u-boot.git/arch/arm/lib, branch v2022.07

arm: gic_v2: Skip gic_init_secure when cpu is not in el3

2022-05-23T13:33:10Z

This would prevent configuring non-secure regs in case gic security extensions are not emulated in Qemu. Signed-off-by: Sai Pavan Boddu Signed-off-by: Michal Simek

arm: Add new config option ARCH_VERY_EARLY_INIT

2022-05-16T09:31:33Z

When this option is set then ARM _main() function would call arch_very_early_init() function at the beginning. It would be before calling any other functions like debug_uart_init() and also before initializing C runtime environment. Signed-off-by: Pali Rohár Reviewed-by: Stefan Roese

arm: Do not compile vector table when SYS_NO_VECTOR_TABLE is enabled

2022-04-21T10:31:36Z

Vector table is not used when SYS_NO_VECTOR_TABLE is enabled. So do not compile it and reduce image size. Signed-off-by: Pali Rohár

arm: init: save previous bootloader data

2022-04-04T18:53:26Z

When u-boot is used as a chain-loaded bootloader (replacing OS kernel), previous bootloader leaves data in RAM, that can be reused. For example, on recent arm linux system, when chainloading u-boot, there are initramfs and fdt in RAM prepared for OS booting. Initramfs may be modified to store u-boot's payload, thus providing the ability to use chainloaded u-boot to boot OS without any storage support. Two config options added: - SAVE_PREV_BL_INITRAMFS_START_ADDR saves initramfs start address to 'prevbl_initrd_start_addr' environment variable - SAVE_PREV_BL_FDT_ADDR saves fdt address to 'prevbl_fdt_addr' environment variable Signed-off-by: Dzmitry Sankouski Cc: Tom Rini

arm64: Catch non-emulated semihosting calls

2022-04-01T20:56:53Z

If a debugger is not attached to U-Boot, semihosting calls will raise a synchronous abort exception. Try to catch this and disable semihosting so we can e.g. use another uart if one is available. In the immediate case, we return an error, since it is not always possible to check for semihosting beforehand (debug uart, user-initiated load command, etc.) We handle all possible semihosting instructions, which is probably overkill. However, we do need to keep track of what instruction set we're using so that we don't suppress an actual error. A future enhancement could try to determine semihosting capability by inspecting the processor state. There's an example of this at [1] for RISC-V. The equivalent for ARM would inspect the monitor modei enable/select bits of the DSCR. However, as the article notes, an exception handler is still helpful in order to catch disconnected debuggers. [1] https://tomverbeure.github.io/2021/12/30/Semihosting-on-RISCV.html#avoiding-hangs-when-a-debugger-is-not-connected Signed-off-by: Sean Anderson

arm: smh: Add option to detect semihosting

2022-04-01T20:56:53Z

These functions are intended to support detecting semihosting and falling back gracefully to alternative implementations. The test starts by making semihosting call. SYS_ERRNO is chosen because it should not mutate any state. If this semihosting call results in an exception (rather than being caught by the debugger), then the exception handler should call disable_semihosting() and resume execution after the call. Ideally, this would just be part of semihosting by default, and not a separate config. However, to reduce space ARM SPL doesn't include exception vectors by default. This means we can't detect if a semihosting call failed unless we enable them. To avoid forcing them to be enabled, we use a separate config option. It might also be possible to try and detect whether a debugger has enabled (by reading HDE from DSCR), but I wasn't able to figure out a way to do this from all ELs. This patch just introduces the generic code to handle detection. The next patch will implement it for arm64 (but not arm32). Signed-off-by: Sean Anderson

arm64: Save esr in pt_regs

2022-04-01T20:56:53Z

To avoid passing around an extra register everywhere, save esr in pt_regs like the rest. For proper alignment we need to have a second (unused) register. All the printfs have to be adjusted, since it's now an unsigned long and not an int. Signed-off-by: Sean Anderson

arm: smh: Add some functions for working with the host console

2022-04-01T19:03:13Z

This adds three wrappers around the semihosting commands for reading and writing to the host console. We use the more standard getc/putc/puts names instead of readc/writec/write0 for familiarity. Signed-off-by: Sean Anderson

arm: smh: Remove smhload command

2022-04-01T19:03:13Z

This command's functionality is now completely implemented by the standard fs load command. Convert the vexpress64 boot command (which is the only user) and remove the implementation. Signed-off-by: Sean Anderson

cmd: fdt: Use start/size for chosen instead of start/end

2022-04-01T19:03:13Z

Most U-Boot command deal with start/size instead of start/end. Convert the "fdt chosen" command to use these semantics as well. The only user of this subcommand is vexpress, so convert the smhload command to use this as well. We don't bother renaming the variable in vexpress64's bootcommand, since it will be rewritten in the next commit. Signed-off-by: Sean Anderson