_phys(&s->dma_as, value);
/* @(addr + 4) : Buffer response code */
value = s->addr + 8;
while (value + 8 <= s->addr + tot_len) {
tag = ldl_le_phys(&s->dma_as, value);
bufsize = ldl_le_phys(&s->dma_as, value + 4);
/* @(value + 8) : Request/response indicator */
resplen = 0;
switch (tag) {
case 0x00000000: /* End tag */
break;
case 0x00000001: /* Get firmware revision */
stl_le_phys(&s->dma_as, value + 12, 346337);
resplen = 4;
break;
case 0x00010001: /* Get board model */
qemu_log_mask(LOG_UNIMP,
"bcm2835_property: 0x%08x get board model NYI\n",
tag);
resplen = 4;
break;
case 0x00010002: /* Get board revision */
stl_le_phys(&s->dma_as, value + 12, s->board_rev);
resplen = 4;
break;
case 0x00010003: /* Get board MAC address */
resplen = sizeof(s->macaddr.a);
dma_memory_write(&s->dma_as, value + 12, s->macaddr.a, resplen,
MEMTXATTRS_UNSPECIFIED);
break;
case 0x00010004: /* Get board serial */
qemu_log_mask(LOG_UNIMP,
"bcm2835_property: 0x%08x get board serial NYI\n",
tag);
resplen = 8;
break;
case 0x00010005: /* Get ARM memory */
/* base */
stl_le_phys(&s->dma_as, value + 12, 0);
/* size */
stl_le_phys(&s->dma_as, value + 16, s->fbdev->vcram_base);
resplen = 8;
break;
case 0x00010006: /* Get VC memory */
/* base */
stl_le_phys(&s->dma_as, value + 12, s->fbdev->vcram_base);
/* size */
stl_le_phys(&s->dma_as, value + 16, s->fbdev->vcram_size);
resplen = 8;
break;
case 0x00028001: /* Set power state */
/* Assume that whatever device they asked for exists,
* and we'll just claim we set it to the desired state
*/
tmp = ldl_le_phys(&s->dma_as, value + 16);
stl_le_phys(&s->dma_as, value + 16, (tmp & 1));
resplen = 8;
break;
/* Clocks */
case 0x00030001: /* Get clock state */
stl_le_phys(&s->dma_as, value + 16, 0x1);
resplen = 8;
break;
case 0x00038001: /* Set clock state */
qemu_log_mask(LOG_UNIMP,
"bcm2835_property: 0x%08x set clock state NYI\n",
tag);
resplen = 8;
break;
case 0x00030002: /* Get clock rate */
case 0x00030004: /* Get max clock rate */
case 0x00030007: /* Get min clock rate */
switch (ldl_le_phys(&s->dma_as, value + 12)) {
case 1: /* EMMC */
stl_le_phys(&s->dma_as, value + 16, 50000000);
break;
case 2: /* UART */
stl_le_phys(&s->dma_as, value + 16, 3000000);
break;
default:
stl_le_phys(&s->dma_as, value + 16, 700000000);
break;
}
resplen = 8;
break;
case 0x00038002: /* Set clock rate */
case 0x00038004: /* Set max clock rate */
case 0x00038007: /* Set min clock rate */
qemu_log_mask(LOG_UNIMP,
"bcm2835_property: 0x%08x set clock rate NYI\n",
tag);
resplen = 8;
break;
/* Temperature */
case 0x00030006: /* Get temperature */
stl_le_phys(&s->dma_as, value + 16, 25000);
resplen = 8;
break;
case 0x0003000A: /* Get max temperature */
stl_le_phys(&s->dma_as, value + 16, 99000);
resplen = 8;
break;
/* Frame buffer */
case 0x00040001: /* Allocate buffer */
stl_le_phys(&s->dma_as, value + 12, fbconfig.base);
stl_le_phys(&s->dma_as, value + 16,
bcm2835_fb_get_size(&fbconfig));
resplen = 8;
break;
case 0x00048001: /* Release buffer */
resplen = 0;
break;
case 0x00040002: /* Blank screen */
resplen = 4;
break;
case 0x00044003: /* Test physical display width/height */
case 0x00044004: /* Test virtual display width/height */
resplen = 8;
break;
case 0x00048003: /* Set physical display width/height */
fbconfig.xres = ldl_le_phys(&s->dma_as, value + 12);
fbconfig.yres = ldl_le_phys(&s->dma_as, value + 16);
bcm2835_fb_validate_config(&fbconfig);
