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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 /src | |
| 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.
Diffstat (limited to 'src')
| -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" |