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| author | Kevin O'Connor <kevin@koconnor.net> | 2008-08-17 10:50:57 -0400 |
|---|---|---|
| committer | Kevin O'Connor <kevin@koconnor.net> | 2008-08-17 10:50:57 -0400 |
| commit | 484270d5ec465d1b5c02d8d60df9e46578e408e7 (patch) | |
| tree | 08dce479aa76eb9583e0be02409f3c6866d6b177 | |
| parent | c43bcba21546a1e65e1422b44de746f1671e076c (diff) | |
| download | seabios-hppa-484270d5ec465d1b5c02d8d60df9e46578e408e7.zip seabios-hppa-484270d5ec465d1b5c02d8d60df9e46578e408e7.tar.gz seabios-hppa-484270d5ec465d1b5c02d8d60df9e46578e408e7.tar.bz2 | |
Improve smp detection code.
Use 'lock incw' to ensure proper synchronization between cpus.
Jump to the 0xf0000 segment for the halt (to ensure halt code isn't overwritten).
Improve code comments.
| -rw-r--r-- | src/romlayout.S | 10 | ||||
| -rw-r--r-- | src/smpdetect.c | 12 |
2 files changed, 16 insertions, 6 deletions
diff --git a/src/romlayout.S b/src/romlayout.S index 6eda036..3eaf725 100644 --- a/src/romlayout.S +++ b/src/romlayout.S @@ -318,6 +318,16 @@ post32: .code16gcc +// Shutdown a CPU. We want this in the 0xf000 section to ensure that +// the code wont be overwritten with something else. (Should +// something spurious wake up the CPU, we want to be sure that the hlt +// insn will still be present and will shutdown the CPU.) + .global permanent_halt +permanent_halt: + cli +1: hlt + jmp 1b + /**************************************************************** * GDT and IDT tables diff --git a/src/smpdetect.c b/src/smpdetect.c index c0f0903..db47943 100644 --- a/src/smpdetect.c +++ b/src/smpdetect.c @@ -54,12 +54,12 @@ asm( " .code16\n" "smp_ap_boot_code_start:\n" - " xor %ax, %ax\n" - " mov %ax, %ds\n" - " incw " __stringify(BUILD_CPU_COUNT_ADDR) "\n" - "1:\n" - " hlt\n" - " jmp 1b\n" + // Increament the counter at BUILD_CPU_COUNT_ADDR + " xorw %ax, %ax\n" + " movw %ax, %ds\n" + " lock incw " __stringify(BUILD_CPU_COUNT_ADDR) "\n" + // Halt the processor. + " ljmpl $" __stringify(SEG_BIOS) ", $(permanent_halt - " __stringify(BUILD_BIOS_ADDR) ")\n" "smp_ap_boot_code_end:\n" " .code32\n" |