fbconfig_updated = true;
/* fall through */
case 0x00040003: /* Get physical display width/height */
stl_le_phys(&s->dma_as, value + 12, fbconfig.xres);
stl_le_phys(&s->dma_as, value + 16, fbconfig.yres);
resplen = 8;
break;
case 0x00048004: /* Set virtual display width/height */
fbconfig.xres_virtual = ldl_le_phys(&s->dma_as, value + 12);
fbconfig.yres_virtual = ldl_le_phys(&s->dma_as, value + 16);
bcm2835_fb_validate_config(&fbconfig);
fbconfig_updated = true;
/* fall through */
case 0x00040004: /* Get virtual display width/height */
stl_le_phys(&s->dma_as, value + 12, fbconfig.xres_virtual);
stl_le_phys(&s->dma_as, value + 16, fbconfig.yres_virtual);
resplen = 8;
break;
case 0x00044005: /* Test depth */
resplen = 4;
break;
case 0x00048005: /* Set depth */
fbconfig.bpp = ldl_le_phys(&s->dma_as, value + 12);
bcm2835_fb_validate_config(&fbconfig);
fbconfig_updated = true;
/* fall through */
case 0x00040005: /* Get depth */
stl_le_phys(&s->dma_as, value + 12, fbconfig.bpp);
resplen = 4;
break;
case 0x00044006: /* Test pixel order */
resplen = 4;
break;
case 0x00048006: /* Set pixel order */
fbconfig.pixo = ldl_le_phys(&s->dma_as, value + 12);
bcm2835_fb_validate_config(&fbconfig);
fbconfig_updated = true;
/* fall through */
case 0x00040006: /* Get pixel order */
stl_le_phys(&s->dma_as, value + 12, fbconfig.pixo);
resplen = 4;
break;
case 0x00044007: /* Test pixel alpha */
resplen = 4;
break;
case 0x00048007: /* Set alpha */
fbconfig.alpha = ldl_le_phys(&s->dma_as, value + 12);
bcm2835_fb_validate_config(&fbconfig);
fbconfig_updated = true;
/* fall through */
case 0x00040007: /* Get alpha */
stl_le_phys(&s->dma_as, value + 12, fbconfig.alpha);
resplen = 4;
break;
case 0x00040008: /* Get pitch */
stl_le_phys(&s->dma_as, value + 12,
bcm2835_fb_get_pitch(&fbconfig));
resplen = 4;
break;
case 0x00044009: /* Test virtual offset */
resplen = 8;
break;
case 0x00048009: /* Set virtual offset */
fbconfig.xoffset = ldl_le_phys(&s->dma_as, value + 12);
fbconfig.yoffset = ldl_le_phys(&s->dma_as, value + 16);
bcm2835_fb_validate_config(&fbconfig);
fbconfig_updated = true;
/* fall through */
case 0x00040009: /* Get virtual offset */
stl_le_phys(&s->dma_as, value + 12, fbconfig.xoffset);
stl_le_phys(&s->dma_as, value + 16, fbconfig.yoffset);
resplen = 8;
break;
case 0x0004000a: /* Get/Test/Set overscan */
case 0x0004400a:
case 0x0004800a:
stl_le_phys(&s->dma_as, value + 12, 0);
stl_le_phys(&s->dma_as, value + 16, 0);
stl_le_phys(&s->dma_as, value + 20, 0);
stl_le_phys(&s->dma_as, value + 24, 0);
resplen = 16;
break;
case 0x0004800b: /* Set palette */
offset = ldl_le_phys(&s->dma_as, value + 12);
length = ldl_le_phys(&s->dma_as, value + 16);
n = 0;
while (n < length - offset) {
color = ldl_le_phys(&s->dma_as, value + 20 + (n << 2));
stl_le_phys(&s->dma_as,
s->fbdev->vcram_base + ((offset + n) << 2), color);
n++;
}
stl_le_phys(&s->dma_as, value + 12, 0);
resplen = 4;
break;
case 0x00040013: /* Get number of displays */
stl_le_phys(&s->dma_as, value + 12, 1);
resplen = 4;
break;
case 0x00060001: /* Get DMA channels */
/* channels 2-5 */
stl_le_phys(&s->dma_as, value + 12, 0x003C);
resplen = 4;
break;
case 0x00050001: /* Get command line */
/*
* We follow the firmware behaviour: no NUL terminator is
* written to the buffer, and if the buffer is too short
* we report the required length in the response header
* and copy nothing to the buffer.
