[PATCH v2] ARM: rpi: parse useful data from vc fdt
Ahmad Fatoum
a.fatoum at pengutronix.de
Tue Jun 14 12:07:03 PDT 2022
Hello Daniel,
On 13.06.22 23:16, Daniel Brát wrote:
> Videocore first-stage loader on rpi passes us many useful information
> inside the vc fdt, including the real value of PM_RSTS register, not
> easily available by other means and which we can use to determine
> the reset cause.
> Also make the relevant funtions just print error/warning and continue
> in case of some errors, since the fdt from vc is now optional for
> barebox's basic function.
>
> Signed-off-by: Daniel Brát <danek.brat at gmail.com>
> ---
> arch/arm/boards/raspberry-pi/rpi-common.c | 200 +++++++++++++++++-----
> drivers/watchdog/bcm2835_wdt.c | 23 +--
> include/soc/bcm283x/wdt.h | 40 +++++
> 3 files changed, 200 insertions(+), 63 deletions(-)
> create mode 100644 include/soc/bcm283x/wdt.h
>
> diff --git a/arch/arm/boards/raspberry-pi/rpi-common.c b/arch/arm/boards/raspberry-pi/rpi-common.c
> index 12a4f4a0a..5d2196986 100644
> --- a/arch/arm/boards/raspberry-pi/rpi-common.c
> +++ b/arch/arm/boards/raspberry-pi/rpi-common.c
> @@ -23,13 +23,27 @@
> #include <linux/sizes.h>
> #include <globalvar.h>
> #include <asm/system_info.h>
> +#include <reset_source.h>
>
> #include <mach/core.h>
> #include <mach/mbox.h>
> #include <mach/platform.h>
>
> +#include <soc/bcm283x/wdt.h>
> +
> #include "lowlevel.h"
>
> +//https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#BOOT_ORDER
> +static const char * const boot_mode_names[] = {
[0x0] = "unknown"
I am not sure how devinfo global would look like if there are NULL
members.
> + [0x1] = "sd",
> + [0x2] = "net",
> + [0x3] = "rpiboot",
> + [0x4] = "usbmsd",
> + [0x5] = "usbc",
> + [0x6] = "nvme",
> + [0x7] = "http",
> +};
> +
> struct rpi_priv;
> struct rpi_machine_data {
> int (*init)(struct rpi_priv *priv);
> @@ -186,54 +200,151 @@ static int rpi_env_init(void)
> return 0;
> }
>
> -/* Extract /chosen/bootargs from the VideoCore FDT into vc.bootargs
> - * global variable. */
> -static int rpi_vc_fdt_bootargs(void *fdt)
> +/* Extract useful information from the VideoCore FDT we got.
> + * Some parameters are defined here:
> + * https://www.raspberrypi.com/documentation/computers/configuration.html#part4
> + */
> +static void rpi_vc_fdt_parse(void *fdt)
> {
> - int ret = 0;
> - struct device_node *root = NULL, *node;
> - const char *cmdline;
> + int ret, len;
> + struct device_node *root, *chosen, *bootloader;
> + enum reset_src_type rst_src = RESET_UKWN;
> + const char *str;
> + char *dynstr;
> + u32 num, *pnum;
>
> root = of_unflatten_dtb(fdt, INT_MAX);
> - if (IS_ERR(root)) {
> - ret = PTR_ERR(root);
> - root = NULL;
> - goto out;
> + if (IS_ERR(root))
> + return;
> +
> + str = of_get_property(root, "serial-number", &len);
> + if (!str) {
> + pr_warn("no 'serial-number' property found in vc fdt\n");
> + } else {
> + if (str[len - 1] == '\0') {
> + barebox_set_serial_number(str);
> + } else {
> + pr_warn("Malformed property 'serial-number' (not null "
> + "terminated)\n");
> + dynstr = xstrndup(str, len);
> + barebox_set_serial_number(dynstr);
> + free(dynstr);
> + }
> }
Sorry, some miscommunication here. Just use your normal approach in
the else clause. I had forgotten that some of these properties are
malformed. You can also drop the warning message about null
termination here.
>
> - node = of_find_node_by_path_from(root, "/chosen");
> - if (!node) {
> - pr_err("no /chosen node\n");
> - ret = -ENOENT;
> - goto out;
> + str = of_get_property(root, "model", &len);
> + if (!str) {
> + pr_warn("no 'model' property found in vc fdt\n");
> + } else {
> + if (str[len - 1] == '\0') {
> + barebox_set_model(str);
> + } else {
> + pr_warn("Malformed property 'model' (not null "
> + "terminated)\n");
As above.