*/
resplen = strlen(s->command_line);
if (bufsize >= resplen)
address_space_write(&s->dma_as, value + 12,
MEMTXATTRS_UNSPECIFIED, s->command_line,
resplen);
break;
default:
qemu_log_mask(LOG_UNIMP,
"bcm2835_property: unhandled tag 0x%08x\n", tag);
break;
}
trace_bcm2835_mbox_property(tag, bufsize, resplen);
if (tag == 0) {
break;
}
stl_le_phys(&s->dma_as, value + 8, (1 << 31) | resplen);
value += bufsize + 12;
}
/* Reconfigure framebuffer if required */
if (fbconfig_updated) {
bcm2835_fb_reconfigure(s->fbdev, &fbconfig);
}
/* Buffer response code */
stl_le_phys(&s->dma_as, s->addr + 4, (1 << 31));
}
static uint64_t bcm2835_property_read(void *opaque, hwaddr offset,
unsigned size)
{
BCM2835PropertyState *s = opaque;
uint32_t res = 0;
switch (offset) {
case MBOX_AS_DATA:
res = MBOX_CHAN_PROPERTY | s->addr;
s->pending = false;
qemu_set_irq(s->mbox_irq, 0);
break;
case MBOX_AS_PENDING:
res = s->pending;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
__func__, offset);
return 0;
}
return res;
}
static void bcm2835_property_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
{
BCM2835PropertyState *s = opaque;
switch (offset) {
case MBOX_AS_DATA:
/* bcm2835_mbox should check our pending status before pushing */
assert(!s->pending);
s->pending = true;
bcm2835_property_mbox_push(s, value);
qemu_set_irq(s->mbox_irq, 1);
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
__func__, offset);
return;
}
}
static const MemoryRegionOps bcm2835_property_ops = {
.read = bcm2835_property_read,
.write = bcm2835_property_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.valid.min_access_size = 4,
.valid.max_access_size = 4,
};
static const VMStateDescription vmstate_bcm2835_property = {
.name = TYPE_BCM2835_PROPERTY,
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_MACADDR(macaddr, BCM2835PropertyState),
VMSTATE_UINT32(addr, BCM2835PropertyState),
VMSTATE_BOOL(pending, BCM2835PropertyState),
VMSTATE_END_OF_LIST()
}
};
static void bcm2835_property_init(Object *obj)
{
BCM2835PropertyState *s = BCM2835_PROPERTY(obj);
memory_region_init_io(&s->iomem, OBJECT(s), &bcm2835_property_ops, s,
TYPE_BCM2835_PROPERTY, 0x10);
/*
* bcm2835_property_ops call into bcm2835_mbox, which in-turn reads from
* iomem. As such, mark iomem as re-entracy safe.
*/
s->iomem.disable_reentrancy_guard = true;
sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
sysbus_init_irq(SYS_BUS_DEVICE(s), &s->mbox_irq);
}
static void bcm2835_property_reset(DeviceState *dev)
{
BCM2835PropertyState *s = BCM2835_PROPERTY(dev);
s->pending = false;
}
static void bcm2835_property_realize(DeviceState *dev, Error **errp)
{
BCM2835PropertyState *s = BCM2835_PROPERTY(dev);
Object *obj;
obj = object_property_get_link(OBJECT(dev), "fb", &error_abort);
s->fbdev = BCM2835_FB(obj);
obj = object_property_get_link(OBJECT(dev), "dma-mr", &error_abort);
s->dma_mr = MEMORY_REGION(obj);
address_space_init(&s->dma_as, s->dma_mr, TYPE_BCM2835_PROPERTY "-memory");
/* TODO: connect to MAC address of USB NIC device, once we emulate it */
qemu_macaddr_default_if_unset(&s->macaddr);
bcm2835_property_reset(dev);
}
static Property bcm2835_property_props[] = {
DEFINE_PROP_UINT32("board-rev", BCM2835PropertyState, board_rev, 0),
DEFINE_PROP_STRING("command-line", BCM2835PropertyState, command_line),
DEFINE_PROP_END_OF_LIST()
};
static void bcm2835_property_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
device_class_set_props(dc, bcm2835_property_props);
dc->realize = bcm2835_property_realize;
dc->vmsd = &vmstate_bcm2835_property;
}
static const TypeInfo bcm2835_property_info = {
.name = TYPE_BCM2835_PROPERTY,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(BCM2835PropertyState),
.class_init = bcm2835_property_class_init,
.instance_init = bcm2835_property_init,
};
static void bcm2835_property_register_types(void)
{
type_register_static(&bcm2835_property_info);
}
type_init(bcm2835_property_register_types)