> + dynstr = xstrndup(str, len);
> + barebox_set_model(dynstr);
> + free(dynstr);
> + }
> }
>
> - cmdline = of_get_property(node, "bootargs", NULL);
> - if (!cmdline) {
> - pr_err("no bootargs property in the /chosen node\n");
> - ret = -ENOENT;
> + chosen = of_find_node_by_path_from(root, "/chosen");
> + if (!chosen) {
> + pr_err("no '/chosen' node found in vc fdt\n");
> goto out;
> }
>
> - globalvar_add_simple("vc.bootargs", cmdline);
> + bootloader = of_find_node_by_name(chosen, "bootloader");
>
> - switch(cpu_architecture()) {
> - case CPU_ARCH_ARMv6:
> - globalvar_add_simple("vc.kernel", "kernel.img");
> - break;
> - case CPU_ARCH_ARMv7:
> - globalvar_add_simple("vc.kernel", "kernel7.img");
> - break;
> - case CPU_ARCH_ARMv8:
> - globalvar_add_simple("vc.kernel", "kernel8.img");
> - break;
> + str = of_get_property(chosen, "bootargs", &len);
> + if (!str) {
> + pr_warn("no 'bootargs' property in the /chosen node\n");
> + } else {
> + if (str[len - 1] == '\0') {
> + globalvar_add_simple("vc.bootargs", str);
> + } else {
> + pr_warn("Malformed property 'bootargs' (not null "
> + "terminated)\n");
> + globalvar_add_simple("vc.bootargs", xstrndup(str, len));
> + }
> + }
> +
> + str = of_get_property(chosen, "overlay_prefix", &len);
> + if (!str) {
> + pr_warn("no 'overlay_prefix' property in the /chosen node\n");
> + } else {
> + if (str[len - 1] == '\0'){
> + globalvar_add_simple("vc.overlay_prefix", str);
> + } else {
> + pr_warn("Malformed property 'overlay_prefix' (not null "
> + "terminated)\n");
> + globalvar_add_simple("vc.overlay_prefix",
> + xstrndup(str, len));
> + }
> + }
> +
> + str = of_get_property(chosen, "os_prefix", &len);
> + if (!str) {
> + pr_warn("no 'os_prefix' property in the /chosen node\n");
> + } else {
> + if (str[len - 1] == '\0') {
> + globalvar_add_simple("vc.os_prefix", str);
> + } else {
> + pr_warn("Malformed property 'os_prefix' (not null "
> + "terminated)\n");
> + globalvar_add_simple("vc.os_prefix", xstrndup(str, len));
> + }
> + }
> +
> + ret = of_property_read_u32(chosen, "boot-mode", &num);
> + if (ret && bootloader)
> + ret = of_property_read_u32(bootloader, "boot-mode", &num);
> + if (ret) {
> + pr_warn("'boot-mode' property not found\n");
> + } else {
> + pnum = xmalloc(sizeof(u32));
> + *pnum = num;
> + globalvar_add_simple_enum("vc.boot_mode", pnum,
> + boot_mode_names,
> + ARRAY_SIZE(boot_mode_names));
> }
>
> + ret = of_property_read_u32(chosen, "partition", &num);
> + if (ret && bootloader)
> + ret = of_property_read_u32(bootloader, "partition", &num);
> + if (ret) {
> + pr_warn("'partition' property not found\n");
> + } else {
> + pnum = xmalloc(sizeof(u32));
> + *pnum = num;
> + globalvar_add_simple_int("vc.boot_partition", pnum, "%u");
> + }
> +
> + if (IS_ENABLED(CONFIG_RESET_SOURCE)) {
> + ret = of_property_read_u32(chosen, "pm_rsts", &num);
> + if (ret && bootloader)
> + ret = of_property_read_u32(bootloader, "rsts", &num);
> +
> + if (ret) {
> + pr_warn("'pm_rsts'/'rsts' property not found\n");
> + } else {
> +/*
> + * https://github.com/raspberrypi/linux/issues/932#issuecomment-93989581
> + */
> + if (num & PM_RSTS_HADPOR_SET)
> + rst_src = RESET_POR;
> + else if (num & PM_RSTS_HADDR_SET)
> + rst_src = RESET_JTAG;
> + else if (num & PM_RSTS_HADWR_SET)
> + rst_src = RESET_WDG;
> + else if (num & PM_RSTS_HADSR_SET)
> + rst_src = RESET_RST;
> + reset_source_set(rst_src);
> + }
> + }
> out:
> if (root)
> of_delete_node(root);
> -
> - return ret;
> + return;
> }
>
> static void rpi_vc_fdt(void)
> @@ -241,7 +352,6 @@ static void rpi_vc_fdt(void)
> void *saved_vc_fdt;
> struct fdt_header *oftree;
> unsigned long magic, size;
> - int ret;
>
> /* VideoCore FDT was copied in PBL just above Barebox memory */
> saved_vc_fdt = (void *)(arm_mem_endmem_get());
> @@ -260,16 +370,23 @@ static void rpi_vc_fdt(void)
> return;
>
> size = be32_to_cpu(oftree->totalsize);
> - if (write_file("/vc.dtb", saved_vc_fdt, size)) {
> + if (write_file("/vc.dtb", saved_vc_fdt, size))
> pr_err("failed to save videocore fdt to a file\n");
> - return;
> - }
>
> - ret = rpi_vc_fdt_bootargs(saved_vc_fdt);
> - if (ret) {
> - pr_err("failed to extract bootargs from videocore fdt: %d\n",
> - ret);
> - return;
> + rpi_vc_fdt_parse(saved_vc_fdt);
> +}
> +
> +static void rpi_set_kernel_name(void) {
> + switch(cpu_architecture()) {
> + case CPU_ARCH_ARMv6:
> + globalvar_add_simple("vc.kernel", "kernel.img");
> + break;
> + case CPU_ARCH_ARMv7:
> + globalvar_add_simple("vc.kernel", "kernel7.img");
> + break;
> + case CPU_ARCH_ARMv8:
> + globalvar_add_simple("vc.kernel", "kernel8.img");
> + break;
> }
> }
>
> @@ -348,6 +465,7 @@ static int rpi_devices_probe(struct device_d *dev)
> armlinux_set_architecture(MACH_TYPE_BCM2708);
> rpi_env_init();
> rpi_vc_fdt();
> + rpi_set_kernel_name();
>
> if (dcfg && dcfg->init)
> dcfg->init(priv);
> diff --git a/drivers/watchdog/bcm2835_wdt.c b/drivers/watchdog/bcm2835_wdt.c
> index ece80837b..c6e6a289f 100644
> --- a/drivers/watchdog/bcm2835_wdt.c
> +++ b/drivers/watchdog/bcm2835_wdt.c
> @@ -10,28 +10,7 @@
> #include <restart.h>
> #include <watchdog.h>
>
> -#define PM_RSTC 0x1c
> -#define PM_RSTS 0x20
> -#define PM_WDOG 0x24
> -
> -#define PM_WDOG_RESET 0000000000
> -#define PM_PASSWORD 0x5a000000
> -#define PM_WDOG_TIME_SET 0x000fffff
> -#define PM_RSTC_WRCFG_CLR 0xffffffcf
> -#define PM_RSTC_WRCFG_SET 0x00000030
> -#define PM_RSTC_WRCFG_FULL_RESET 0x00000020
> -#define PM_RSTC_RESET 0x00000102
> -
> -#define PM_RSTS_HADPOR_SET 0x00001000
> -#define PM_RSTS_HADSRH_SET 0x00000400
> -#define PM_RSTS_HADSRF_SET 0x00000200
> -#define PM_RSTS_HADSRQ_SET 0x00000100
> -#define PM_RSTS_HADWRH_SET 0x00000040
> -#define PM_RSTS_HADWRF_SET 0x00000020
> -#define PM_RSTS_HADWRQ_SET 0x00000010
> -#define PM_RSTS_HADDRH_SET 0x00000004
> -#define PM_RSTS_HADDRF_SET 0x00000002
> -#define PM_RSTS_HADDRQ_SET 0x00000001
> +#include <soc/bcm283x/wdt.h>
>
> #define SECS_TO_WDOG_TICKS(x) ((x) << 16)
>
> diff --git a/include/soc/bcm283x/wdt.h b/include/soc/bcm283x/wdt.h
> new file mode 100644
> index 000000000..ce97b1eb5
> --- /dev/null
> +++ b/include/soc/bcm283x/wdt.h
> @@ -0,0 +1,40 @@
> +/*
> + * Copyright (C) 2017 Pengutronix, Lucas Stach <l.stach at pengutronix.de>
> + *
> + * Based on code from Carlo Caione <carlo at carlocaione.org>
> + */
> +
> +#ifndef __BCM2835_WDT_H
> +#define __BCM2835_WDT_H
> +
> +#define PM_RSTC 0x1c
> +#define PM_RSTS 0x20
> +#define PM_WDOG 0x24
> +
> +#define PM_WDOG_RESET 0000000000
> +#define PM_PASSWORD 0x5a000000
> +#define PM_WDOG_TIME_SET 0x000fffff
> +#define PM_RSTC_WRCFG_CLR 0xffffffcf
> +#define PM_RSTC_WRCFG_SET 0x00000030
> +#define PM_RSTC_WRCFG_FULL_RESET 0x00000020
> +#define PM_RSTC_RESET 0x00000102
> +
> +#define PM_RSTS_HADPOR_SET 0x00001000
> +#define PM_RSTS_HADSRH_SET 0x00000400
> +#define PM_RSTS_HADSRF_SET 0x00000200
> +#define PM_RSTS_HADSRQ_SET 0x00000100
> +#define PM_RSTS_HADWRH_SET 0x00000040
> +#define PM_RSTS_HADWRF_SET 0x00000020
> +#define PM_RSTS_HADWRQ_SET 0x00000010
> +#define PM_RSTS_HADDRH_SET 0x00000004
> +#define PM_RSTS_HADDRF_SET 0x00000002
> +#define PM_RSTS_HADDRQ_SET 0x00000001
> +
> +#define PM_RSTS_HADDR_SET \
> + (PM_RSTS_HADDRQ_SET | PM_RSTS_HADDRF_SET | PM_RSTS_HADDRH_SET)
> +#define PM_RSTS_HADWR_SET \
> + (PM_RSTS_HADWRQ_SET | PM_RSTS_HADWRF_SET | PM_RSTS_HADWRH_SET)
> +#define PM_RSTS_HADSR_SET \
> + (PM_RSTS_HADSRQ_SET | PM_RSTS_HADSRF_SET | PM_RSTS_HADSRH_SET)
> +
> +#endif
--
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